Pindolol: A Pharmacokinetic Comparison with Other Beta-Adrenoceptor Blocking Agents

SummaryThe pharmacokinetic properties of the 9 most frequently studied beta-adrenoceptor blocking agents (alprenolol, atenolol, metoprolol, oxprenolol, pindolol, practolol, propranolol, sotalol and timolol) are compared. Some pharmacokinetic parameters were found to be similar or not relevantly different in this group of drugs, e.g. the rate and amount of absorption, distribution volume, elimination half-life, total clearance and total urinary excretion. However, some other pharmacokinetic parameters, such as daily dosage, oral bioavailability, first-pass effect and the ratio of renal versus hepatic clearance, were surprisingly different. A good correlation between systemic availability and urinary excretion of unchanged drug could be demonstrated for the beta-adrenoceptor blocking agents.The pharmacokinetic comparison shows that pindolol has some relevant advantages. Due to the moderate metabolism, a negligible first-pass effect results which yields a high oral bioavailability and leads to small inter-individual variations in plasma levels and drug effects. As a result of the balanced clearance by the liver and the kidney, and probably some compensating factors, no accumulation of pindolol has to be expected in patients with partial liver or kidney impairment. Therefore, apart from having the lowest daily dosage of the beta-blockers studied, administration of pindolol is less likely to be critical in patients with partial renal or hepatic insufficiency.