Evaluation of tacrine hydrochloride (Cognex) in two parallel-group studies.

The efficacy of tacrine hydrochloride (Cognex) for the treatment of Alzheimer's disease (AD) has been confirmed in two randomized, double-blind, placebo-controlled, parallel-group studies. More than 1100 patients with mild to moderate, probable AD were randomized to receive placebo or tacrine for 12 or 30 weeks. Outcome measures included objective assessments of cognitive function, qualitative assessments of treatment response from the caregiver and clinician perspective, and assessments of activities of daily living. Statistically significant treatment effects favoring tacrine were demonstrated in each domain. These results suggest several considerations for clinicians. Because response to treatment is dose related, patients should be titrated to their maximum tolerated dose. Response may be subtle and may range from improvement to stabilization or slowed decline. A minimum treatment period of 6 months is recommended to evaluate a response and treatment should be continued depending on patient tolerability.