RESUMO
OBJECTIVE: To compare the pharmacokinetic profiles of orally, rectally, and vaginally administered misoprostol tablets in pregnant women. METHODS: Women between 7 and 14 completed weeks of gestation were recruited and randomly assigned to be given 400 microg misoprostol orally, rectally, or vaginally 3 hours before surgical termination of pregnancy. Blood samples were obtained at 0, 7.5, 15, 30, 45, 60, 90, 120, and 240 minutes and later analyzed for plasma concentrations of misoprostol free acid (the principle metabolite). RESULTS: Vaginal misoprostol was present in the circulation longer than oral misoprostol and had a greater area under curve at 240 minutes (P <.001). Rectal misoprostol had a similar pattern but a much lower area under curve at 240 minutes. Oral misoprostol had a significantly greater peak plasma concentration and a shorter duration to maximum concentration than either rectal or vaginal misoprostol (both P <.001). CONCLUSION: Oral misoprostol tablet is also absorbed by the rectal and vaginal routes. Misoprostol administered in early pregnancy has route-dependent pharmacokinetics and is absorbed best when administered vaginally. LEVEL OF EVIDENCE: I