Effects of clorazepate on breathlessness and exercise tolerance in patients with chronic airflow obstruction.

Five patients with severe chronic lung disease were given placebo or 7.5 mg of clorazepate, a benzodiazepine, at bedtime for two weeks using a double-blind cross-over study design. Exercise tolerance, arterial blood gases, pulmonary function tests, self-rated breathlessness, and self-administered depression and anxiety scores were similar during drug treatment, placebo treatment, and washout periods. Higher doses of clorazepate were not tolerated by three of five patients. Nonanxious patients with chronic lung disease seem not to benefit subjectively or objectively from a low-dose benzodiazepine regimen.