I'm not up to date with what's best/used for this sort of thing but I do know misoprostol is the drug that was used by Obstetricians in the 1990's which resulted in ruptured uteruses in VBAC women (they figured this out and stopped doing it by the end of the 1990's). There's simply not enough testing done in obstetric medicine.

I'm sure you've probably got this all sorted now but for anyone considering it, I would definitely do your research on this one before accepting this sort of drug. Google misoprostol / marsden wagner (ex director of the WHO's Maternal & Child Health) / uterine rupture.