misoprostol

Contraindicated in:

Hypersensitivity to prostaglandins;
OB:
Should not be used to prevent NSAID-induced gastric injury in pregnancy due to potential for fetal harm or death
;
Lactation: Lactation.

Use Cautiously in:

Rep: Women of reproductive potential;
Pedi: Safety and effectiveness not established in children.

Exercise Extreme Caution in:

Late trimester pregnancy, previous cesarean section or uterine surgery, advanced gestational age, or ≥5 previous pregnancies (when used for cervical ripening or to induce abortion, may cause uterine rupture).

Adv. Reactions/Side Effects ⬆ ⬇

GI: abdominal pain, diarrhea, constipation, dyspepsia, flatulence, nausea, vomiting

GU: miscarriage, menstrual disorders

Neuro: headache

Interactions ⬆ ⬇

Drug-drug:

↑risk of diarrhea with magnesium-containing antacids.

Availability ⬆ ⬇

(Generic available)

Tablets: 100 mcg; 200 mcg
In combination with: diclofenac (Arthrotec). See Appendix [not included in this PDA edition].

Route/Dosage ⬆ ⬇

Prevention of NSAID-Induced Ulcers

PO (Adults ): 200 mcg four times daily with or after meals and at bedtime, or 400 mcg twice daily, with the last dose at bedtime. If intolerance occurs, may ↓ dose to 100 mcg 4 times daily.

Pregnancy Termination

PO (Adults ): 400 mcg single dose 2 days after mifepristone if abortion has not occurred.

Cervical Ripening and Labor Induction

Intravaginally(Adults ): 25 mcg (¼ of 100-mcg tablet); may repeat every 3–6 hr, if needed.

US Brand Names ⬆ ⬇

Action ⬆ ⬇

Acts as a prostaglandin analogue, decreasing gastric acid secretion (antisecretory effect) and increasing the production of protective mucus (cytoprotective effect).
Causes uterine contractions.

Therapeutic effects:

Prevention of gastric ulceration from NSAIDs.
With mifepristone, terminates pregnancy of less than 49 days.

Classifications ⬆ ⬇

Therapeutic Classification: antiulcer agents, cytoprotective agents, abortifacients

Pharmacologic Classification: prostaglandins

Pharmacokinetics ⬆ ⬇

Absorption: Well absorbed following oral administration.

Distribution: Unknown.

Protein Binding: 85%.

Metabolism/Excretion: Metabolized in liver to its active form (misoprostol acid); 80% excreted by the kidneys.

Half-Life: 20–40 min.

Time/Action Profile ⬆ ⬇

(effect on gastric acid secretion)

ROUTE	ONSET	PEAK	DURATION
PO	30 min	unknown	3–6 hr

Patient/Family Teaching ⬆ ⬇

Explain purpose and side effects of medication to patient. Advise patient to read Patient Information before starting therapy. Instruct patient to take medication as directed for the full course of therapy, even if feeling better. Take missed doses as soon as possible unless next dose is due within 2 hr; do not double doses.
Advise patient to notify health care provider of all Rx or OTC medications, vitamins, or herbal products being taken and to consult health care provider before taking other medications.
Advise patient not to share misoprostol with others, even if they have similar symptoms; may be dangerous.
Inform patient that diarrhea may occur. Health care provider should be notified if diarrhea persists for >1 wk. Also advise patient to report onset of black, tarry stools or severe abdominal pain.
Advise patient to avoid alcohol and foods that may cause an ↑ in GI irritation.
Rep:
Administration of misoprostol to women who are pregnant can cause spontaneous abortion, birth defects, premature birth, or uterine rupture. The risk of uterine rupture ↑ with advancing gestational age and with prior uterine surgery, including cesarean delivery. Women of reproductive potential must be informed of this effect through verbal and written information and must use contraception throughout therapy. Misoprostol should not be used by pregnant women to ↓ the risk of NSAID-induced ulcers. It also should not be used in women of reproductive potential to ↓ the risk of NSAID-induced ulcers unless the patient is at high risk of complications from gastric ulcers associated with use of NSAIDs or is at high risk of developing gastric ulceration. In these patients, misoprostol may be prescribed if the patient has had a negative serum pregnancy test within 2 wk prior to beginning therapy; is capable of complying with effective contraceptive measures; has received both oral and written warnings of the hazards of misoprostol, including the risk of possible contraception failure; and will begin misoprostol only on the 2nd or 3rd day of the next normal menstrual period. If pregnancy is suspected, the woman should stop taking misoprostol and immediately notify health care provider.

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Indications ⬇

Contraind./Precautions ⬆ ⬇