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Influence of pentobarbital on effect and plasma levels of alprenolol and 4‐hydroxy‐alprenolol
Author(s) -
Collste Per,
Seideman Peter,
Borg Karl-Olof,
Haglund Kjell,
Bahr Christer
Publication year - 1979
Publication title -
clinical pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.941
H-Index - 188
eISSN - 1532-6535
pISSN - 0009-9236
DOI - 10.1002/cpt1979254423
Subject(s) - alprenolol , pentobarbital , chemistry , pharmacology , medicine , receptor
Six healthy subjects were given placebo and a single oral 0.2‐gm dose of alprenolol (Aptin) before and after 0.1 gin 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.