The pharmacokinetics of xamoterol in liver disease.

The pharmacokinetics of xamoterol, a beta 1-adrenoceptor partial agonist, have been studied in patients with liver disease and a group of age- and sex-matched normal controls. No significant differences were observed after the oral administration of xamoterol 200 mg. The low bioavailability of xamoterol was confirmed (6.1% in patients, 6.9% in controls). After i.v. xamoterol 0.2 mg kg-1, no significant differences between the groups were observed. A small increase in the terminal plasma elimination half-life (t1/2) was observed in patients when compared with controls (15.3 +/- 6.4 vs 8.4 +/- 2.8 h, mean +/- s.d., P = 0.08). Renal clearance accounted for about 50% of total clearance in patients and about 30% in controls. It is suggested that in patients with heart failure, hepatic dysfunction would probably not influence xamoterol disposition.