Influence of smoking and age on pharmacokinetics of beta-receptor blockers

The influence of age and smoking on pharmacokinetics of pindolol and propranolol was investigated. Although there was a statistically significant difference in certain pharmacokinetic parameters (maximum plasma concentration, area under the curve, elimination constant and elimination half-life) between elderly patients (more that 60 years) and young persons (20-30 years) no significant differences were found as far as smoking and nonsmoking is concerned. This is in contrast with some reports in the literature. The higher plasma concentrations of both investigated drugs may be the result of a decreased metabolism of propranolol in older persons, in a decreased hepatic blood flow and a decreased renal elimination. Because of the lower sensitivity of beta-receptors in old persons, the higher plasma concentrations of beta-receptor blockers in this group of patients should not result in a diminished dose of the investigated beta-receptor blockers in the elderly.