Tacrine: a pharmacological approach to Alzheimer's disease

Overall, studies of the effect of tacrine on the cognitive symptoms of AD are inconclusive. Small (1992) gave some insight into this variability of results by stressing that different research methods can generate different outcomes. Small also pointed out that there is an inherent weakness in the Mini Mental State Examination (MMSE)--a tool used in most, if not all, AD studies. The MMSE is not sensitive to subtle and real changes in mental function. Regardless of the inconclusiveness of these studies, research must continue in order to tease out the variables contributing to clinically significant gains found in some studies. Anecdotal observations, combined with the previously summarized clinical trials, indicate that a subgroup of AD patients may hope to benefit from tacrine. At a geriatric clinic with which the author is associated, prospective patients and their families are told that tacrine helps about 10% to 20% of those who take it. Further, they are instructed that tacrine seems to be most helpful if given early in the disease process and that it is relatively expensive. Treatment with tacrine costs about $1,000 to $1,500 per year (Anderson, 1993). The maximum dose of tacrine is 120 mg per day, and there is a relatively high incidence of side effects. The most serious side effect of tacrine is liver toxicity, which occurs in up to 30% of the patients taking this drug. Elevations in serum aminotransferase levels occur with the same frequency and therefore must be closely monitored. Additionally, 20% of patients taking tacrine develop nausea and vomiting.(ABSTRACT TRUNCATED AT 250 WORDS)