Increase Trilostane? New to this.

[Doggyw/Cushings]

Hi -

I've searched the forum and haven't been able to find an answer to this. I do apologize if I've missed it. I'm wondering if the dose of trilostane my dog is taking should be reduced. Here's the background:

Rufus
7 years old, miniature golden doodle
Weight 1 year ago = 24 pounds
Weight today = 37 pounds

Cushings Symptoms:
Insatiable hunger and weight gain with pot belly appearance
Thinning Hair
Panting
Muscle weakness (can’t jump up on bed anymore)
Lethargy
Thin, parchment-like skin on his belly
Recurrent skin infections (many over the last several years)
Hyperpigmentation of the skin
Increased thirst

For the last several years, the vet we were seeing diagnosed the skin infections as being from allergies. Dismissed my concerns about weight gain and that he has so many classic symptoms of Cushings. Even when the allergy testing came back negative! I finally took him to a specialist.

12/18/2015 Low Dose Dexamethasone Suppression Test:
Pre-Dex (Baseline): 3.9 micgrograms/dl (reference 1.0 – 6.0)
4 hour Post-Dex: 0.3
8 hour Post-Dex: 1.6
Consistent with pituitary source Cushings.

As of today (Feb 1st):
He was started 2.5 weeks ago on Trilostane 8 mg twice a day (0.5 mg/kg twice a day = ½ the usual recommended starting dose).
There has been no clinical improvement (and the vet agrees). In fact he seems even more hungry and has gained another pound.

ACTH Stim test on 1/30/2016:
Baseline: 2.5 micrograms/dl (reference 2 – 6)
Post-ACTH: 10 micrograms/dl

The vet today told me that we should leave the dose the same (even though it is half the recommended dose and he is still so symptomatic) and recheck in 2 weeks, because the baseline ACTH was on the lower end. The information I am seeing on Trilostane indicates you should to up if the post-ACTH level is greater than 9.1. I also see in places that you shouldn’t change the dose at 2 weeks unless the post-ACTH level is too low.

I certainly want to do what is right for Rufus, and I absolutely understand the risks of Addison’s and don’t want to induce it. I just worry about having to spend another $425 in 2 weeks only to have confirmed that the dose needs to be increased.

Thoughts?

[Harley PoMMom]

Hi and welcome to you and your boy!

Has a CBC/chemistry blood panel been done recently? If so, could you post all levels that are marked abnormal (high/low) and please include the reference ranges and normal reporting units....thanks! Was a thyroid issue ruled out?

I agree with your vet and I wouldn't increase his Trilostane dose until he has been taking it for a full month. On the forum we have seen that a dog's cortisol can continue to drift downward during the first 30 days of treatment, so a dose adjustment is not recommended at that 10-14 day window.

Acth stimulation tests...ARGH!!! They are so expensive and I was so happy to learn that there is a way to save money but only if you have a smaller dog. Your boy is small enough to save you money too. Most vets use a stimulating agent called Cortrosyn but we call it liquid gold because it's that little vial that dictates the cost. The vial is .25mg and instructions say to use entire vial but not all dogs need the entire vial. There have been studies done that show using just 5mcg per kg is all that's needed. Since there are 250mcg in one vial, your vet can get two stim tests out of one vial. This has saved members a lot of money, especially those with teeny dogs who can get five and six stims out of one vial. Formula for your boy's weight in pounds converted to kg is 37 divided by 2.2 = 16.81 x 5mcg = 84.09mcg. Your vet can round that off to half a vial or 125 mcg.

Some vets are not aware of this so we always provide the url to Dr. Mark Peterson's blog which instructs vets on how to dilute and store cortrosyn for future use.

http://endocrinevet.blogspot.com/201...rosyn-for.html

You have nothing to lose and everything to gain by printing this out or providing the URL to your vet and asking if s/he will please split the vial.

Hugs, Lori

[judymaggie]

Hi to you and Rufus! I wanted to give you the link to Dechra's technical brochure for Vetoryl:

http://www.dechrace.com/pdfs/vetoryl/VETORYLTechnicalBrochure.pdf

It has a lot of useful information, especially page 11 which is a flow chart showing timing of monitoring tests and suggested ranges.

You can find this brochure as well as a ton of other information in the "Helpful Resources" forum.

[molly muffin]

I just want to say hello and welcome to the forum. Lori and Judy have both imparted good information and links for you.

Check around and see if you can get the ACTH lower at another vet, then ask your vet to price match. This in addition to how to split the vial for multiple tests might help out with the cost.

[Doggyw/Cushings]

Thank you all for your thoughtful replies and supportive words. Rufus' thyroid, liver, CBC and electrolyte tests have all been normal.

I REALLY appreciate the tip about splitting the vial of trilostane to cut the cost. This journey has been and will no doubt continue to be an expensive one.

So we will recheck the ACTH next weekend and see where things are.


Thank you again.

[molly muffin]

Don't forget to give your vet the instructions on how to split the vial.

Also maybe call around, not all vets charge the same for the acth, so maybe if you find a lower one, your vet would price match?