Misoprostol

Oral
Gastric and duodenal ulcers, NSAID-associated ulceration

Oral
Termination of pregnancy (49 days or less duration)

Oral
Prophylaxis of NSAID-induced ulcers

Vaginal
Labour induction

Should be taken with food.

Pregnancy, including those not confirmed by ultrasound or biological tests, ectopic pregnancy, contraindication for mifepristone, pregnancy beyond 49 days of amenorrhoea. When labour has started; suspicion or evidence of foetal compromise prior to induction or uterine scar; uterine abnormality; placenta praevia or unexplained vag bleeding after 24 wk gestation; foetal malpresentation; signs/symptoms of chorioamnionitis (unless prior treatment has been instituted); before 36 wk gestation. Concurrent use of oxytoxic drugs or other labour induction agents.

Patients w/ conditions that predispose to diarrhoea (e.g. inflammatory bowel disease); CV disease; disease states where hypotension may precipitate severe complications (e.g. cerebrovascular disease, coronary artery disease or severe peripheral vascular disease including HTN). Patients in whom dehydration would be dangerous. Renal impairment. Lactation.

Diarrhoea, dyspepsia, flatulence, abdominal pain, nausea, vomiting, rashes, dizziness, headache, increased uterine contractility, abnormal vag bleeding. Rarely, hypotension.
Potentially Fatal: Toxic shock and septic shock following infections.

PO: X

Conduct pregnancy test in women of reproductive potential prior to therapy. Monitor uterine activity and foetal condition when used for labour induction.

Symptoms: Convulsions, sedation, tremor, dyspnoea, diarrhoea, abdominal pain, fever, palpitations, hypotension, bradycardia. Management: Supportive treatment.

Mg-containing antacids may aggravate misoprostol-induced diarrhoea.
Potentially Fatal: Increased uterotonic effects w/ oxytoxic drugs or other labour induction agents.

Description:
Mechanism of Action: Misoprostol is a synthetic prostaglandin E₁ analogue. It protects the GI mucosa by inhibiting basal, stimulated and nocturnal acid secretion and by reducing the volume of gastric secretions and increasing bicarbonate and mucus secretion. It also induces contractions of smooth muscle fibres of the myometrium and relaxation of the cervix uteri.
Pharmacokinetics:
Absorption: Rapidly and almost completely absorbed from the GI tract. Time to peak plasma concentration: Approx 15-30 min.
Distribution: Enters breast milk. Plasma protein binding: <90% (misoprostol acid).
Metabolism: Rapidly metabolised to misoprostol acid (active form) and further metabolised via oxidation in several body organs.
Excretion: Mainly via urine (80%). Elimination half-life: 20-40 min.

Source: National Center for Biotechnology Information. PubChem Database. Misoprostol, CID=5282381, https://pubchem.ncbi.nlm.nih.gov/compound/Misoprostol (accessed on Jan. 22, 2020)

Store at or below 25°C.

Antacids, Antireflux Agents & Antiulcerants / Drugs Acting on the Uterus

G02AD06 - misoprostol ; Belongs to the class of prostaglandins. Used as an oxytocic.
A02BB01 - misoprostol ; Belongs to the class of prostaglandins. Used in the treatment of peptic ulcer and gastro-oesophageal reflux disease (GERD).

Anon. Misoprostol. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 20/01/2016.

Buckingham R (ed). Misoprostol. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 20/01/2016.

McEvoy GK, Snow EK, Miller J et al (eds). Misoprostol. AHFS Drug Information (AHFS DI) [online]. American Society of Health-System Pharmacists (ASHP). https://www.medicinescomplete.com. Accessed 20/01/2016.

Misoprostol Tablet (GAVIS Pharmaceuticals, LLC). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 20/01/2016.