Naltrexone and Alzheimer's disease

Serby, Michael, Richard Resnick, Barbara Jordan, John Adler, June Corwin and John P. Rotrosen: Naltrexone in Alzheimer's disease. Prog. Neuro-Psychopharmacol. & Biol. Psychiat. 1986, 10 (3-5): 587-590. 1. 1. Naltrexone, an oral opiate antagonist, was administered to nine patients with a diagnosis of Alzheimer's-type dementia (ATD) in a two-phase design: (a) an open dose-ranging phase and (b) a double-blind placebo-controlled trial for patients who showed improvement during the open phase. 2. 2. After a three day placebo (baseline) period, patients received increasing doses of naltrexone over two weeks up to a maximum daily dose of 100 mg. Assessments were made at baseline and at daily dose of 5 mg, 50 mg and 100 mg. Testing was done 2 to 4 hours after medication was administered. Any patient who showed cognitive/behavioral improvement on a given dose of naltrexone was then treated with this dosage in a double-blind crossover comparison to placebo. Criteria for inclusion in the double-blind phase consisted of improvement on three behavioral scales and at least one cognitive test on a given dose of naltrexone. Each double-blind phase followed a one-week washout and was two weeks long. 3. 3. Two of the nine patients demonstrated apparent cognitive enhancement on 100 mg daily of naltrexone and were then tested in the double-blind crossover period. Only one of these patients improved during active naltrexone administration. 4. 4. We conclude that the opiate antagonist naltrexone in a dosage range of 5-100 mg daily is not efficacious in ATD.