2. B receptor antagonists 日21ADME u First-pass elimination u lower bioavailability: propranolol u Hepatic metabolism and renal excretion, hepatic and renal functions alter the effects of the drugs and result in large individual variation u Thus, dose individualization is necessary.2.1 ADME First-pass elimination, lower bioavailability: propranolol Hepatic metabolism and renal excretion, hepatic and renal functions alter the effects of the drugs and result in large individual variation Thus, dose individualization is necessary. 2.  receptor antagonists