Alzheimer Disease: Birks J

Birks J, Grimley Evans J, Iakovidou V, Tsolaki M, Holt FE. · Centre for Statistics in Medicine, University of Oxford, Wolfson College, Linton Road, Oxford, UK, OX2 6UD. · Cochrane Database Syst Rev. · Pubmed #19370562 No free full text.

Abstract: BACKGROUND: Alzheimer's disease (AD) is the commonest cause of dementia affecting older people. One of the therapeutic strategies aimed at ameliorating the clinical manifestations of Alzheimer's disease is to enhance cholinergic neurotransmission in relevant parts of the brain by the use of cholinesterase inhibitors to delay the breakdown of acetylcholine released into synaptic clefts. Tacrine, the first of the cholinesterase inhibitors to undergo extensive trials for this purpose, was associated with significant adverse effects including hepatotoxicity. Other cholinesterase inhibitors, including rivastigmine, with superior properties in terms of specificity of action and low risk of adverse effects, have now been introduced. Rivastigmine has received approval for use in 60 countries including all member states of the European Union and the USA. OBJECTIVES: To determine the clinical efficacy and safety of rivastigmine for patients with dementia of Alzheimer's type. SEARCH STRATEGY: The Specialized Register of the Cochrane Dementia and Cognitive Improvement Group (CDCIG), The Cochrane Library, MEDLINE, EMBASE, PsycINFO, CINAHL and LILACS were searched on 27 March 2008 using the terms: Rivastigmine OR exelon OR ENA OR "SDZ ENA 713" . The CDCIG Specialized Register contains records from all major health care databases (The Cochrane Library, MEDLINE, EMBASE, PsycINFO, CINAHL, LILACS) as well as from many clinical trials registries and grey literature sources. SELECTION CRITERIA: All unconfounded, double-blind, randomized trials in which treatment with rivastigmine was administered to patients with dementia of the Alzheimer's type for more than two weeks and its effects compared with those of placebo in a parallel group of patients. DATA COLLECTION AND ANALYSIS: One reviewer (JSB) applied study selection criteria, assessed the quality of studies and extracted data. MAIN RESULTS: Nine trials, involving 4775 participants, were included in the analyses. Use of rivastigmine in high doses was associated with statistically significant benefits on several measures. High-dose rivastigmine (6 to 12 mg daily) was associated with a two-point improvement in cognitive function on the ADAS-Cog score compared with placebo (weighted mean difference -1.99, 95% confidence interval -2.49 to -1.50, on an intention-to-treat basis) and a 2.2 point improvement in activities of daily living assessed on the Progressive Deterioration Scale (weighted mean difference -2.15, 95% confidence interval -3.16 to -1.13, on an intention-to-treat basis) at 26 weeks. At lower doses (4 mg daily or lower) differences were in the same direction but were statistically significant only for cognitive function. There were statistically significantly higher numbers of events of nausea, vomiting, diarrhoea, anorexia, headache, syncope, abdominal pain and dizziness among patients taking high-dose rivastigmine than among those taking placebo. There was some evidence that adverse events might be less common with more frequent, smaller doses of rivastigmine. The 2008 update includes a new study testing two types of rivastigmine transdermal patch, one delivering a higher dose than previously tested (17.4 mg/day) and a smaller patch delivering 9.6 mg/day. The efficacy of the smaller patch was not significantly different compared with the capsules of similar daily dose, but was associated with significantly fewer adverse events of nausea, vomiting, dizziness and asthenia. The efficacy of the larger patch was not significantly different compared with the smaller patch, but the smaller patch was associated with significantly fewer adverse events of nausea, vomiting, weight loss and dizziness. There appears to be advantages associated with the smaller patch compared with both the higher dose patch and the 6-12 mg/day capsules. AUTHORS' CONCLUSIONS: Rivastigmine appears to be beneficial for people with mild to moderate Alzheimer's disease. In comparisons with placebo, improvements were seen in the rate of decline of cognitive function, activities of daily living, and severity of dementia with daily doses of 6 to 12 mg. Adverse events were consistent with the cholinergic actions of the drug. A transdermal patch has been tested in one trial, and there is evidence that the lower dose smaller patch is associated with fewer side effects than the capsules or the higher dose larger patch and has comparable efficacy to both. This review has not examined economic data.

Qizilbash N, Birks J, Lopez Arrieta J, Lewington S, Szeto S. · SmithKline Beecham, New Frontiers Science Park (South), Third Avenue, Harlow, Essex, UK, CM19 5AW. · Cochrane Database Syst Rev. · Pubmed #17636619 No free full text.

Abstract: BACKGROUND: Tacrine is one of the first drugs to be widely marketed for the loss of memory and intellectual decline in Alzheimer's disease, often accompanied by abnormal behaviour and physical decline. The alleged success of tacrine in the treatment of these symptoms has been heralded as confirmation of the cholinergic theory of Alzheimer's disease. The efficacy of tacrine for symptoms of dementia remains controversial. This is reflected by the low rate of prescription of tacrine in countries where it is approved and the lack of approval by several regulatory authorities in Europe and elsewhere. The uncertainty about the efficacy of tacrine is due to the difficulties in interpretation of the results from the clinical trials. The reasons for this are the small effects of tacrine compared to placebo for all outcomes; the high incidence of adverse events; the lack of benefit observed in several trials; the use of cross-over designs and their associated methodological problems in a disease like dementia; the use of different measurement scales to assess outcome in different trials; and the problem of high dropout rates. OBJECTIVES: To determine the clinical efficacy of tacrine for the symptoms of Alzheimer's disease. SEARCH STRATEGY: The Cochrane Dementia Group Register of Clinical Trials was searched using the terms 'tacrine', 'tetrahydroaminoacridine' and 'THA' (see the Group's search strategy for full details). SELECTION CRITERIA: All unconfounded, double-blind, randomized trials in which treatment with tacrine was administered for more than a day and compared to placebo in patients with dementia of the Alzheimer's type. DATA COLLECTION AND ANALYSIS: Data were extracted independently by two reviewers, pooled if appropriate and possible, and the pooled odds ratios (95%CI) or the average differences (95%CI) were estimated. Where possible, intention-to-treat data were used. MAIN RESULTS: This review produced no clear results. The results were compatible with tacrine producing improvement, no change or even harm for those with Alzheimer's disease. It was not possible to use many of the published results in a combined analysis.For measures of overall clinical improvement, the intention-to-treat analyses failed to detect any difference between tacrine and placebo (OR 0.87; 95%CI 0.61 - 1.23).Behavioural disturbance, as measured by the Alzheimer's Disease Assessment Scale-noncognitive, failed to detect any difference between tacrine and placebo (SMD -0.04; 95%CI -0.52 - 0.43).For cognition function, the effect of tacrine was not statistically significantly different from placebo for the MiniMental State Examination score (0-30; high =good) (SMD 0.14; 95%CI -0.02 - 0.30) and was barely statistically significantly in favour of treatment for the Alzheimer's Disease Assessment Scale-cognitive scale (SMD -0.22; 95%CI -0.32 - -0.13).Adverse events were not reported in a systematic way in the different trials, making formal comparison difficult. Raised serum liver enzymes was the major reason for withdrawal. The odds ratio for withdrawal due to an adverse event was significantly different from one, the control group experienced fewer events (OR 5.7; 95%CI 4.1-7.9). Gastrointestinal side effects (diarrhoea, anorexia, dyspepsia and abdominal pain) were the other major cause of adverse events and for withdrawal, and the odds ratio for withdrawal was also significantly different from one in favour of the control group (OR 3.8; 95%CI 2.8-5.1). No deaths were reported in any of the studies during the trial period, up to six months. AUTHORS' CONCLUSIONS: This review provides no convincing evidence that tacrine is a useful treatment for the symptoms of Alzheimer's disease. However, as so few trials presented data in a format suitable for pooling, the results of this review may be modified when further data from all relevant trials are included. There is an urgent need for the independent evaluation of the data already existing in the trials but not accessible through published or grouped data. An independent meta-analysis of the individual-patient data is required.The results and conclusions of this update are unaltered by further searching as the additional studies do not add any further valid/eligible data.

Birks J. · University of Oxford, Department of Clinical Geratology, Radcliffe Infirmary, Woodstock Road, Oxford, UK, OX2 6HE. · Cochrane Database Syst Rev. · Pubmed #16437532 No free full text.

Abstract: BACKGROUND: Since the introduction of the first cholinesterase inhibitor (ChEI) in 1997, most clinicians and probably most patients would consider the cholinergic drugs, donepezil, galantamine and rivastigmine, to be the first line pharmacotherapy for mild to moderate Alzheimer's disease.The drugs have slightly different pharmacological properties, but they all work by inhibiting the breakdown of acetylcholine, an important neurotransmitter associated with memory, by blocking the enzyme acetylcholinesterase. The most that these drugs could achieve is to modify the manifestations of Alzheimer's disease. Cochrane reviews of each ChEI for Alzheimer's disease have been completed (Birks 2005, Birks 2005b and Loy 2005). Despite the evidence from the clinical studies and the intervening clinical experience the debate on whether ChEIs are effective continues. OBJECTIVES: To assess the effects of donepezil, galantamine and rivastigmine in people with mild, moderate or severe dementia due to Alzheimer's disease. SEARCH STRATEGY: The Cochrane Dementia and Cognitive Improvement Group's Specialized Register was searched using the terms 'donepezil', 'E2020' , 'Aricept' , galanthamin* galantamin* reminyl, rivastigmine, exelon, "ENA 713" and ENA-713 on 12 June 2005. This Register contains up-to-date records of all major health care databases and many ongoing trial databases. SELECTION CRITERIA: All unconfounded, blinded, randomized trials in which treatment with a ChEI was compared with placebo or another ChEI for patients with mild, moderate or severe dementia due to Alzheimer's disease. DATA COLLECTION AND ANALYSIS: Data were extracted by one reviewer (JSB), pooled where appropriate and possible, and the pooled treatment effects, or the risks and benefits of treatment estimated. MAIN RESULTS: The results of 13 randomized, double blind, placebo controlled trials demonstrate that treatment for periods of 6 months and one year, with donepezil, galantamine or rivastigmine at the recommended dose for people with mild, moderate or severe dementia due to Alzheimer's disease produced improvements in cognitive function, on average -2.7 points (95%CI -3.0 to -2.3), in the midrange of the 70 point ADAS-Cog Scale. Study clinicians blind to other measures rated global clinical state more positively in treated patients. Benefits of treatment were also seen on measures of activities of daily living and behaviour. None of these treatment effects are large.There is nothing to suggest the effects are less for patients with severe dementia or mild dementia, although there is very little evidence for other than mild to moderate dementia.More patients leave ChEI treatment groups, approximately 29 %, on account of adverse events than leave the placebo groups (18%).There is evidence of more adverse events in total in the patients treated with a ChEI than with placebo. Although many types of adverse event were reported, nausea, vomiting, diarrhoea, were significantly more frequent in the ChEI groups than in placebo.There are four studies, all supported by one of the pharmaceutical companies, in which two ChEIs were compared, two studies of donepezil compared with galantamine, and two of donepezil compared with rivastigmine. In three studies the patients were not blinded to treatment, only the fourth, DON vs RIV/Bullock is double blind. Two of the studies provide little evidence, they are of 12 weeks duration, which is barely long enough to complete the drug titration. There is no evidence from DON vs GAL/Wilcock of a treatment difference between donepezil and galantamine at 52 weeks for cognition, activities of daily living, the numbers who leave the trial before the end of treatment, the number who suffer any adverse event, or any specific adverse event.There is no evidence from DON vs RIV/Bullock of a difference between donepezil and rivastigmine for cognitive function, activities of daily living and behavioural disturbance at two years. Fewer patients suffer adverse events on donepezil than rivastigmine. AUTHORS' CONCLUSIONS: The three cholinesterase inhibitors are efficacious for mild to moderate Alzheimer's disease. It is not possible to identify those who will respond to treatment prior to treatment. There is no evidence that treatment with a ChEI is not cost effective. Despite the slight variations in the mode of action of the three cholinesterase inhibitors there is no evidence of any differences between them with respect to efficacy. There appears to be less adverse effects associated with donepezil compared with rivastigmine. It may be that galantamine and rivastigmine match donepezil in tolerability if a careful and gradual titration routine over more than three months is used. Titration with donepezil is more straightforward and the lower dose may be worth consideration.

Craig D, Birks J. · Whitla Medical Building, School of Medicine and Dentistry, Queen's University of Belfast, 97 Lisburn Road, Belfast, UK, BT9 7BL. · Cochrane Database Syst Rev. · Pubmed #16437493 No free full text.

Abstract: BACKGROUND: Vascular dementia is the second most common form of dementia. Cholinesterase inhibitors modestly improve a broad range of symptoms in some patients with Alzheimer's disease through enhancement of cholinergic neurotransmission. These drugs may also be beneficial in vascular dementia as reductions in acetylcholine and acetyltransferase activity have been reported. OBJECTIVES: To assess the efficacy of galantamine in the treatment of people with vascular cognitive impairment or vascular dementia or "mixed" dementia. SEARCH STRATEGY: Trials were identified from a search of the Specialized Register of the Cochrane Dementia and Cognitive Improvement Group on 19 April 2005 using the terms: galantamine. galanthamine, reminyl. All major health care databases and many ongoing trial databases within the scope of the group are searched regularly to keep this Register up to date. SELECTION CRITERIA: All unconfounded randomised double-blind trials comparing galantamine with placebo were eligible for inclusion. DATA COLLECTION AND ANALYSIS: Two RCTs fulfilling the inclusion criteria were included in this review. Two reviewers independently extracted the data from these two inclusion studies. MAIN RESULTS: Two trials employing randomized, double-blind, parallel-group methodology were included. GAL-INT-6 reported sub-group data for a pure population of vascular dementia patients showing no significant differences in Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog/11) and Clinician's Interview-based Impression of Change (CIBIC-plus) when galantamine was compared against placebo. When data combining patients with vascular dementia diagnosed according to recognised criteria with a population of patients with Alzheimer's disease and coincidental radiographic findings of cerebrovascular disease was analysed, statistically significant improvements in cognition (ADAS-cog), global functioning (CIBIC-plus), activities of daily living (DAD) and behaviour (NPI) were noted. In the galantamine treated group, significantly higher numbers of patients dropped out and withdrew due to an adverse event.Limited data was available at the time of publication for a second larger trial (GAL-INT-26) involving patients with vascular dementia diagnosed using standard criteria. Statistically significant benefits favouring galantamine over placebo in assessments of cognition (ADAS-cog/11; p < 0.001) and executive function (Executive Interview, EXIT-25, p = 0.041) were recorded. No differences in outcome in measures of behaviour (Neuropsychiatric Inventory, NPI), daily living (Alzheimer's Disease Cooperative Study-Activities of Daily Living inventory, ADCS-ADL) and global functioning (CIBIC-plus) in this trial were seen. AUTHORS' CONCLUSIONS: Limited data were available when considering the impact of galantamine on vascular dementia or vascular cognitive impairment. The data available at the time of review suggest some advantage over placebo in the areas of cognition and executive functioning in one trial but this was not seen in a second trial which included smaller numbers of relevant patients. In both considered trials galantamine produced higher rates of gastrointestinal side-effects. More studies are needed before firm conclusions can be drawn.

Birks J, Harvey RJ. · University of Oxford, Department of Clinical Geratology, Radcliffe Infirmary, Woodstock Road, Oxford, UK, OX2 6HE. · Cochrane Database Syst Rev. · Pubmed #16437430 No free full text.

Abstract: BACKGROUND: Alzheimer's disease is the most common cause of dementia in older people. One of the aims of therapy is to inhibit the breakdown of a chemical neurotransmitter, acetylcholine, by blocking the relevant enzyme. This can be done by a group of chemicals known as cholinesterase inhibitors. OBJECTIVES: The objective of this review is to assess whether donepezil improves the well-being of patients with dementia due to Alzheimer's disease. SEARCH STRATEGY: The Cochrane Dementia and Cognitive Improvement Group's Specialized Register was searched using the terms 'donepezil', 'E2020' and 'Aricept' on 12 June 2005. This Register contains up-to-date records of all major health care databases and many ongoing trial databases.Members of the Donepezil Study Group and Eisai Inc were contacted. SELECTION CRITERIA: All unconfounded, double-blind, randomized controlled trials in which treatment with donepezil was compared with placebo for patients with mild, moderate or severe dementia due to Alzheimer's disease. DATA COLLECTION AND ANALYSIS: Data were extracted by one reviewer (JSB), pooled where appropriate and possible, and the pooled treatment effects, or the risks and benefits of treatment estimated. MAIN RESULTS: 23 trials are included, involving 5272 participants. Most trials were of 6 months or less duration in selected patients. Available outcome data cover domains including cognitive function, activities of daily living, behaviour , global clinical state and health care resource costs.For cognition there is a statistically significant improvement for both 5 and 10 mg/day of donepezil at 24 weeks compared with placebo on the ADAS-Cog scale (-2.01 points MD, 95%CI -2.69 to -1.34, p<0.00001); -2.80 points, MD 95% CI -3.74 to -2.10, p<0.00001) and for 10 mg/day donepezil compared with placebo at 52 weeks (1.84 MMSE points, 95% CI, 0.53 to 3.15, p=0.006).The results show some improvement in global clinical state (assessed by a clinician) in people treated with 5 and 10 mg/day of donepezil compared with placebo at 24 weeks for the number of patients showing improvement or no change (OR 2.18, 95% CI 1.53 to 3.11, p=<0.0001, OR 2.38, 95% CI 1.78 to 3.19, p<0.00001). Benefits of treatment were also seen on measures of activities of daily living and behaviour, but not on the quality of life score .There were significantly more withdrawals before the end of treatment from the 10 mg/day (but not the 5 mg/day) donepezil group compared with placebo which may have resulted in some overestimation of beneficial changes at 10 mg/day. Benefits on the 10 mg/day dose were marginally larger than on the 5 mg/day dose. Two studies presented results for health resource use, and the associated costs. There were no significant differences between treatment and placebo for any item, the cost of any item, and for the total costs, and total costs including the informal carer costs. A variety of adverse effects were recorded, with more incidents of nausea, vomiting, diarrhoea, muscle cramps, dizziness, fatigue and anorexia (significant risk associated with treatment) in the 10 mg/day group compared with placebo but very few patients left a trial as a direct result of the intervention. AUTHORS' CONCLUSIONS: People with mild, moderate or severe dementia due to Alzheimer's disease treated for periods of 12, 24 or 52 weeks with donepezil experienced benefits in cognitive function, activities of daily living and behaviour. Study clinicians rated global clinical state more positively in treated patients, and measured less decline in measures of global disease severity. There is some evidence that use of donepezil is neither more nor less expensive compared with placebo when assessing total health care resource costs. Benefits on the 10 mg/day dose were marginally larger than on the 5 mg/day dose. Taking into consideration the better tolerability of the 5 mg/day donepezil compared with the 10 mg/day dose, together with the lower cost, the lower dose may be the better option. The debate on whether donepezil is effective continues despite the evidence of efficacy from the clinical studies because the treatment effects are small and are not always apparent in practice .

Whitehead A, Perdomo C, Pratt RD, Birks J, Wilcock GK, Evans JG. · The University of Reading, Medical and Pharmaceutical Statistics Research Unit, Reading, UK. · Int J Geriatr Psychiatry. · Pubmed #15254918 No free full text.

Abstract: BACKGROUND: The objective was to evaluate the efficacy and tolerability of donepezil (5 and 10 mg/day) compared with placebo in alleviating manifestations of mild to moderate Alzheimer's disease (AD). METHOD: A systematic review of individual patient data from Phase II and III double-blind, randomised, placebo-controlled studies of up to 24 weeks and completed by 20 December 1999. The main outcome measures were the ADAS-cog, the CIBIC-plus, and reports of adverse events. RESULTS: A total of 2376 patients from ten trials were randomised to either donepezil 5 mg/day (n = 821), 10 mg/day (n = 662) or placebo (n = 893). Cognitive performance was better in patients receiving donepezil than in patients receiving placebo. At 12 weeks the differences in ADAS-cog scores were 5 mg/day-placebo: - 2.1 [95% confidence interval (CI), - 2.6 to - 1.6; p < 0.001], 10 mg/day-placebo: - 2.5 ( - 3.1 to - 2.0; p < 0.001). The corresponding results at 24 weeks were - 2.0 ( - 2.7 to - 1.3; p < 0.001) and - 3.1 ( - 3.9 to - 2.4; p < 0.001). The difference between the 5 and 10 mg/day doses was significant at 24 weeks (p = 0.005). The odds ratios (OR) of improvement on the CIBIC-plus at 12 weeks were: 5 mg/day-placebo 1.8 (1.5 to 2.1; p < 0.001), 10 mg/day-placebo 1.9 (1.5 to 2.4; p < 0.001). The corresponding values at 24 weeks were 1.9 (1.5 to 2.4; p = 0.001) and 2.1 (1.6 to 2.8; p < 0.001). Donepezil was well tolerated; adverse events were cholinergic in nature and generally of mild severity and brief in duration. CONCLUSION: Donepezil (5 and 10 mg/day) provides meaningful benefits in alleviating deficits in cognitive and clinician-rated global function in AD patients relative to placebo. Increased improvements in cognition were indicated for the higher dose.

Evans JG, Wilcock G, Birks J. · Cochrane Dementia and Cognitive Improvement Group, University of Oxford, UK. · Int J Neuropsychopharmacol. · Pubmed #15228642 No free full text.

Abstract: Dementia is an acquired global impairment of cognitive capacities. Approximately 5% of people aged over 65 yr are affected by dementia, and some 70% of cases are thought to be due primarily to Alzheimer's disease. Descriptions of the clinical manifestations of Alzheimer's disease have been increasingly refined in the last decade but there is no diagnostic test for what remains fundamentally a pathologically defined condition. At the present time interventions for Alzheimer's disease are limited to those that modify the manifestations of the disease, and foremost amongst the candidates available are the cholinesterase inhibitors. The rationale for the use of cholinergic drugs for Alzheimer's disease lies in enhancing the secretion of, or prolonging the half-life of, acetylcholine in the brain. Several potential compounds have been tested, but short half-lives and a high incidence of cholinergic and other adverse effects have eliminated most. Only three are widely licensed for use, donepezil, galantamine and rivastigmine. Their efficacy is relatively modest. These drugs have been tested in 32 randomized, placebo-controlled trials. The trials assess cognitive function primarily, and in addition they may assess global function, activities of daily living, quality of life and behavioural disturbance typically over 3 or 6 months. The performance of each drug is summarized in a Cochrane review, a systematic review carried out according to strict guidelines. There was a significant benefit in favour of treatment compared with placebo for cognition and activities of daily living, but withdrawals due to adverse events were significantly higher for treatment than placebo for all three drugs. There is little evidence from direct comparisons between the three drugs. There are several economic analyses of the cost-effectiveness of these drugs, but the findings cannot be considered robust owing to inadequate data. A range of other pharmacological treatments have been tested, including selegiline, piracetam, vitamin E, Ginkgo biloba, anti-inflammatory drugs and hormone replacement therapy, but, so far, Cochrane reviews have not established the efficacy of these interventions for Alzheimer's disease. A Cochrane review of memantine shows benefits on cognitive and global function of the same order of magnitude as seen for the cholinesterase inhibitors. Memantine has been licensed in Europe for treatment of patients with moderately severe to severe Alzheimer's disease.

Birks J, Wilcock GG. · Department of Clinical Geratology, University of Oxford, Radcliffe Infirmary, Woodstock Road, Oxford, UK, OX2 6HE. · Cochrane Database Syst Rev. · Pubmed #15106259 No free full text.

Abstract: BACKGROUND: Alzheimer's disease (AD) is the commonest cause of dementia affecting older people. One of the therapeutic strategies aimed at ameliorating the clinical manifestations of Alzheimer's disease is to enhance cholinergic neurotransmission in relevant parts of the brain by the use of cholinesterase inhibitors to delay the breakdown of acetylcholine released into synaptic clefts. Tacrine, the first of the cholinesterase inhibitors to undergo extensive trials for this purpose, was associated with significant adverse effects including hepatotoxicity. Velnacrine is a derivative of tacrine. OBJECTIVES: To determine the clinical efficacy and safety of velnacrine for patients with dementia of Alzheimer's type. SEARCH STRATEGY: The trials were identified from a last updated search of the Specialized Register of the Cochrane Dementia and Cognitive Improvement Group on 8 January 2004 using the terms velnacr* and 'HP 029'. The CDCIG SR is regularly updated and contains records from all major health care databases and a great many ongoing trial databases. SELECTION CRITERIA: All unconfounded, double-blind, randomized trials in which treatment with velnacrine was administered to patients with dementia of the Alzheimer's type for more than two weeks and its effects compared with those of placebo in a parallel group of patients. DATA COLLECTION AND ANALYSIS: One reviewer (JSB) applied study selection criteria, assessed the quality of studies and extracted data. MAIN RESULTS: Four trials, involving 899 participants, were included. Cutler 1990 reported only the adverse events, and omitted the results for the placebo group. Medication was stopped for all in the highest dose group after the fourth day because one member suffered a tonic seizure. It is not possible to report any comparisons with placebo. Antuono 1995 reported benefit for velnacrine at endpoint for the CGI-C, and the Physical Self-maintenance Scale (PGIR), but not for the Carers Assessment of Time Activity (CATS). These results could not be checked because the relevant information was not reported, and we cannot assess the effect on the results of the higher number of non-completers from the velnacrine group. Treatment was discontinued because of safety reasons in 135 patients, mostly due to an abnormal liver function tests. There was a significant difference in favour of placebo compared with the combined treatment group for the number with an abnormal liver function test before the end of treatment at 24 weeks [105/297 vs 4/152, OR =20.23, 95% CI 7.29 to 56.18, p<0.00001]. There was a significant difference in favour of placebo compared with the combined treatment group for the number of withdrawals before the end of treatment at 24 weeks [130/297 vs 39/152, OR =2.26, 95% CI 1.47 to 3.47, p=0.0002].Results are available for the dose replication phases of Zemlan 1996a and Zemlan 1996b. All the patients had taken velnacrine within two weeks prior to this phase and were identified as responders to velnacrine defined by improvement on the ADAS-Cog. Both studies reported a significant benefit for velnacrine compared with placebo for the ADAS-cog, but the results could not be checked because the relevant information was not reported. Neither study reported any benefit for velnacrine for the other efficacy measures. There was a significant difference in favour of placebo compared with the treatment group for the number with elevated liver transaminases before the end of treatment at 6 weeks [45/153 vs 29/156, OR =1.82, 95% CI 1.07 to 3.11, p=0.03]. There was a significant difference in favour of placebo compared with the treatment group for the number of withdrawals before the end of treatment at 6 weeks [68/211 vs 47/215, OR =1.70, 95% CI 1.10 to 2.62, p=0.02]. REVIEWERS' CONCLUSIONS: There has been no research into the use of velnacrine as a cognitive enhancer in the treatment of Alzheimer's disease since 1994. The FDA peripheral and CNS drug advisory board voted unanimously against recommending approval. This review shows the toxic nature of velnacrine, and provides no evidence of efficacy. There are no grounds for further research into velnacrine.

Birks J, Flicker L. · Department of Clinical Geratology, University of Oxford, Oxford, UK, OX2 6HE. · Cochrane Database Syst Rev. · Pubmed #12535396 No free full text.

Abstract: BACKGROUND: Alzheimer's disease is the most common cause of dementia in older people accounting for some 60% of cases with late-onset cognitive deterioration. It is now thought that several neurotransmitter dysfunctions are involved from an early stage in the pathogenesis of Alzheimer's disease-associated cognitive decline. The efficacy of selegiline for symptoms of Alzheimer's disease remains controversial and is reflected by its low rate of prescription and the lack of approval by several regulatory authorities in Europe and elsewhere. Reasons for this uncertainty involve the modest overall effects observed in some trials, the lack of benefit observed in several trials, the use of cross-over designs which harbour methodological problems in a disease like dementia and the difficulty in interpreting results from trials when a variety of measurement scales are used to assess outcomes. OBJECTIVES: The objective of this review is to assess whether or not selegiline improves the well-being of patients with Alzheimer's disease. SEARCH STRATEGY: The Cochrane Dementia and Cognitive Impairment Group Register of Clinical Trials, was searched using the terms 'selegiline', 'l-deprenyl', "eldepryl" and "monamine oxidase inhibitor-B". MEDLINE, PsycLIT and EMBASE electronic databases were searched with the above terms in addition to using the group strategy (see group details) to limit the searches to randomised controlled trials. SELECTION CRITERIA: All unconfounded, double-blind, randomised controlled trials in which treatment with selegiline was administered for more than a day and compared to placebo in patients with dementia. DATA COLLECTION AND ANALYSIS: An individual patient data meta-analysis of selegiline, Wilcock 2002 provides much of the data that are available for this review. Seven studies provided individual patient data and this was pooled with summary statistics from the published papers of the other nine studies. Where possible, intention-to-treat data were used but usually the meta analyses were restricted to completers' data (data on people who completed the study). MAIN RESULTS: There are 17 included trials. There were very few significant treatment effects and these were all in favour of selegiline; cognition at 4-6 weeks and 8-17 weeks, and activities of daily living at 4-6 weeks. There is little evidence of adverse effects caused by selegiline, and few withdrew from trials, apart from the Sano trial. The analyses were conducted on data available. There was no attempt to correct for missing patients because there were so few and withdrawal was probably unconnected with treatment. All trials examined the cognitive effects of selegiline, and in addition 12 trials examined the behavioural and mood effects. The meta-analysis revealed benefits on memory function, shown by improvement in the memory tests from several cognitive tests (the Randt Memory Index from Agnoli 1990 and Agnoli 1992, the BSRT from Sunderland 1992, prose recall from Filip 1991, ADAS-cog from Lawlor 1997, the Wechsler Memory Scale from Loeb 1990 and Mangoni 1991, the Rey -AVL from Piccinin 1990, and the MMSE from Sano 1995, Tariot 1998, Filip 1991, Freedman 1996, Burke 1993 and Riekkinen 1993). The combined memory tests, and overall the combined cognitive tests, analysed using standardised mean differences, showed an improvement due to selegiline compared with placebo at 4-6 weeks (SMD 0.39, 95%CI 0.07 to 0.72, P = 0.02, random effects model ) and 8-17 weeks, ( SMD 0.44, 95%CI 0.04 to 0.84, P = 0.03, random effects model). The meta-analyses of emotional state show no treatment effects. Several studies assessed activities of daily living using several different scales, the GBS-motor function from Agnoli 1990, the NOSIE-daily living from Filip 1991, the BDS-daily living from Loeb 1990 and Mangoni 1991, the DS from Sano 1995 and PIADL from Tariot 1998. The combined tests, analysed using the standardised mean difference, showed an improvement due to selegiline at 4-6 weeks (SMD -0.27, 95% CIs -0.41 to -0.13, P = <.001). The global rating scales, the BDS used by Burke 1993 and Tariot 1998, and the GBS used by Agnoli 1990 and Agnoli 1992, and the GDS used by Freedman 1996 and the CGI by Filip 1991, analysed using standardised mean differences showed no effect of selegiline. A variety of adverse effects were recorded, but very few patients left a trial as a direct result. Four studies reported no side effects. Mangoni 1991 reported poor tolerability for 3 patients out of 68 on treatment and 1 out of 51 on placebo, resulting in dropouts. Small numbers found equally in both groups reported anxiety, agitation, dizziness, nausea and dyspepsia. Piccinin 1990 reported that selegiline was well tolerated with few adverse reactions (dizziness and orthostatic hypotension) and no resulting drop outs. Burke 1993 and Loeb 1990 both reported that selegiline was very well tolerated with no serious side effects. Sano 1995 reported 49 categories of adverse events but found no differences between the 4 arms of the factorial trial. Freedman 1996 reported unequal numbers of dropouts in the trial with 7 subjects withdrawing from the selegiline group and only 1 subject from the placebo group. The meta-analyses of the numbers suffering adverse effects, and of the numbers of withdrawals before the end of the trial show no difference between control and selegiline. REVIEWER'S CONCLUSIONS: Despite its initial promise, ie the potential neuroprotective properties, and its role in the treatment of Parkinson's disease sufferers, selegiline for Alzheimer's disease has proved disappointing. Although there is no evidence of a significant adverse event profile, there is also no evidence of a clinically meaningful benefit for Alzheimer's disease sufferers. This is true irrespective of the outcome measure evaluated, ie cognition, emotional state, activities of daily living, and global assessment, whether in the short, or longer term (up to 69 weeks), where this has been assessed. There would seem to be no justification, therefore, to use it in the treatment of people with Alzheimer's disease, nor for any further studies of its efficacy in Alzheimer's disease.

López-Arrieta JM, Birks J. · Hospital General Universitario Gregorio Marañón - Cantoblanco, Consejería de Sanidad. Comunidad de Madrid, Carretera de Colmenar km 14.500, Madrid, Spain. · Cochrane Database Syst Rev. · Pubmed #12137606 No free full text.

Abstract: BACKGROUND: Dementia is an age-associated syndrome most commonly due to Alzheimer's disease (AD) and/or cerebrovascular disease. Calcium has an important role in regulating brain functions. Calcium ions link membrane excitation to subsequent intracellular molecular responses. Age-associated changes in calcium homoeostasis have possible repercussions on higher cortical functions. Nimodipine is an isopropyl calcium channel blocker which readily crosses the blood-brain barrier. Its primary action is to reduce the number of open calcium channels in cell membranes, thus restricting influx of calcium ions into cells. The usefulness of nimodipine in patients with Alzheimer's disease and vascular dementia and unspecified dementia is still controversial. In spite of the uncertainties about its efficacy in dementia, nimodipine is currently frequently prescribed for cognitive impairment and dementia in several continental European countries. OBJECTIVES: To assess the clinical efficacy of nimodipine for the manifestations of dementia, in unclassified disease and in the major subtypes - Alzheimer's disease, cerebrovascular disease, and mixed Alzheimer's and cerebrovascular disease. SEARCH STRATEGY: The Cochrane Dementia and Cognitive Improvement Group's Specialized Register - which contains reports of trials from all major medical databases and many trial databases - was last searched on 3 August 2001 using the term 'nimodipin*'. SELECTION CRITERIA: All unconfounded, double-blind, randomized trials in which treatment with nimodipine was administered for more than a day and compared with placebo in patients with dementia, of unclassified type or attributable to Alzheimer's disease, cerebrovascular disease, or mixed Alzheimer's and cerebrovascular disease. DATA COLLECTION AND ANALYSIS: Data were extracted independently by the reviewers and the odds ratio (95%CI) or the average difference (95%CI) were estimated. Both intention-to-treat and on-treatment results were extracted. MAIN RESULTS: Fourteen trials were included which tested two treatment regimes, 90 and 180 mg/day of nimodipine for 12 and 24 weeks. Two trials included only patients with Alzheimer's disease (AD), 9 trials included only patients with cerebrovascular dementia (CVD), and three trials included patients with AD, CVD and mixed disease. Available outcome data from 9 trials (2492 patients) cover the domains of cognitive function, activities of daily living, global clinical state, safety and tolerability. By pooling available data from all trials, whatever the diagnosis of the patients included, this review found benefit associated with nimodipine (90 mg/day at 12 weeks) compared with placebo on the SCAG scale ( WMD -7.59, 95% CI -9.87 to -5.31, P<0.00001) on clinical global impression (WMD -0.87, 95% CI -1.07 to -0.67, P<0.00001) and cognitive function (SMD 0.61, 95% CI 0.42 to 0.81, P<0.00001) but not on scales assessing activities of daily living. When the AD trials and the VD trials were pooled separately similar significant results were found for the 90mg/day dose of nimodipine at 12 weeks. Drop-out rates were low in the trials, affecting similar proportions of treatment and placebo groups. Nimodipine is well tolerated with a low rate of adverse effects similar to that associated with placebo. There were slightly more adverse cerebrovascular events, and adverse events due to blood problems, associated with placebo than with nimodipine, and adverse autonomic events were slightly more common with nimodipine than with placebo. REVIEWER'S CONCLUSIONS: Nimodipine can be of some benefit in the treatment of patients with features of dementia due to unclassified disease or to Alzheimer's disease, cerebrovascular disease, or mixed Alzheimer's and cerebrovascular disease. It appears to be well tolerated with few side effects. Data were not available from several trials, a total of more than 500 patients. A meta-analysis of individual patient data from all trials is desirable. Dementia is a chronic disorder and the short-term benefits of nimodipine demonstrated in the trials reviewed do not justify its use as a long-term anti-dementia drug. New research must focus on longer term outcomes.

Coelho F, Birks J. · Departamento de Medicina Clinica, Universidade Federal do Ceara, Fortaleza, Ceara, Brazil. · Cochrane Database Syst Rev. · Pubmed #11405996 No free full text.

Abstract: BACKGROUND: The main pharmacological approach for the treatment of Alzheimer's disease (AD) has been based on the use of agents potentiating cholinergic transmission, particularly by inhibiting acetylcholinesterase (AChE), the enzyme that destroys acetylcholine after it has been secreted into the synaptic clefts. Physostigmine is an AChE inhibitor originally extracted from calabar beans. It is licensed in many countries as an agent for reversing the effect of drugs and poisons causing the anticholinergic syndrome. Studies conducted more than 20 years ago suggested that physostigmine could improve memory in people with or without dementia. Investigation of this property has been limited by the very short half-life of physostigmine. Various forms of administering the drug have been tried to overcome this problem, most recently a controlled-release (CR) oral formulation, and a skin patch. It has been proposed as a potential drug for the symptomatic treatment of AD. OBJECTIVES: To determine whether there is evidence of beneficial effects for the use of physostigmine in Alzheimer's disease. To assess the incidence and severity of adverse effects. SEARCH STRATEGY: The Cochrane Controlled Trials Register was searched using the following terms: 'physostigmine', 'physostigmine salicylate', 'Synapton' and 'Antilirium' in accordance with the Cochrane Dementia and Cognitive Improvement Group's search strategy. The pharmaceutical company was contacted. SELECTION CRITERIA: All relevant unconfounded, double-blind, randomized, placebo-controlled trials in which physostigmine was administered for more than one day to patients with dementia of Alzheimer type. Trials in which the allocation to the treatment was not randomized, or in which the allocation to the treatment was not concealed were excluded. DATA COLLECTION AND ANALYSIS: Data were extracted independently by two reviewers (JMC & JB), pooled where appropriate and possible, and the weighted or standardized mean differences or Peto odds ratios (95% CI) were estimated. Where possible, intention-to-treat analysis was used. MAIN RESULTS: Fifteen studies were included using four different methods of administration of physostigmine. Four studies, involving 29 people in total, used intravenous infusion; seven, involving 131 people, used a conventional oral form; four, involving 1456 participants, used a controlled-release oral form, and one study of 181 people used a verum skin patch. There are no usable results from the intravenous infusion trials, and the few results from the conventional oral form showed no benefit of physostigmine compared with placebo. The results from two of the four studies of the controlled-release physostigmine apply only to a group of patients identified as responders in a pre-randomization titration period. The best dose physostigmine (mean 25mg/day) was associated with a 1.75 point improvement on ADAS-Cog score (mean difference -1.75, 95% confidence interval -2.90, -0.60 on an intention-to-treat basis) and a 0.26 point improvement on the CGIC score (treated as a continuous scale) (mean difference -0.26, 95% confidence interval 0.06, 0.46 on an intention-to-treat basis) compared with placebo at 6 weeks. There were statistically significantly higher numbers of patients from the physostigmine group withdrawing from the trial (22/183 vs 2/183)(OR 5.92, 95% confidence limits 2.59, 13.54) and suffering at least one event of nausea, vomiting, diarhoea, anorexia, dizziness, stomach pain, flatulence or sweating compared with placebo at 6 weeks. The best dose physostigmine (mean 27mg/day) was associated with a 2.0 point improvement on ADAS-Cog score (mean difference -2.02, 95% confidence interval -3.59, -0.45 on an intention to treat basis) compared with placebo at 12 weeks. There were statistically significantly higher numbers of patients from the physostigmine group withdrawing from the trial due to adverse events (13/83 vs 5/93)(OR 3.05, 95% confidence limits 1.15, 8.07) and suffering at least one event of nausea, vomiting, diarhoea, anorexia, dizziness, stomach pain, tremor, asthenia or sweating compared with placebo at 12 weeks. When no attempt was made to identify responders and all relevant patients with Alzheimer's disease were randomized, fixed dose physostigmine (mean 33 mg/day) was associated with a statistically significantly higher number withdrawing (234/358 vs 31/117)(OR 4.82, 95% confidence limits 3.17, 7.33), withdrawing due to adverse events (196/358 vs 10/117) (OR 6.54, 95%confidence limits 4.29, 9.95) and suffering at least one event of nausea, vomiting, diarhoea, anorexia, dizziness, stomach pain, dyspepsia, sweating, asthenia, dyspnoea or abnormal dreaming compared with placebo at 24 weeks. The results from the study of the verum patch physostigmine show that the double dose (delivering mean dose 12mg/day) was associated with statistically significantly higher numbers suffering at least one adverse event of vomiting, nausea or abdominal cramps compared with placebo at 24 weeks, but placebo was associated with statistically significantly greater numbers of gastrointestinal complaints at 24 weeks compared with single-dose physostigmine. REVIEWERS' CONCLUSIONS: The evidence of effectiveness of physostigmine for the symptomatic treatment of Alzheimer's disease is limited. Even in a controlled release formulation designed to overcome the short half-life, physostigmine showed no convincing benefit and adverse effects remained common leading to a high rate of withdrawal.

López-Arrieta, Birks J. · Hospital de Cantoblanco, Consejería de Sanidad, Carretera de Colmenar km 14.500, Madrid, Madrid, SPAIN, 28049. · Cochrane Database Syst Rev. · Pubmed #11279679 No free full text.

Abstract: BACKGROUND: Dementia is an age-related condition in which Alzheimer's disease (AD) and cerebrovascular disease account for the bulk of cases. The role played by calcium in regulating brain functions is well known - the calcium ion links membrane excitation to subsequent intracellular enzymatic response. Change in calcium homeostasis is one important effect of aging with repercussions on higher cortical functions. Nimodipine is an isopropyl calcium channel blocker which can easily cross the blood brain barrier. Its primary action is to reduce the number of open channels, thus restricting influx of calcium ions into the cell. The usefulness of nimodipine in patients with Alzheimer's disease and vascular dementia and unspecified dementia is still controversial with mixed results. In spite of the uncertainties about its efficacy in dementia, nimodipine is currently a frequently prescribed drug for cognitive impairment and dementia in several European countries. This review will be conducted in two phases; the current review is based on evidence from published data only. The second phase will be based on individual-patient data analysed centrally and added to this review in due course. OBJECTIVES: To determine the clinical efficacy of nimodipine for the symptoms of dementia, either unclassified or according to the major subtypes - Alzheimer's disease, vascular, or mixed Alzheimer's and vascular dementia. SEARCH STRATEGY: The Cochrane Dementia Group Register of Clinical Trials was searched using the terms 'nimodipine' and 'isopropyl (2-methoxy-ethyl) 1,4-dihydro-2, 6-dimethyl-4-(3-nitrophenyl)-3, 5-pyridinedicarboxylate'. SELECTION CRITERIA: All unconfounded, double-blind, randomised trials in which treatment with nimodipine was administered for more than a day and compared to placebo in patients with dementia, either unclassified or according to the major subtypes - Alzheimer's disease, vascular, or mixed Alzheimer's and vascular dementia. DATA COLLECTION AND ANALYSIS: Data were extracted independently by the reviewers and the odds ratio (95%CI) or the average difference (95%CI) were estimated. Both intention-to-treat and on-treatment results were extracted. MAIN RESULTS: This review produced no clear results. Many of the data published were not capable of being sensibly pooled. The data were compatible with nimodipine producing improvement, no change or even harm for those with Alzheimer's disease, vascular dementia, or mixed Alzheimer's and vascular dementia. It was not possible to use many of the published results in a combined analysis. For measures of overall clinical improvement, the intention-to-treat analysis, based on one study only, failed to detect any difference between nimodipine and placebo (OR 0.53; 95%CI 0.25 - 1.13). An on-treatment analysis, based on one study only, produced a statistically significant difference in favour of nimodipine (SMD 4.4; 95%CI 3.9 - 5.0). For cognitive function, the effect of nimodipine was statistically significantly different from placebo for the Mini Mental State Examination score (0-30; high =good) (SMD 0.9; 95%CI 0.59 - 1.22) and there was a statistically significant effect in favour of treatment for the Wechsler Memory Scale (SMD 0.47; 95%CI 0.17 - 0.77). These analyses were based only on those who completed the study and not intention-to-treat analyses. There were no results presented in a form suitable for pooling for functional autonomy, behaviour, quality of life dependency (eg institutionalization), effect on carer, death, acceptability of treatment (as measured by withdrawal rate, safety (as measured by the incidence of adverse effects, including side effects, leading to withdrawal). REVIEWER'S CONCLUSIONS: This review provides no convincing evidence that nimodipine is a useful treatment for the symptoms of dementia, either unclassified or according to the major subtypes - Alzheimer's disease, vascular, or mixed Alzheimer's and vascular dementia. However, as so few of the trials presented data in a format suitable for pooling, the results of this review may be modified when further data from all relevant trials are included. There is an urgent need for the independent evaluation of the data already existing in the trials but not accessible through published or grouped data. An independent meta-analysis of the individual patient data is required. Nimodipine cannot be currently recommended in patients with dementia. The results and conclusions of this update are unaltered by further searching as the additional studies do not add any further valid/eligible data.

Tabet N, Birks J, Grimley Evans J. · Old Age Psychiatry, The Maudsley Hospital, Denmark Hill, London, UK, SE5 8AZ. · Cochrane Database Syst Rev. · Pubmed #11034775 No free full text.

Abstract: BACKGROUND: Vitamin E is a dietary compound that functions as an antioxidant scavenging toxic free radicals. Evidence that free radicals may contribute to the pathological processes in Alzheimer's disease has led to interest in the use of vitamin E in the treatment of this disorder. OBJECTIVES: To examine the effects of vitamin E treatment for people with Alzheimer's disease. SEARCH STRATEGY: The Cochrane Dementia Group Register of Clinical Trials was searched with the following terms: vitamin E, Alzheimer's disease, dementia, alpha-tocopherol, cognitive impairment, cognitive function and controlled trials. The latest search was carried out in July 2000. SELECTION CRITERIA: All unconfounded, double blind, randomized trials in which treatment with vitamin E at any dose was compared with placebo for patients with Alzheimer's disease. DATA COLLECTION AND ANALYSIS: Two reviewers independently applied the selection criteria an assessed study quality. One reviewer extracted and analysed the data. For each outcome measure data were sought on every patient randomized. Where such data were not available an analysis of patients who completed treatment was conducted. MAIN RESULTS: Only one study was identified which met the inclusion criteria (Sano 1997). The primary outcome used in this study of 341 participants was survival time to the first of 4 endpoints, death, institutionalisation, loss of 2 out of 3 basic activities of daily living, or severe dementia, defined as a global Clinical Dementia Rating of 3. The investigators reported the total numbers in each group who reached the primary endpoint within two years for participants completing the study ("completers"). There appeared to be some benefit from vitamin E with fewer participants reaching endpoint - 58% (45/77) of completers compared with 74% (58/78) - a Peto odds ratio of 0.49, 95% confidence interval 0.25 to 0.96. However, more participants taking vitamin E suffered a fall (12/77 compared with 4/78; odds ratio 3.07, 95% CI 1.09 to 8.62). It was not possible to interpret the reported results for specific endpoints or for secondary outcomes of cognition, dependence, behavioural disturbance and activities of daily living. REVIEWER'S CONCLUSIONS: There is insufficient evidence of efficacy of vitamin E in the treatment of people with with Alzheimer's disease. The one published trial of acceptable methodology (Sano 1997) was restricted to patients with moderate disease, and the published results are difficult to interpret. There is sufficient evidence of possible benefit to justify further studies. There was an excess of falls in the vitamin E group compared with placebo which requires further evaluation.

Birks J, Grimley Evans J, Iakovidou V, Tsolaki M. · Department of Clinical Geratology, University of Oxford, Oxford, UK, OX2 6HE. · Cochrane Database Syst Rev. · Pubmed #11034705 No free full text.

Abstract: BACKGROUND: Alzheimer's disease (AD) is the commonest cause of dementia affecting older people. One of the therapeutic strategies aimed at ameliorating the clinical manifestations of Alzheimer's disease is to enhance cholinergic neurotransmission in relevant parts of the brain by the use of cholinesterase inhibitors to delay the breakdown of acetylcholine released into synaptic clefts. Tacrine, the first of the cholinesterase inhibitors to undergo extensive trials for this purpose, was associated with significant adverse effects including hepatotoxicity. Several other cholinesterase inhibitors, including rivastigmine, with superior properties in terms of specificity of action and low risk of adverse effects, have now been introduced. Rivastigmine has received approval for use in 60 countries including all member States of the European Union and the USA. OBJECTIVES: To determine the clinical efficacy and safety of rivastigmine for patients with dementia of Alzheimer's type. SEARCH STRATEGY: The Cochrane Controlled Trials Register (April 2000) the Cochrane Dementia and Cognitive Improvement Group Register of Clinical Trials (July 2000), other electronic databases and other sources of reports were searched. SELECTION CRITERIA: All unconfounded, double-blind, randomized trials in which treatment with rivastigmine was administered to patients with dementia of the Alzheimer's type for more than two weeks and its effects compared with those of placebo in a parallel group of patients. DATA COLLECTION AND ANALYSIS: One reviewer (JSB) applied study selection criteria, assessed the quality of studies and extracted data. MAIN RESULTS: Seven trials, involving 3370 participants, were included. Use of rivastigmine in high doses was associated with statistically significant benefits on several measures. High-dose rivastigmine (6 to 12 mg daily) was associated with a 2.1 point improvement in cognitive function on the ADAS-Cog score compared with placebo (weighted mean difference -2.09, 95% confidence interval -2.65 to -1.54, on an intention-to-treat basis) and a 2.2 point improvment in activities of daily living assessed on the Progressive Deterioration Scale (weighted mean difference -2.15, 95% confidence interval -3.16 to -1.13, on an intention-to-treat basis) at 26 weeks. Fewer patients were graded as having severe dementia at 26 weeks (55% of patients taking rivastigmine compared with 59% on placebo; odds ratio 0.78, 95% confidence interval 0.64 to 0.94). At lower doses (4 mg daily or lower) differences were in the same direction but were statistically significant only for cognitive function. There were statistically significantly higher numbers of events of nausea, vomiting, diarrhoea, anorexia, headache, syncope, abdominal pain and dizziness among patients taking high-dose rivastigmine than among those taking placebo. There was some evidence that adverse events might be less common with more frequent, smaller doses of rivastigmine. REVIEWER'S CONCLUSIONS: Rivastigmine appears to be beneficial for people with mild to moderate Alzheimer's disease. In comparisons with placebo, improvements were seen in cognitive function, activities of daily living, and severity of dementia with daily doses of 6 to 12 mg. Adverse events were consistent with the cholinergic actions of the drug. Further resarch is desirable on dosage (frequency and quanitity) in a search for ways to minimize adverse effects. This review has not examined economic data.

Qizilbash N, Birks J, Lopez Arrieta J, Lewington S, Szeto S. · SmithKline Beecham, New Frontiers Science Park (South), Third Avenue, Harlow, Essex, UK, CM19 5AW. · Cochrane Database Syst Rev. · Pubmed #10908463 No free full text.

Abstract: OBJECTIVES: To determine the clinical efficacy of tacrine for the symptoms of Alzheimer's disease. SEARCH STRATEGY: The Cochrane Dementia Group Register of Clinical Trials was searched using the terms 'tacrine', 'tetrahydroaminoacridine' and 'THA' (see the Group's search strategy for full details). SELECTION CRITERIA: All unconfounded, double-blind, randomized trials in which treatment with tacrine was administered for more than a day and compared to placebo in patients with dementia of the Alzheimer's type. DATA COLLECTION AND ANALYSIS: Data were extracted independently by two reviewers, pooled if appropriate and possible, and the pooled odds ratios (95%CI) or the average differences (95%CI) were estimated. Where possible, intention-to-treat data were used. MAIN RESULTS: This review produced no clear results. The results were compatible with tacrine producing improvement, no change or even harm for those with Alzheimer's disease. It was not possible to use many of the published results in a combined analysis. For measures of overall clinical improvement, the intention-to-treat analyses failed to detect any difference between tacrine and placebo (OR 0.87; 95%CI 0. 61 - 1.23). Behavioural disturbance, as measured by the Alzheimer's Disease Assessment Scale-noncognitive, failed to detect any difference between tacrine and placebo (SMD -0.04; 95%CI -0.52 - 0. 43). For cognition function, the effect of tacrine was not statistically significantly different from placebo for the MiniMental State Examination score (0-30; high =good) (SMD 0.14; 95%CI -0.02 - 0.30) and was barely statistically significantly in favour of treatment for the Alzheimer's Disease Assessment Scale-cognitive scale (SMD -0.22; 95%CI -0.32 - -0.13). Adverse events were not reported in a systematic way in the different trials, making formal comparison difficult. Raised serum liver enzymes was the major reason for withdrawal. The odds ratio for withdrawal due to an adverse event was significantly different from one, the control group experienced fewer events (OR 5.7; 95%CI 4.1-7.9). Gastrointestinal side effects (diarrhoea, anorexia, dyspepsia and abdominal pain) were the other major cause of adverse events and for withdrawal, and the odds ratio for withdrawal was also significantly different from one in favour of the control group (OR 3.8; 95%CI 2. 8-5.1). No deaths were reported in any of the studies during the trial period, up to six months. REVIEWER'S CONCLUSIONS: This review provides no convincing evidence that tacrine is a useful treatment for the symptoms of Alzheimer's disease. However, as so few trials presented data in a format suitable for pooling, the results of this review may be modified when further data from all relevant trials are included. There is an urgent need for the independent evaluation of the data already existing in the trials but not accessible through published or grouped data. An independent meta-analysis of the individual-patient data is required. The results and conclusions of this update are unaltered by further searching as the additional studies do not add any further valid/eligible data.

Birks J, Iakovidou V, Tsolaki M. · Department of Geratology, University of Oxford, Oxford, UK, OX2 6HE. · Cochrane Database Syst Rev. · Pubmed #10796621 No free full text.

Abstract: BACKGROUND: Alzheimer's disease (AD) is the most common cause of dementia in the elderly. One of the most successful therapeutic strategies for Alzheimer's disease has been the use of acetylcholinesterase inhibitors to enhance surviving cholinergic neurotransmission by inhibiting breakdown of released acetylcholine. The first generation acetylcholinesterase inhibitors, such as tacrine, revealed major limitations to use including hepatotoxicity. Several second generation acetylcholinesterase inhibitors have now been introduced, including rivastigmine, which are believed to have superior proprieties. The mode of action and metabolism of rivastigmine suggest that it is unlikely to interact significantly with other medications. This is of particular relevance in elderly AD patients, the majority of whom are likely to be receiving concomitant medication. Large multi-centre trials have been completed in the USA, Canada, Europe and South Africa. Rivastigmine has received EU approval for use in all member states. It has approval in 30 countries but not the US. It is currently under review by the Food and Drug Administration, who requested additional analyses in 1998. OBJECTIVES: To determine the clinical efficacy and safety of rivastigmine for patients with dementia of the Alzheimer's type. SEARCH STRATEGY: The Cochrane Controlled Trials Register, the Dementia Group Register of Clinical Trials, other electronic databases and other sources of reports were searched using the terms ENA 713, EXELON, and rivastigmine in addition to the terms for controlled trials in dementia (see the Group's search strategy for full details). SELECTION CRITERIA: All unconfounded, double-blind, randomised trials in which treatment with rivastigmine was administered for more than one day and compared to placebo for patients with dementia of the Alzheimer's type. DATA COLLECTION AND ANALYSIS: Data were extracted by the reviewer (JSB) and entered into an appropriate meta-analysis. The data extracted were cross-checked by the second reviewer (VI). For each outcome measure, data were sought on every patient randomised. To allow an intention-to-treat analysis, the data were sought irrespective of compliance, whether or not the patient was subsequently deemed ineligible, or otherwise excluded from treatment or follow-up. If these data were not available, an analysis of data on patients who completed treatment was conducted. MAIN RESULTS: There are seven included trials. There are no published reports for two large phase III trials, B304 and B351, although they were completed more than 3 years ago. These are part of the Novartis ADENA programme and comprise 1379 (49%) out of 2803 phase III patients. It is unclear how missing data are replaced in ITT analyses, as reports from the ADENA programme provide no description of the use of this method. This has a profound effect on the results: if the method is substantially the same as LOCF, the benefits of treatment inferred from the analyses described in the publications as ITT, may be exaggerated. The meta-analysis reveals benefits on cognitive function as measured by ADAS-Cog test scores for the higher dose of rivastigmine compared to placebo at 26 weeks and for the lower dose. An additional analysis of ADAS-Cog dichotomised into those showing less than 4 points improvement and those showing 4 or more points improvement at 26 weeks shows benefit for cognitive function for the higher dose of rivastigmine compared to placebo and not for the lower dose. Global clinical state, dichotomised, counting those showing no change or decline, against those showing improvement shows benefit due to lower dose rivastigmine compared to placebo at 26 weeks and not for the higher dose. One trial reported results at 18 weeks and there are no significant differences between higher dose rivastigmine and placebo. One trial reported results at 13 weeks, and there are no significant differences between the 4 or 6 mg/d rivastigmine group and p

Birks J, Flicker L. · Department of Geratology, University of Oxford, Oxford, UK, OX2 6HE. · Cochrane Database Syst Rev. · Pubmed #10796544 No free full text.

Abstract: BACKGROUND: Alzheimer's disease is the most common cause of dementia in older people accounting for some 60% of cases with late-onset cognitive deterioration. It is now thought that several neurotransmitter dysfunctions are involved from an early stage in the pathogenesis of Alzheimer's disease-associated cognitive decline. The efficacy of selegiline for symptoms of Alzheimer's disease remains controversial and is reflected by its low rate of prescription and the lack of approval by several regulatory authorities in Europe and elsewhere. Reasons for this uncertainty involve the modest overall effects observed in some trials, the lack of benefit observed in several trials, the use of cross-over designs which harbour methodological problems in a disease like dementia and the difficulty in interpreting results from trials when a variety of measurement scales are used to assess outcomes. OBJECTIVES: The objective of this review is to assess whether or not selegiline improves the well-being of patients with Alzheimer's disease. SEARCH STRATEGY: The Cochrane Dementia and Cognitive Impairment Group Register of Clinical Trials, was searched using the terms 'selegiline', 'l-deprenyl', "eldepryl" and "monamine oxidase inhibitor-B". MEDLINE, PsycLIT and EMBASE electronic databases were searched with the above terms in addition to using the group strategy (see group details) to limit the searches to randomised controlled trials. SELECTION CRITERIA: All unconfounded, double-blind, randomised controlled trials in which treatment with selegiline was administered for more than a day and compared to placebo in patients with dementia. DATA COLLECTION AND ANALYSIS: Data were extracted independently by the reviewers (JSB & LF), pooled where appropriate and possible, and the weighted or standardised mean differences (95%CI) estimated. Where possible, intention-to-treat data were used but usually the meta analyses were restricted to completers' data (data on people who completed the study). MAIN RESULTS: There are 15 included trials. All trials examined the cognitive effects of selegiline, and in addition, 12 trials examined the behavioural and mood effects. The results of 8 trials suggested some beneficial effect of selegiline in the treatment of cognitive deficits and in 3 trials in the treatment of behaviour and mood. The meta-analysis revealed benefits on memory function as evidenced by improvement in the memory tests from several cognitive tests. Pooling the data for all cognitive tests suggested significant benefits in those subjects treated with selegiline as compared to controls. There were benefits in mood and behaviour as demonstrated by measurements on the Brief Psychiatric Rating Scale and the Dementia Mood Assessment Scale. The global rating scales showed no effect of selegiline. Unfortunately, the evidence using standardised global cognitive scales was extremely limited, for both the MMSE and ADAS-cog. A variety of adverse effects were recorded, but very few patients left a trial as a direct result of the intervention. REVIEWER'S CONCLUSIONS: Although the evidence for a beneficial effect of selegiline on patients with Alzheimer's disease is promising there is not yet enough evidence to recommend its use routinely in practice. The individual patient data review will yield further evidence on the effects of selegiline compared to control as would additional studies evaluating the use of selegiline for the endpoints of standardised cognitive scales, clinician impression of global change, dependency and caregiver quality of life.

Qizilbash N, Birks J, López-Arrieta J, Lewington S, Szeto S. · SmithKline Beecham, New Frontiers Science Park (South), Third Avenue, Harlow, UK, CM19 5AW. · Cochrane Database Syst Rev. · Pubmed #10796507 No free full text.

Abstract: BACKGROUND: Tacrine is one of the first drugs to be widely marketed for the loss of memory and intellectual decline in Alzheimer's disease. The alleged success of tacrine in the treatment of these symptoms has been heralded as confirmation of the cholinergic theory of Alzheimer's disease. However, the efficacy of tacrine for symptoms of dementia remains controversial. This is reflected by the low rate of prescription of tacrine in countries where it is approved and the lack of approval by several regulatory authorities in Europe and elsewhere. The uncertainty about the efficacy of tacrine is due to the difficulties in interpretation of the results from the clinical trials. The reasons for this are the small effects of tacrine compared to placebo for all outcomes; the high incidence of adverse events; the lack of benefit observed in several trials; the use of cross-over designs and their associated methodological problems in a disease like dementia; the use of different measurement scales to assess outcome in different trials; and the problem of high dropout rates. OBJECTIVES: To determine the clinical efficacy of tacrine for the symptoms of Alzheimer's disease. SEARCH STRATEGY: The Cochrane Dementia Group Register of Clinical Trials was searched using the terms 'tacrine', 'tetrahydroaminoacridine' and 'THA' (see the Group's search strategy for full details). SELECTION CRITERIA: All unconfounded, double-blind, randomized trials in which treatment with tacrine was administered for more than a day and compared to placebo in patients with dementia of the Alzheimer's type. DATA COLLECTION AND ANALYSIS: Data were extracted independently by two reviewers, pooled if appropriate and possible, and the pooled odds ratios (95%CI) or the average differences (95%CI) were estimated. Where possible, intention-to-treat data were used. MAIN RESULTS: This review produced no clear results. The results were compatible with tacrine producing improvement, no change or even harm for those with Alzheimer's disease. It was not possible to use many of the published results in a combined analysis. For measures of overall clinical improvement, the intention-to-treat analyses failed to detect any difference between tacrine and placebo (OR 0.87; 95%CI 0.61 - 1.23). Behavioural disturbance, as measured by the Alzheimer's Disease Assessment Scale-noncognitive, failed to detect any difference between tacrine and placebo (SMD -0.04; 95%CI -0.52 - 0.43). For cognition function, the effect of tacrine was not statistically significantly different from placebo for the MiniMental State Examination score (0-30; high =good) (SMD 0.14; 95%CI -0.02 - 0.30) and was barely statistically significantly in favour of treatment for the Alzheimer's Disease Assessment Scale-cognitive scale (SMD -0.22; 95%CI -0.32 - -0.13). Adverse events were not reported in a systematic way in the different trials, making formal comparison difficult. Raised serum liver enzymes was the major reason for withdrawal. The odds ratio for withdrawal due to an adverse event was significantly different from one, the control group experienced fewer events (OR 5.7; 95%CI 4.1-7.9). Gastrointestinal side effects (diarrhoea, anorexia, dyspepsia and abdominal pain) were the other major cause of adverse events and for withdrawal, and the odds ratio for withdrawal was also significantly different from one in favour of the control group (OR 3.8; 95%CI 2.8-5.1). No deaths were reported in any of the studies during the trial period, up to six months. REVIEWER'S CONCLUSIONS: This review provides no convincing evidence that tacrine is a useful treatment for the symptoms of Alzheimer's disease. However, as so few trials presented data in a format suitable for pooling, the results of this review may be modified when further data from all relevant trials are included. There is an urgent need for the independent evaluation of the data already existing in the trials but not accessible through published or grouped data. A

López-Arrieta JM, Birks J. · Hospital de Cantoblanco, Consejería de Sanidad, Carretera de Colmenar km 14.500, Madrid, Madrid, Spain, 28049. · Cochrane Database Syst Rev. · Pubmed #10796495 No free full text.

Abstract: BACKGROUND: Dementia is an age-related condition in which Alzheimer's disease (AD) and cerebrovascular disease account for the bulk of cases. The role played by calcium in regulating brain functions is well known - the calcium ion links membrane excitation to subsequent intracellular enzymatic response. Change in calcium homeostasis is one important effect of aging with repercussions on higher cortical functions. Nimodipine is an isopropyl calcium channel blocker which can easily cross the blood brain barrier. Its primary action is to reduce the number of open channels, thus restricting influx of calcium ions into the cell. The usefulness of nimodipine in patients with Alzheimer's disease and vascular dementia and unspecified dementia is still controversial with mixed results. In spite of the uncertainties about its efficacy in dementia, nimodipine is currently a frequently prescribed drug for cognitive impairment and dementia in several European countries. This review will be conducted in two phases; the current review is based on evidence from published data only. The second phase will be based on individual-patient data analysed centrally and added to this review in due course. OBJECTIVES: To determine the clinical efficacy of nimodipine for the symptoms of dementia, either unclassified or according to the major subtypes - Alzheimer's disease, vascular, or mixed Alzheimer's and vascular dementia. SEARCH STRATEGY: The Cochrane Dementia Group Register of Clinical Trials was searched using the terms 'nimodipine' and 'isopropyl (2-methoxy-ethyl) 1,4-dihydro-2, 6-dimethyl-4-(3-nitrophenyl)-3, 5-pyridinedicarboxylate'. SELECTION CRITERIA: All unconfounded, double-blind, randomised trials in which treatment with nimodipine was administered for more than a day and compared to placebo in patients with dementia, either unclassified or according to the major subtypes - Alzheimer's disease, vascular, or mixed Alzheimer's and vascular dementia. DATA COLLECTION AND ANALYSIS: Data were extracted independently by the reviewers and the odds ratio (95%CI) or the average difference (95%CI) were estimated. Both intention-to-treat and on-treatment results were extracted. MAIN RESULTS: This review produced no clear results. Many of the data published were not capable of being sensibly pooled. The data were compatible with nimodipine producing improvement, no change or even harm for those with Alzheimer's disease, vascular dementia, or mixed Alzheimer's and vascular dementia. It was not possible to use many of the published results in a combined analysis. For measures of overall clinical improvement, the intention-to-treat analysis, based on one study only, failed to detect any difference between nimodipine and placebo (OR 0.53; 95%CI 0.25 - 1.13). An on-treatment analysis, based on one study only, produced a statistically significant difference in favour of nimodipine (SMD 4.4; 95%CI 3.9 - 5.0). For cognitive function, the effect of nimodipine was statistically significantly different from placebo for the Mini Mental State Examination score (0-30; high =good) (SMD 0.9; 95%CI 0.59 - 1.22) and there was a statistically significant effect in favour of treatment for the Wechsler Memory Scale (SMD 0.47; 95%CI 0.17 - 0.77). These analyses were based only on those who completed the study and not intention-to-treat analyses. There were no results presented in a form suitable for pooling for functional autonomy, behaviour, quality of life dependency (eg institutionalization), effect on carer, death, acceptability of treatment (as measured by withdrawal rate, safety (as measured by the incidence of adverse effects, including side effects, leading to withdrawal). REVIEWER'S CONCLUSIONS: This review provides no convincing evidence that nimodipine is a useful treatment for the symptoms of dementia, either unclassified or according to the major subtypes - Alzheimer's disease, vascular, or mixed Alzheimer's and vascular dementia. (ABSTRACT TRUNCATED)

Ames D, Kaduszkiewicz H, van den Bussche H, Zimmermann T, Birks J, Ashby D. · Department of Psychiatry, University of Melbourne, Australia. · Int Psychogeriatr. · Pubmed #18252031 No free full text.

This publication has no abstract.

Wilcock GK, Birks J, Whitehead A, Evans SJ. · Department of Care of the Elderly, University of Bristol, UK. · Int J Geriatr Psychiatry. · Pubmed #11813282 No free full text.

Abstract: OBJECTIVE: To evaluate the effect of selegiline in the treatment of patients with Alzheimer's disease, in terms of cognitive performance, functional ability, emotional state (including behaviour and mood) and global response. Data Sources The Cochrane database of trials, Embase, Medline and Psychlit. Study Selection Unconfounded, double-blind, randomised trials of selegiline compared with placebo reported before 31 December 1998. Data Extraction The reviewers selected trials for inclusion. Individual patient data were sought, but when these could not be retrieved summary data were extracted from published papers. RESULTS: Of 27 identified trials, 14 met the inclusion criteria. Individual patient data were retrieved from eight trials on 821 patients. Summary data were extracted from five trials on 240 patients. No data were available from one trial on 12 patients, which was therefore excluded from the meta-analysis. Fixed and random effects meta-analyses were performed on standardised mean differences. For cognition there was a statistically significant difference between selegiline and placebo at 4-6 weeks and 8-17 weeks after randomisation (at 8-17 weeks: smd=0.45 [95% confidence interval 0.03 to 0.88]), but this disappeared at later assessments. The size of the treatment difference was considered unlikely to be of clinical importance. Although there was a statistically significant difference at 4-6 weeks for activities of daily living, this disappeared at later assessments (at 8-17 weeks: smd=0.33 [-0.33, 0.69]). There were no statistically significant differences or clinically relevant differences between selegiline and placebo in terms of emotional state or global response. CONCLUSION: Although there was some evidence of improvement with selegiline in the short term in cognition and activities of daily living, the magnitude of the effect did not reach clinical importance. There was no evidence of long term effects.

Birks J. · Cochrane Neurological Network. · Neuroepidemiology. · Pubmed #15677877 No free full text.

This publication has no abstract.