Comparison of the effects of nicardipine and nifedipine on isolated human myometrium.
The effects of nicardipine, a calcium-entry blocker which also has a potent phosphodiesterase inhibitory action, were investigated on isolated human term-pregnant and nonpregnant myometrium, and compared with those of nifedipine. Both drugs relaxed pregnant and nonpregnant myometrial preparations contracted by potassium (127 mM), and also reduced or abolished contractions occurring spontaneously, or induced by prostaglandin F2 alpha, oxytocin and vasopressin. However, the effect of nicardipine had a slower onset of action than that of nifedipine, and the drug was significantly more potent than nifedipine is at least as effective as nifedipine. If the differences between the drugs can be reproduced also in vivo, nicardipine offers an interesting alternative to nifedipine for inhibition of undesired uterine activity.
D000328:Adult; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D015237:Dinoprost; D005260:Female; D006801:Humans; D009215:Myometrium / Q000502:physiology*; D009529:Nicardipine; D009543:Nifedipine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D010121:Oxytocin / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D011247:Pregnancy; D011460:Prostaglandins F / Q000494:pharmacology; D013997:Time Factors; D014590:Uterine Contraction / Q000187:drug effects
D002121:Calcium Channel Blockers; D011460:Prostaglandins F; D010121:Oxytocin; D015237:Dinoprost; D009529:Nicardipine; D009543:Nifedipine; D011188:Potassium