The effect of H2-receptor antagonist premedication on the duration of vecuronium-induced neuromuscular blockade in postpartum patients

The clinical duration of vecuronium was measured in two groups of postpartum patients undergoing elective tubal ligation. Ten patients received no premedication and ten others ranitidine 150 mg orally the morning of surgery. The mean duration of action of vecuronium was 57.2 +/- 9.9 min in the unmedicated patients and 54.0 +/- 12.9 min in the ranitidine treated patients. These values were significantly greater than the mean value for nonpregnant control patients (35.3 +/- 8.4 min) but indistinguishable from the mean value for cimetidine pretreated patients (63.0 +/- 17.6 min) reported previously. The combined results of the previous and present studies provide convincing evidence that the clinical duration of vecuronium-induced neuromuscular blockade is significantly longer in the postpartum patient and independent of cimetidine or ranitidine pretreatment.