Misoprostol

Major Uses

Misoprostol is a prostaglandin E1 analog that is most commonly used for treating and preventing gastric ulcers associated with NSAIDs. It is also known for being effective as an abortifacient, and for treating atopy or cyclosporine-induced nephrotoxicity.

Common Precautions

Misoprostol should be used cautiously in patients with sensitivity to prostaglandins or prostaglandin analogs, and patients suffering from cerebral or coronary vascular disease. It may also cause seizures in epileptic patients and cause hypertension.

The most common negative side effect associated with misoprostol is GI distress, symptoms of which include diarrhea, vomiting, abdominal pain, and flatulence. Female dogs may also experience uterine contractions and vaginal bleeding.

Misoprostol should not be used in animals with a known allergy or hypersensitivity to the drug. A veterinarian should be contacted immediately if an overdose is suspected, the symptoms of which include diarrhea, GI lesions, tremors, emesis, focal cardiac, hepatic or renal tubular necrosis, hypotension, and seizures.

Storage

Misoprostol should be kept at room temperature and stored in a tightly sealed, light resistant, childproof container. The drug has a shelf life of 18 months and should immediately be disposed of upon expiration.

Administration

When treating GI ulcers in dogs, a common dose of misoprostol is between 2-5 micrograms/kg every 8-12 hours, or four times a day. For terminating pregnancy in dogs, 1-3 micrograms/kg intravaginally once daily is typically used. 10 mg/kg twice daily on a strict schedule will treat pyometra/metritis in dogs. For horses, a common dose is 5 micrograms/kg every 8 hours. Should administration of a dose be forgotten, it should be given as soon as possible. If it is almost time for the next scheduled dose, the missed dose should be skipped and administration should continue according to schedule. Two doses should never be given at the same time.

Doses may vary in different species, when the drug is given by a different route or concurrently with other medications, and with regards to a patient's age, breed, and health status. A veterinarian's dosing instructions and/or those printed on the medication label should be followed closely.