Clinical pharmacology of tetrahydroaminoacridine: a possible therapeutic agent Alzheimer's disease.

Tetrahydroaminoacridine (THA) was administered to a small number of patients with Alzheimer's disease. A minority of patients received the drug for longer than one week. Only one investigator [Summers et al. 1986] has reported dramatic palliative effects from the administration of THA. All investigators other than Summers reported side effects, especially troublesome is the frequent appearance of indications of hepatotoxicity. The efficacy and safety of THA are unknown. There is evidence that THA may have complex modes of action in addition to the inhibition of cholinesterases. There is a need for careful clinical assessment of THA and for further investigation of possible mechanisms of action.