Does the route of administration of misoprostol make a difference? The uterotonic effect and side effects of misoprostol given by different routes after vaginal delivery

Objective: To compare the postpartum uterotonic effect and side effects of misoprostol administered by different routes. Study design: Fifty women were given misoprostol 400μg either by the oral solution, oral tablet, rectal or vaginal route, or intramuscular syntometrine 1ml after spontaneous vaginal delivery. Pre- and post-treatment uterine activity were measured with intrauterine pressure catheters. Results: Uterine activity produced by oral solution misoprostol 400μg was significantly higher than that of oral tablet, rectal and vaginal misoprostol (P=0.045, 0.004, 0.002, respectively). Onset of action after oral solution misoprostol was faster than by the oral tablet (P=0.01), rectal (P<0.001) and vaginal (P<0.001) routes. Shivering and pyrexia were most common with oral solution misoprostol. Maximum body temperature recorded was significantly higher with oral solution misoprostol than with oral tablet, rectal and vaginal misoprostol (P=0.005, 0.009, 0.001, respectively). Conclusion: Different routes of administering misoprostol greatly influence the effects achieved. Oral solution misoprostol produces the fastest and strongest uterotonic effect, with the most side effects.