IMPORTANCE: Agitation is common among patients with Alzheimer disease; safe, effective treatments are lacking. OBJECTIVE: To assess the efficacy, safety, and tolerability of dextromethorphan hydrobromide-quinidine sulfate for Alzheimer disease-related agitation. DESIGN, SETTING, AND PARTICIPANTS: Phase 2 randomized, multicenter, double-blind, placebo-controlled trial using a sequential parallel comparison design with 2 consecutive 5-week treatment stages conducted August […]