PetMD Editorial
By PetMD Editorial on Apr. 3, 2013

Drug Info

  • Common Name: Lysodren
  • Generics: No generics available
  • Drug Type: Adrenocortical cytotoxicant
  • Used For: Cushing’s disease and other types of cancer affecting adrenal glands
  • Species: Dogs
  • Administered: Tablets
  • How Dispensed: Prescription Only
  • Available Forms: 500mg
  • FDA Approved: Yes


Mitotane is used in the treatment of Cushing’s disease (hyperadrenocorticism) and related symptoms in dogs. 

Dosage and Administration

Always follow the dosage instructions from your veterinarian and any special instructions (e.g., give with food or give in the morning).

Please wear gloves when handling this medication. Wash hands well after handling.

When Mitotane is first prescribed it is usually given at high levels until it begins to take effect. Side effects may be seen during the initial dosing. Once it takes effect the dosing is usually reduced.

Missed Dose?

If a dose of Mitotane is missed, give it as soon as you remember. If you remember when it is almost time for the next dose, skip the one you missed and get back on your regular schedule. Do NOT double the dosing.

Possible Side Effects

Common side effects from Mitotane include: 

  • Lethargy
  • Weakness
  • Loss of appetite
  • Incoordination
  • Depression
  • Vomiting
  • Diarrhea

Some side effects could result in liver damage especially dogs with pre-existing liver conditions; signs of this include: 

  • Loss of appetite
  • Yellowing of gums, eyes or skin

Contact your veterinarian if you think your dog has any medical problems or side effects while taking Mitotane. Please be aware that other side effects may occur.


Do not administer to pets that are allergic to mitotane. If your pet has any allergic reactions to the medication please contact your veterinarian immediately.

Do not use in pregnant, or lactating dogs. Use caution when giving to pets that have liver or kidney disease.

Human Precautions: Pregnant women or women trying to get pregnant should not handle mitotane. Wear gloves when handling this medication and wash hands after handling. It can be toxic.


Store in a tight container in a dark area at room temperature, keep away from heat and direct sunlight. Additionally, as with any medication, keep out of children’s reach.

Drug Interactions

Consult your veterinarian when giving other medications or supplements with mitotane as interactions may occur. Please inform your vet if your dog is currently taking Spironolactone, prednisone, prednisolone, bartbiturates, warfarin and Phenobarbital, as interactions tend to occur when given with Mitotane.

Signs of Toxicity/Overdose

Overdose of mitotane may cause: 

  • Loss of appetite
  • Vomiting
  • Diarrhea
  • Weakness
  • Depression
  • Lethargy

If you suspect or know you dog has had an overdose, please contact your veterinarian or emergency vet clinic immediately.

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