Mitotane (o,p’-DDD)

Mitotane (o,p’-DDD) In Dogs & Cats: Uses, Dosage and Side Effects

Overview

• Induce Necrosis of the adrenal cortex To reduce the production of adrenal cortical hormones.

Uses of Mitotane (o,p’-DDD)

• Management of pituitary-dependent hyperadrenocorticism (HAC) in dogs.
• Other medications are authorized for this condition (see Trilostane).
• Has been used in the management of adrenal-dependent HAC, but with variable success.

Dose of Mitotane (o,p’-DDD) in Dogs and Cats

Dogs:

• 30–50 mg/kg p.o. (with/after food) q24h to effect (generally 3–10 days) then 50 mg/kg p.o. q7–14 days in 2–3 divided doses as required.
• Higher doses (50–150 mg/kg p.o. q24h) may become necessary for adrenal carcinomas.

Cats:

• Similar dose to dogs but efficacy in cats is very variable, with many showing no response at non-toxic levels.

Side Effects of Mitotane (o,p’-DDD) in Dogs and Cats

• Anorexia, vomiting, diarrhoea, and weakness usually follow a rapid plasma cortisol drop.
  Supplementing with steroids typically resolves them.
• Due to rapid pituitary tumour growth, neurological symptoms may appear 2–3 weeks after medication. So, Supplement glucocorticoids during this period of stress.
• Approximately 5% of dogs require permanent glucocorticoid and mineralocorticoid replacement therapy if given mitotane overdose.

Contraindications of Mitotane (o,p’-DDD) in Dogs and Cats

• No information is available.

Some Notes:

• Barbiturates and corticosteroids increase the hepatic metabolism of mitotane.
• There may be enhanced CNS depression with concurrent use of CNS depressants.
• Spironolactone blocks the action of mitotane.
• Diabetic animals may have rapidly changing insulin requirements during the early stages of therapy.