Naltrexone and Alzheimer's disease

Area of Science:

• Neuroscience
• Pharmacology
• Gerontology

Background:

• Alzheimer's-type dementia (ATD) is a progressive neurodegenerative disorder.
• Current treatments for ATD have limited efficacy.
• Opiate antagonists are being explored for potential therapeutic effects in dementia.

Purpose of the Study:

• To investigate the efficacy of naltrexone, an oral opiate antagonist, in patients with Alzheimer's-type dementia (ATD).
• To determine the safety and cognitive/behavioral effects of naltrexone in ATD patients through a dose-ranging and placebo-controlled trial.

Main Methods:

• A two-phase study involving nine ATD patients: an open dose-ranging phase followed by a double-blind placebo-controlled trial.
• Patients received naltrexone doses from 5 mg to 100 mg daily, with assessments at various dose levels.
• Inclusion criteria for the double-blind phase required improvement in behavioral and cognitive tests during the open phase.

Main Results:

• Two out of nine patients showed apparent cognitive enhancement at 100 mg daily naltrexone during the open phase.
• Only one of these two patients demonstrated improvement during the subsequent double-blind crossover period with naltrexone.
• The study concluded that naltrexone (5-100 mg daily) was not efficacious in treating Alzheimer's-type dementia.

Conclusions:

• Naltrexone, an opiate antagonist, did not demonstrate significant efficacy in improving cognitive or behavioral symptoms in patients with Alzheimer's-type dementia.
• The findings suggest that naltrexone is not a viable therapeutic option for ATD at the tested dosages.
• Further research into opiate system modulation in ATD may be warranted, but naltrexone appears ineffective.