Time Required for Complete Recovery from Chronic Propranolol Therapy

Abstract

Propranolol could not be detected in samples of plasma and left atrium obtained from eight patients during coronary bypass surgery 36 to 48 hours after withdrawal from chronic therapy. The norepinephrine sensitivity of strips of left atria obtained from four similar patients was not different from that in six control patients who had not previously received propranolol. In three ambulant patients, serial estimates of the chronotropic and inotropic responses to isoproterenol were made at daily intervals during withdrawal from propranolol. Isoproterenol sensitivity became stable or returned to control levels within 48 hours. These findings were confirmed by experiments in the rat. A withdrawal time of 48 hours thus appears sufficient for complete recovery from the cardiac effects of propranolol and any possibly active metabolites, and coronary bypass surgery should present no additional hazard. (N Engl J Med 289:607–609, 1973)