Your pet has been diagnosed with Cushing’s Syndrome (Hyperadrenocorticism), which arises from an excess of cortisol being produced by the adrenal gland (see additional handout, Cushing’s Syndrome). Our veterinarians are going to use a drug called Lysodren to help control the production of cortisol in your pet’s body. Lysodren works in the adrenal gland by destroying the cells that produce cortisol. Since the body needs cortisol, as well as the other hormones produced in the adrenal gland to survive, treatment with this drug can have serious side effects.

How does our veterinary team use Lysodren?

There are two stages to the use of this drug. Initially, we are going to have an “induction” phase during which you will give Lysodren twice daily for 4 to 10 days. During this time, our veterinarians are allowing the Lysodren to destroy all of the excess adrenal tissue that has built up in response to the continued stimulation by ACTH hormone. We know that as the Lysodren destroys enough of the adrenal tissue, your pet will probably start to lose his or her appetite. We will use this fact to help us determine when we have completed the induction phase. Therefore, we want you to follow these rules:

  • Feed your pet his/her normal feeding in the morning and afternoon before giving the lysodren.
  • If he or she eats the whole meal, give the pill(s).
  • As soon as he or she leaves 50% of his food, doesn’t eat, or takes much longer than normal to finish his meal, do not give the drug and call us. Most likely we will have you bring him or her in for an ACTH stimulation test to see if we have reduced the cortisol sufficiently to begin phase two of our treatment which is called maintenance.

Once our veterinarians have brought down the cortisol level to the normal range, we will give Lysodren only once a week at a different dose which we will inform you of.

What are the side effects of Lysodren administration?

Lysodren can cause a variety of side effects ranging from lack of appetite, to weakness, vomiting and diarrhea. Most of the side effects are actually due to the loss of cortisol caused by the lysodren. Therefore, we are going to dispense a bottle of Prednisone (a variety of cortisone) for you to have on hand as an antidote for these symptoms.

If your pet exhibits any of the symptoms above:

  • Do not give the next scheduled dose of lysodren.
  • Give the recommended Mg of Prednisone. Wait 1 hour, if the symptoms are not improving, call us.

What type of monitoring is needed while your pet is taking Lysodren?

Our veterinary team will need to perform an ACTH stimulation test at the end of the induction phase (5-10 days after starting the drug). Then again at 6 weeks, 3 months, 6 months and 1 year.

Because of the many potential problems arising from uncontrolled Cushing’s syndrome (diabetes, hypertension, strokes, skin problems, infections etc), we require a physical examination twice yearly, an ACTH Stimulation test and a general blood profile be run once yearly while your pet is taking Lysodren.

Please note that refills of this drug will not be provided without this monitoring for the sake of your pet’s medical safety.

What is the prognosis for treatment?

Lysodren has been used for years to successfully treat Cushing’s syndrome. The prognosis for treatment is quite good once we get your pet onto the maintenance dose. In most pets, the symptoms of Cushing’s syndrome will reduce within the first 4 to 6 weeks of treatment. Chronic skin problems should improve over the course of 3 to 6 months provided appropriate supportive care is given.