Additive effect of theophylline on the cardiac response to isoproterenol.
Clin Pharmacol Ther
; 41(3): 289-96, 1987 Mar.
Article
em En
| MEDLINE
| ID: mdl-3816017
ABSTRACT
To ascertain the effect of theophylline on the cardiac chronotropic response to beta-adrenergic stimulation, isoproterenol dose-response curves in healthy young subjects were compared during saline and theophylline maintenance infusions. Each study was repeated 1 to 3 weeks later to evaluate reproducibility. Neither the dose of isoproterenol required to raise the heart rate by 25 bpm (2.32 +/- 0.81 vs. 1.55 +/- 0.46 micrograms on day 1 and 1.28 +/- 0.22 vs. 1.27 +/- 0.25 micrograms on day 2) nor the slopes of the dose-response curves were affected by theophylline. Higher heart rates were observed after isoproterenol bolus dosing during theophylline than during saline infusion because of additive chronotropic effects of theophylline and isoproterenol. Since theophylline does not interact in a synergistic fashion with isoproterenol, phosphodiesterase inhibition appears to be an unlikely mechanism of the chronotropic effect of methylxanthines at therapeutic concentrations.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Teofilina
/
Frequência Cardíaca
/
Isoproterenol
Limite:
Adult
/
Humans
/
Male
Idioma:
En
Ano de publicação:
1987
Tipo de documento:
Article