Different conclusions about memantine

In the January issue of Canadian Family Physician, Dr Fadi Massoud was enthusiastic about the use of memantine in thetreatment ofmoderate to severeAlzheimer disease, calling it “effective and well tolerated.”1 In reaching this conclusion he cited 5 studies published between 1999 and 2004.2–6 Drug bulletins around the world and funding organizations in Canada and Australia looking at some or all of the same studies have reached markedly different conclusions than Dr Massoud has.

The Medical Letter noted that the drug “has been modestly effective in some US studies in improving performance.”7 The British Drug and Therapeutics Bulletin concluded that, at best, memantine produces only a small reduction in the rate of deterioration in global, functional, and cognitive scales among patients with moderately severe to severe disease.8 Moreover Drug and Therapeutics Bulletin could not find any evidence that treatment with memantine “reduces caregiver time and helps prevent institutionalization.” Prescrire International, the English-language translation of the French bulletin La revue Prescrire, said that data on the effects of memantine in patients with severe Alzheimer disease were sparse and weak. For moderately severe disease, Prescrire rated memantine a possible second-line option.9 The Therapeutics Letter published out of the University of British Columbia said that in advanced Alzheimer disease “memantine has not been demonstrated to improve outcomes of importance to patients and caregivers.”10

The Canadian Common Drug Review (CDR), which evaluates drugs for provincial and federal drug plans, did not recommend that the plans pay for memantine. Although 2 of 3 randomized controlled trials that the CDR assessed reported statistically significant improvements in activities of living and cognition, there was insufficient scientific evidence to establish the clinical importance of these small differences. A third trial found no significant benefit in functional, cognitive, behavioural, and global assessments.11 The Pharmaceutical Benefits Advisory Committee, which is Australia’s equivalent of the CDR, said that the government should not fund the drug because of uncertain clinical benefits and the resulting uncertain cost-effectiveness.12

In the face of these overwhelmingly negative opinions about memantine, it is hard to understand how Dr Massoud reached his conclusions. Finally, the article did not contain any statement about the presence or absence of any competing interests that Dr Massoud might have.

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