Tacrine (tetrahydroaminoacridine; THA) and lecithin in senile dementia of the Alzheimer type: a multicentre trial. Groupe Français d'Etude de la Tetrahydroaminoacridine

Abstract

Objective: To see whether combined treatment with oral tacrine (tetrahydroaminoacridine; THA) and lecithin improves the symptoms of patients with Alzheimer's disease.

Design: Multicentre double blind, placebo controlled, random order crossover trial with individual determination of maximum tolerated dosage and four month follow up.

Setting: Outpatient departments at six university neurological centres.

Patients: 67 Outpatients (24 men, 43 women) aged 53-81 (mean 66 (SD 7.3)) selected according to the following criteria: probable Alzheimer's disease as defined by the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association; absence of mood disorder; mini mental state score lower than 26; availability of a close relative able to complete questionnaires; and informed consent of the patient or his or her closest relative, or both.

Interventions: Mean of 114 mg tacrine or placebo daily plus 1200 mg lecithin daily given in three divided doses for one four week active treatment period and one four week control period without washout at crossover.

Main outcome measures: Cognitive state as assessed by Folstein's mini mental state rating scale, behavioural state as assessed by the Stockton geriatric rating scale, and overall state as assessed with a visual analogue scale rated by both the relative and the physician.

Results: Compared with placebo tacrine did not improve either the mini mental state score (mean 14.9 (SD 7.3) v 14.8 (7.3)) or the Stockton geriatric score (28.2 (15.7) v 28.7 (17.8)), but a slight and statistically significant improvement occurred in the physician's score on the visual analogue scale (6.3 (10.2) v 11.6 (17.9)). Seven patients dropped out. Six patients were excluded because of acute hepatitis and one withdrew for personal reasons not related to treatment. Two other patients developed acute hepatitis at the end of the eight week crossover trial and another during the follow up study. Twenty patients complained of gastrointestinal side effects.

Conclusions: Neither short term nor long term treatment with oral tacrine at dosages lower than 125 mg/day improves the symptoms of Alzheimer's disease. Moreover, these dosages may induce hepatitis (nine of 67 patients in this series).