Misoprostol

Generic Details

Generic Name

Misoprostol

Other Names

  • Cytotec

Drug Class

  • Prostaglandins

Chemical Formula

C22H38O5

Molecular Weight

382.54 g/mol

Mechanism of Action

  • Misoprostol is a synthetic prostaglandin E1 analog that binds to prostaglandin receptors on the surface of gastric parietal cells. It helps reduce gastric acid secretion, increase bicarbonate and mucus production, and maintain the mucosal barrier. Additionally, it induces uterine contractions.

Indications

  • Prevention and treatment of NSAID-induced gastric ulcers
  • Induction of labor
  • Medical abortion especially when used in combination with mifepristone

Common Dosage Forms

  • Tablet

Typical Dosage

  • 200 mcg orally 4 times a day for the prevention of NSAID-induced ulcers
  • 400-800 mcg vaginally for induction of labor
  • 600 mcg orally for medical abortion

Pediatric Dosage

  • Safety and efficacy not established in children

Geriatric Dosage

  • Dose adjustment may be needed in the elderly

Side Effects

  • Nausea
  • Diarrhea
  • Abdominal pain
  • Uterine cramps
  • Vaginal bleeding or spotting
  • Headache

Contraindications

  • Pregnancy (contraindicated for use for the induction of labor in women with a previous cesarean delivery or major uterine surgery)
  • Hypersensitivity to prostaglandins

Pregnancy Category

  • Category X: Contraindicated in pregnancy due to potential risks to the fetus

Lactation Safety

  • Limited data on excretion into breast milk, caution advised

Drug Interactions

  • Antacids may reduce the efficacy of misoprostol
  • Concurrent use with other uterotonic agents may increase the risk of uterine hyperstimulation

Overdose Symptoms

  • Symptoms of overdose may include diarrhea, abdominal pain, and uterine contractions

Antidote for Overdose

  • There is no specific antidote, and treatment is supportive

Storage Conditions

  • Store at room temperature away from moisture and heat

Pharmacokinetics

  • Absorption: Rapidly absorbed after oral administration
  • Distribution: Crosses the placenta and is excreted in breast milk
  • Metabolism: Undergoes rapid de-esterification to its active metabolite
  • Excretion: Primarily excreted in the urine

Precautions

  • Use with caution in patients with a history of inflammatory bowel disease or cardiovascular disease

Warnings

  • Misoprostol can cause miscarriage and uterine rupture if used during pregnancy