鈥� 尾-Blocking drugs suppress plasma renin activity (PRA) promptly. The current study was undertaken to document the return of PRA once blockade is withdrawn. In addition, we have correlated the return of PRA with both fall in plasma propranolol levels and change in blood pressure (BP). Fourteen patients established a baseline PRA. Propranolol hydrochloride, 40 mg twice daily, was given for seven days and withdrawn abruptly. The PRA, plasma propranolol level, and BP were measured one and 12 hours after withdrawal, then every 24 hours. The PRA returns to baseline 12 hours after cessation of therapy. After withdrawal of therapy, there seems to be a "rebound" phenomenon in PRA, with elevations of 70% above baseline. This rebound also is demonstrated by a nonsignificant rise in BP. Plasma propranolol levels fall by 70% within 13 hours of withdrawal. The decrease in propranolol levels closely correlates with the rise in PRA.
(Arch Intern Med 140:1316-1318, 1980)