Influence of pentobarbital on effect and plasma levels of alprenolol and 4-hydroxy-alprenolol.

Abstract

Six healthy subjects were given placebo and a single oral 0.2-gm dose of alprenolol (Aptin) before and after 0.1 gm pentobarbital at bedtime for 10 days. The plasma concentrations of alprenolol and its metabolite 4-hydroxy-alprenolol and the inhibition of exercise tachycardia were studied for 7 hr after the alprenolol. Alprenolol and 4-hydroxy-alprenolol plasma levels were decreased by about 40% by pentobarbital but plasma half-lives were unchanged. The inhibition of exercise tachycardia during a 7-hr period was reduced from 14.0% to 10.7% by pentobarbital. The reduction was proportional to the decreased drug plasma levels. There was a significant contribution of the metabolite to alprenolol effect. The estimation of relative potency of metabolite against parent compound was 0.9 before pentobarbital and 1.9 after pentobarbital.

• Authors: P Collste, P Seideman, K O Borg, K Haglund, C von Bahr
• Journal: Clinical pharmacology and therapeutics (Clin Pharmacol Ther) Vol. 25 Issue 4 Pg. 423-7 (Apr 1979) ISSN: 0009-9236 [Print] United States
• PMID: 428186 (Publication Type: Journal Article)

Chemical References

• Alprenolol
• Pentobarbital

Topics

• Adult
• Alprenolol (blood, pharmacology)
• Drug Interactions
• Heart Rate (drug effects)
• Humans
• Hydroxylation
• Male
• Pentobarbital (pharmacology)
• Physical Exertion
• Time Factors