Comparison of venodilatory effect of amrinone and theophylline in human subjects.
Amrinone, a positive inotropic agent, is a selective phosphodiesterase III inhibitor and exerts vasodilatory effect on venous vessels. The present study was undertaken to compare the venodilatory effect of amrinone and theophylline, a nonselective phosphodiesterase inhibitor, in eight healthy male subjects. In a randomized crossover design, one of these drugs was infused into the dorsal hand vein preconstricted by phenylephrine and its diameter was measured using a linear variable differential transformer. The value of maximum vasodilation for amrinone (mean +/- standard deviation, 106% +/- 17%) was similar to that for theophylline (mean +/- standard deviation, 108% +/- 14%). However, the infusion rate of amrinone needed to induce 50% of maximum vasodilation was significantly less than that of theophylline (25 +/- 15 micrograms/minute vs. 192 +/- 87 micrograms/minute, respectively; P < 0.01). These findings suggest that the venodilatory activity of amrinone is more potent than that of theophylline in human subjects.
Harada
K
K
Department of Clinical Pharmacology, Jichi Medical School, Tochigi, Japan.
Ohashi
K
K
Kumagai
Y
Y
Fujimura
A
A
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000328:Adult; D000676:Amrinone / Q000494:pharmacology*; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D006225:Hand / Q000098:blood supply; D006801:Humans; D008297:Male; D010656:Phenylephrine / Q000494:pharmacology; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology*; D013806:Theophylline / Q000494:pharmacology*; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000494:pharmacology*; D014680:Veins / Q000187:drug effects
D000316:Adrenergic alpha-Agonists; D010726:Phosphodiesterase Inhibitors; D014665:Vasodilator Agents; D010656:Phenylephrine; D013806:Theophylline; D000676:Amrinone