Results 1 to 1 of 1

Thread: GENERAL GUIDELINES for Vetoryl (trilostane) Dosing & Monitoring with ACTH Stimulation

  1. #1
    Join Date
    Apr 2008

    Default GENERAL GUIDELINES for Vetoryl (trilostane) Dosing & Monitoring with ACTH Stimulation

    **** Note: Any posts offering to give away, barter, trade, or sell prescription medications will be removed immediately ****

    GUIDELINES for Vetoryl (trilostane) Dosing and Monitoring with ACTH Stimulation Test - Revised by Lulusmom 3/21/2021

    NOTE: 1) If your vet is utilizing the Pre-Vetoryl cortisol test to monitor treatment, please see links to Pre-Vetoryl cortisol flow charts at the bottom of this page.
    2) For dogs on Lysodren (mitotane) treatment, please refer to Lysodren Loading Instructions and Related Tips in this subforum.

    • The FDA approved dose for Vetoryl capsules is a range of 1 – 3 mg/lb (2.2 – 6.7 mg/kg). Always start with the lowest possible dose, based on weight and available capsule sizes. If the calculated dose falls between currently available strengths, round the dose down to a whole capsule. Available capsule sizes include 5 mg, 10 mg, 30 mg, 60 mg and 120 mg. If a particular dose is unavailable, an alternative is compounded trilostane purchased from a reputable compounding pharmacy, see the Cost Savings for Owners of Cushingoid Dogs.

    • FOR MEMBERS WITH LARGER DOGS, studies, as well as the vast amount of experience with Vetoryl acquired since FDA approval, clearly shows that many larger dogs over 44 lbs (20 kg) are quite sensitive to the drug, requiring much smaller Vetoryl (trilostane) doses. UC Davis, as well as other premier veterinary teaching institutions, have established their own much lower dosing protocol for their larger patients. If you have a larger dog, please see “Vetoryl (trilostane) – Larger Dogs Smaller Doses” link can be found at the bottom of the page. This is very important because most general practice vets are not aware of this critical development and unfortunately, Dechra has not revised their dosing recommendations for larger dogs as of this writing.

    • Dechra, the maker of Vetoryl, recommends starting with once daily Vetoryl capsules dosing in the morning with food as food increases absorption by up to three times. However, we do know that a good many of the renowned and well published endocrine specialists’ we administrators follow start their patients on twice daily dosing. The reason for this is that Vetoryl has a short half-life and therefore twice daily dosing provides much better control of cortisol throughout the day. If dosing once a day, Vetoryl MUST be given with a small or full meal in the morning for proper absorption. Dogs on twice daily dosing should have their daily meal split ˝ in a.m. and ˝ in p.m. NOTE: Dogs with concurrent diabetes mellitus and/or calcinosis cutis should be on twice daily dosing as control of both of these conditions is contingent upon continuous control of cortisol throughout the day.

    • Dechra recommends that the ACTH stimulation monitoring tests be performed between 4 and 6 hours after the morning dose given WITH FOOD. However, many internal medicine specialists and some very Cushing’s savvy general practice vets prefer to perform the test 2 to 4 hours after the morning dose. Vetoryl’s peak concentration is about 2 to 3 hours after dosing so it stands to reason that the results of a test done between 2 to 4 hours would give a better assessment of efficacy for a particular dose. Either of these timing intervals is fine but a vet needs to pick one and make sure each and every test is performed at the same time, every time. NEVER FAST YOUR DOG FOR THIS TEST as results will be invalid.

    • The 1st ACTH stimulation test should be done 10-14 days after starting treatment. This test is done to make sure cortisol has not dropped too low. A dosage increase is NOT RECOMMENDED and is very rarely done at this time as the cortisol is expected to drift downward over the next few weeks.

    • The 2nd ACTH stimulation test should be performed 30 days after starting treatment. It is at this point that necessary dosing adjustments be made if warranted.

    • If adjustment in dose is made, the ACTH stimulation test cycle should be started over at 10-14 days, then 30 days....

    • If NO dose adjustment is needed after 30 days, subsequent ACTH stimulation tests are recommended every three months thereafter. It is very important that vets adhere to this protocol as it is well known that Vetoryl can continue to lower cortisol in dogs on long term treatment. It is not only important that a vet assess the results of each ACTH stimulation test but it is equally important that they check previous results to determine if there is any downward trend that might warrant a reduction in dose.

    • An increase in dose should usually be no greater than 25%.

    • A positive response to a dose is interpreted as improvement in clinical signs and a post-ACTH stimulated cortisol concentration between 1.45-9.1 µg/dL (40–250 nmol/L); however, experience in this group shows that most dogs are best controlled in the 2.0–5.5 µg/dL (55–152 nmol/L) range.

    • Pet owners must be vigilant in watching for signs that cortisol is too low. Symptoms of low cortisol include but are not limited to vomiting, diarrhea, lethargy, poor/reduced appetite, weakness, collapse and tremoring. Should you observe one or more of these symptoms, STOP treatment and contact your veterinarian immediately. In the event your vet is closed, contact or go to your local emergency facility. Withholding Vetoryl or trilostane, whether a few days or several, will not be detrimental to your dog.

    If this is your first experience with a Cushing’s diagnosis, it is highly recommended you take some time to read “Living with Cushing’s Syndrome” and “Treat Their Hyperadrenocorticism”. These brochures were published by Dechra, the maker of Vetoryl, for pet owners so they can gain a better understanding of the disease and its treatment. Please see links below:

    Living With Cushing's Syndrome

    Treat Their Hyperadrenocorticism

    Pre-Vetoryl Cortisol - Flow chart reference ranges in nmol/l

    Pre-Vetoryl Cortisol - Flow chart reference ranges in ug/dl

    Vetoryl (trilostane) – Larger Dogs Smaller Doses
    Last edited by lulusmom; 04-02-2021 at 08:53 AM. Reason: Revised to reflect more comprehensive information

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts