Tolerability of oral dextromethorphan in patients with a history of brain ischemia.

Twelve patients with a history of cerebral ischemia were randomized to treatment with the N-methyl-D-aspartate antagonist dextromethorphan (60 or 90 mg p.o. q.i.d.) or placebo for 2 weeks in a randomized, safety study. Neuropsychological testing did not detect evidence of cognitive dysfunction; however, side effects including lightheadedness, drowsiness, nausea, decreased coordination, and unsteady gait were reported by several patients while taking dextromethorphan.