On the pharmacokinetics of talinolol, a new beta 1-receptor blocking agent

In six female and male patients taking the specific beta 1-receptor blocking agent talinolol in daily maintenance doses between 100 and 300 mg, the plasma elimination half-life (t1/2) and the amount of excreted radioactivity via urine was evaluated after intake of a single dose of 14C-talinolol (0.88 MBq per 100 mg talinolol), and in the case of one patient with biliary fistula after intravenous injection (1.06 MBq per 10 mg talinolol). In this patient the bile concentration and elimination of radioactivity via bile was studied additionally. In the urine of three healthy volunteers, talinolol metabolites were isolated by TLC. In the six patients, 14C-talinolol was eliminated with a plasma t1/2 of 2.4 and 2.5 h, and a t1/2 of 4.6 via bile. The excretion of radioactivity amounted to 51.19% (intravenous injection), 23.9% (oral intake) in urine, and 7.49% in bile. In a urine fraction of one volunteer m-OH-talinolol was identified besides talinolol. The results indicate a remarkably high hepatic first-pass effect after oral administration of talinolol.