Za Pharmacy
Drugs, Supplies and Delivery
Misoprostol
Misoprostol is a synthetic prostaglandin E1 analogue with a wide range of clinical applications. It is primarily used for the prevention and treatment of gastric ulcers induced by nonsteroidal anti-inflammatory drugs (NSAIDs) and for obstetric and gynecological purposes, including medical abortion and labor induction. This article synthesizes information from the British National Formulary (BNF), Lippincott Textbook of Pharmacology, and Lange Basic & Clinical Pharmacology to provide a detailed overview of misoprostol, including its mechanism, uses, dosing, side effects, precautions, and drug interactions.
Misoprostol exerts its effects by:
- Gastric Protection:
- Stimulates mucus and bicarbonate secretion, enhancing the gastric mucosal barrier.
- Inhibits gastric acid secretion by acting on prostaglandin receptors in the stomach (Lippincott, Lange).
- Uterine Stimulation:
- Induces uterine contractions by binding to prostaglandin receptors in the myometrium, making it effective for obstetric and gynecological uses (BNF).
- Gastric Ulcer Prevention:
- Used to prevent NSAID-induced gastric ulcers in high-risk patients (BNF).
- Medical Abortion:
- Used in combination with mifepristone for early pregnancy termination (Lippincott).
- Labor Induction:
- Used to ripen the cervix and induce labor in pregnant women (Lange).
- Postpartum Hemorrhage (PPH) Prevention:
- Used to prevent excessive bleeding after childbirth (BNF).
- Gastric Ulcer Prevention:
- 200 mcg four times daily with food, or 400 mcg twice daily (BNF).
- Medical Abortion:
- 800 mcg vaginally or buccally 24–48 hours after mifepristone administration (Lippincott).
- Labor Induction:
- 25–50 mcg vaginally every 4–6 hours as needed (Lange).
- Postpartum Hemorrhage Prevention:
- 600 mcg orally or sublingually immediately after delivery (BNF).
Administration:
- For gastric protection, take with meals and at bedtime to minimize side effects.
- For obstetric uses, follow specific protocols for vaginal, buccal, or oral administration (Lippincott).
- Common: Diarrhea, abdominal pain, nausea, and vomiting (Lippincott).
- Serious:
- Uterine Hyperstimulation: Risk of uterine rupture during labor induction.
- Teratogenicity: Risk of fetal malformations if used during pregnancy (Lange).
- Pregnancy: Contraindicated in pregnant women unless used for labor induction or medical abortion (BNF).
- Allergy to Prostaglandins: Avoid in patients with known hypersensitivity (Lippincott).
- Cardiovascular Disease: Use with caution in patients with a history of cardiovascular disease due to risk of uterine hyperstimulation (Lange).
- NSAIDs: Misoprostol is often co-prescribed with NSAIDs to reduce gastric ulcer risk (BNF).
- Magnesium-Containing Antacids: May increase the risk of diarrhea (Lippincott).
- Oxytocin: Increased risk of uterine hyperstimulation when used concurrently (Lange).
Misoprostol is the generic name for this medication. It is marketed under the brand name Cytotec®. Generic versions are widely available and cost-effective
