Misoprostol is a prostaglandin E1 analogue tablet that makes the uterus contract and protects the stomach lining. It is used in labour induction (with precautions), medical abortion, postpartum haemorrhage treatment and NSAID ulcer prevention.
Also known as: Cytotec, Gymiso
Oxytocin plus misoprostol for labour induction or pregnancy termination can cause uterine hyperstimulation, with risk of uterine rupture.
Both are potent uterotonics; the combination is not approved in the labels (Cytotec contraindicates combination with oxytocin/prostaglandins).
Contraction frequency and intensity, fetal distress, continuous uterine pain.
More than 5 contractions per 10 min, uterine pain between contractions, fetal heart decelerations.
Use only in specialised obstetric protocols with time-separated dosing and continuous monitoring of contractions and fetal status.
DailyMed — Cytotec (misoprostol) label, Warnings (contraindication with oxytocin/prostaglandins) and Pitocin (oxytocin): https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=52a82e45-afc5-47d0-a77f-a225609e2f6b
Taking with food and at bedtime reduces diarrhoea and abdominal pain, the dose-limiting adverse effects of misoprostol.
Take with meals and at bedtime (site monograph).
DailyMed — Cytotec (misoprostol): "administer with food and at bedtime"; site monograph.
Misoprostol is abortifacient — CONTRAINDICATED in pregnancy when used for gastroprotection.
Exclude pregnancy before prescribing as gastroprotectant; reliable contraception during NSAID + misoprostol therapy.
Prontuário Terapêutico INFARMED (misoprostol — abortifacient); site monograph (contraindicated in pregnancy).
Contraindicated in pregnancy: it is a prostaglandin E1 analogue with a potent abortifacient effect — which is precisely its registered use (induction of abortion and cervical ripening). In an ongoing pregnancy it causes uterine contractions, miscarriage, preterm birth and fetal malformations (Moebius syndrome described with 1st-trimester exposure).
Contraindicated in all trimesters. May only be used in the context of pregnancy termination or, at obstetric doses and under hospital supervision, for cervical ripening/induction of labour under strictly defined conditions.
No useful information available on excretion into breast milk (Prontuário, Annex 2); avoid, given the potential for uterine contractions and gastrointestinal effects in the infant.
Advise effective contraception immediately after administration; fertility may resume rapidly after pregnancy termination.
Prontuário Terapêutico INFARMED — Annex 1 (Drugs and Pregnancy): "Misoprostol: Contraindicated"; Annex 2: "No useful information available". EMC-UK (MHRA) — Misoprostol SmPC: https://www.medicines.org.uk/emc/product/5223/smpc
Clinical and educational support tool. The information does not replace a medical prescription or the opinion of a qualified healthcare professional.
PGE1 analogue with uterotonic and gastroprotective action; room-temperature stability and the vaginal/sublingual route made it the most far-reaching uterotonic in maternal health programmes where cold chain is limited.
Binds myometrial EP1/EP3 receptors: raised intracellular calcium and uterine contraction, plus cervical softening and dilation (collagen remodelling). In gastric mucosa, activates parietal-cell EP3 → reduced HCl secretion and increased mucus and bicarbonate flow (cytoprotective effect).
Oral: rapid absorption (peak 12–30 min), ~15% bioavailability of the active acid. Vaginal/sublingual: later peak (60–90 min) but 2–3-fold higher and prolonged maximum concentrations — the basis of obstetric preference.
Rapid ester hydrolysis (intestinal mucosa, liver, plasma) to misoprostol acid, the only active metabolite; no relevant CYP metabolism — minimal pharmacokinetic interactions.
Misoprostol acid: 20–40 min.
Medicines from the same therapeutic group (ATC classification) or the same pharmacological class.
