Increased drug effect induced by surgery

1 A thyrotoxic patient receiving a constant dose of propranolol and digoxin developed marked bradycardia postoperatively. 2 Compared to preoperative levels there was a considerable rise post-operatively in both plasma propranolol and serum digoxin steady-state concentrations. 3 Surgery by effecting drug disposition and disease processes may significantly alter drug handling in the perioperative period.