Tetrahydroaminoacridine in Alzheimer's disease

Tetrahydroaminoacridine (THA), a centrally acting anticholinesterase, was used in a two‐month, double‐blind, placebo‐controlled crossover trial to treat 10 patients meeting DSM‐III‐R criteria for dementia of the Alzheimer type. Eight patients continued to take THA for a further three months. Nausea was a frequent side‐effect. Five patients developed abnormal liver function tests; liver biopsies showed evidence of liver cell necrosis in three patients, a granulomatous reaction in one, and one recovered after reduction of THA dosage. During the trail, patients as a group showed a significantly better performance on one of 10 memory tests when taking THA as compared to placebo. One patient showed a marked clinical improvement, six showed some improvement, and three patients showed no improvement with the active treatment. The group of eight patients who completed a further three months of THA treatment showed a significant deterioration on two psychological test scores.