Pharmacologic approaches to cognitive deficits in Alzheimer's disease.

This article reviews placebo-controlled studies addressing drug efficacy for the cognitive deficits of Alzheimer's disease. Efforts to compensate for the presynaptic cholinergic deficiency in Alzheimer's disease by pharmacologically inhibiting acetylcholine degradation have been successful in several clinical trials. Two cholinesterase inhibitors are available for Alzheimer's disease, and others most likely will soon be available. Cholinesterase inhibitors represent the only therapy currently approved for the treatment of Alzheimer's disease. The antioxidant drugs alpha-tocopherol (vitamin E) and selegiline have been demonstrated marginally superior to placebo for slowing functional deterioration in patients with moderately advanced Alzheimer's disease. Epidemiologic studies suggest protective effects against Alzheimer's disease from postmenopausal estrogen replacement and nonsteroidal anti-inflammatory drugs. Placebo-controlled studies prospectively evaluating the hypotheses generated by these epidemiologic studies are ongoing.