Mitotane

Major Uses

Mitotane is an adrenal cytotoxic agent that is most commonly used to treat pituitary-dependent hyperadrenocorticism in dogs and ferrets. It is also commonly used in palliative treatment of adrenal carcinoma. Mitotane is the preferred drug for these conditions, as its cytotoxic effects may affect adrenal tumor shrinkage.

Common Precautions

Mitotane should not be used in patients with concurrent diabetes mellitus, as rapidly changing insulin requirements may be required. Patients with renal or hepatic disease should be carefully monitored while using mitotane. There is a potential risk of acute endogenous steroid withdrawal while using this drug.

Possible negative side effects associated with mitotane include ataxia, lethargy, anorexia, weakness, vomiting, or diarrhea. While uncommon, neurologic side effects have also occurred with this drug. Some patients taking mitotane have suffered from liver changes such as congestion, centrolobular atrophy, and moderate to severe fatty degeneration.

Mitotane 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.

Storage

Mitotane should be kept at room temperature and stored in a tight, light resistant, childproof container. It should be kept out of reach from children and pets.

Administration

A typical dose of mitotane for treating hyperadrenocorticism in dogs is 25 mg/kg twice daily with food. For the treatment of adrenal carcinomas and adrenal adenomas, 50-75 mg/kg in daily divided doses for 10-14 days is typically effective. For treating hyperadrenocorticism in ferrets, a dose of 50 mg once daily for a week is normal. If a dose is forgotten, it should be administered as soon as possible. If it is almost time for the next scheduled dose, the missed dose should be skipped and the regularly scheduled dose should be administered. Two doses should not be administered at the same time, as overdose may occur.

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.