title: Relaxing effects of Nifedipine on the nonpregnant human uterus in vitro and in vivo.
abstract: The effects of the calcium antagonist Nifedipine were investigated on isolated human myometrium and on uterine activity in healthy women during their first menstrual days. Nifedipine (0.01-1.0 microgram/ml) had a concentration-related inhibiting effect on spontaneous activity of the myometrial strips, and relaxed preparations contracted by potassium. In vivo, Nifedipine (20-30 mg) given orally, effectively and rapidly reduced uterine activity, decreasing both amplitude and frequency of uterine contractions, and reduced basal tone. A moderate increase in heart rate and a transient facial flushing were noted, but otherwise no side effects were observed. Calcium antagonists like Nifedipine represent a new approach to the problem of relaxing the myometrium, and might be an interesting therapeutic alternative in situations where inhibition of unwanted uterine activity is desirable.
mesh_terms: D000328:Adult; D005145:Face / Q000098:blood supply; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008598:Menstruation; D008875:Middle Aged; D009215:Myometrium / Q000187:drug effects; D009543:Nifedipine / Q000009:adverse effects / Q000494:pharmacology*; D011188:Potassium / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology*; D014590:Uterine Contraction / Q000187:drug effects; D014599:Uterus / Q000187:drug effects*
chemical_list: D011725:Pyridines; D009543:Nifedipine; D011188:Potassium