What are the pharmacokinetic properties and hemodynamic effects of carvedilol compared to labetalol in elderly male volunteers?
In elderly males, carvedilol demonstrates rapid oral absorption with ~45% bioavailability and hemodynamic effects (including blood pressure reduction and postural hypotension) comparable to labetalol.
This study in eight elderly male volunteers examined the pharmacokinetics of carvedilol following intravenous and oral administration of the drug. Blood pressure and pulse rate responses were also determined and compared with those to labetalol. Carvedilol was absorbed rapidly after oral administration with a bioavailability of approximately 45% and obeyed linear pharmacokinetics over the dose range 25-50 mg. The terminal elimination half-life varied between 5 and 14 h. Administration of the drug with food did not alter the bioavailability or kinetic handling of carvedilol. The hemodynamic responses to carvedilol followed the same pattern as those to labetalol. There was a rapid dose-related fall in blood pressure maximal after 4-5 h and disappearing by 12 hours. Tachycardia that was evident on placebo was inhibited by both drugs. Postural hypotension and dizziness were also apparent with both drugs.
Louis et al. (1987) studied this question.