Pharmacokinetics of carteolol in patients with impaired renal function.

In order to determine the appropriate dosage of carteolol in renal dysfunction, the pharmacokinetics of carteolol has been examined in appropriate patients. The plasma concentrations and urinary excretion of carteolol were investigated in 15 patients with varying degrees of renal impairment during the administration of 5-20 mg carteolol hydrochloride (5 mg/tablet) for 2-45 months. Plasma carteolol levels were linearly correlated with the serum creatinine concentration (r = 0.87) and reciprocally with the creatinine clearance (r = 0.82). The urinary carteolol concentration was correlated with the urinary creatinine concentration (r = 0.69) and the urinary carteolol excretion was also correlated with the creatinine clearance (r = 0.79). These relationships become even closer when the plasma carteolol concentrations and urinary excretion rate of carteolol were factored by the administered tablets. The fractional renal excretion of carteolol was virtually constant at various degrees of renal function, and it always exceeded 100%, which indicates that carteolol was actively secreted, even in patients with renal failure. The estimated tubular secretion rate of carteolol was logarithmically correlated with the fractional renal excretion of carteolol (r = 0.93). The results indicate that the dose of carteolol should be determined according to the degree of renal impairment.