Trilostane: Everything About It!
Cushing’s disease in dogs is a complex condition that requires careful management.
One of the most prescribed medications for this disorder is trilostane.
But what exactly is trilostane, and how does it help dogs? In this in-depth guide, we’ll explore everything you need to know about trilostane, from its mechanism of action to its side effects and administration.
Whether you’re a concerned pet owner or a veterinary professional, this post aims to be your go-to resource for understanding trilostane and optimizing your dog’s health.
What Is Trilostane (Vetoryl)?
Trilostane API is a white to off-white crystalline powder marketed under Vetoryl for veterinary uses.
Trilostane is a synthetic steroid analog classified as a competitive inhibitor of 3-beta-hydroxysteroid dehydrogenase, an enzyme critical in producing steroid hormones.
Initially developed for human use, it’s now primarily employed in veterinary medicine to manage dogs’ hyperadrenocorticism (Cushing’s disease).
Unlike steroids, trilostane suppresses the adrenal glands’ overproduction of cortisol, a hormone linked to stress and metabolism.
Its veterinary-specific formulation ensures precise dosing for pets, making it a cornerstone treatment for Cushing’s
People used trilostane to treat Cushing’s syndrome in humans until the USFDA withdrew it from the USA in 1994.
It is mainly used for Cushing in dogs and cats (pituitary-dependent hyperadrenocorticism and adrenal-dependent hyperadrenocorticism).
People also use trilostane for breast cancer in the UK.
Some compounding pharmacies also compound it for dogs with the skin disorder Alopecia X.
Please note that it is not allowed to give pets trilostane with hepatic or renal diseases.
Avoid using it simultaneously with other drugs, such as mitotane and ketoconazole, that suppress adrenal activities.
What is Trilostane Used for in Dogs?
Trilostane is prescribed to treat canine Cushing’s disease, a condition where the adrenal glands overproduce cortisol. There are two types of Cushing’s:
Pituitary-Dependent (80-85% of cases): Caused by a benign pituitary tumor.
Adrenal-Dependent (15-20% of cases): Resulting from adrenal gland tumors.
Symptoms include excessive thirst, hair loss, panting, and a pot-bellied appearance. Trilostane alleviates these by normalizing cortisol levels, improving quality of life.
It’s not a cure but a long-term management tool.
Is Trilostane the Same as Vetoryl?
Yes, Vetoryl is the brand name for trilostane.
The terms are often used interchangeably, but there are differences:
Formulation: Vetoryl is specifically designed for dogs, ensuring consistent high quality. (5 USD per capsule, depending on strength.)
Generic Options: Compounded trilostane may be cheaper but varies in quality. (Often 30-50% cheaper but varies by pharmacy)
Always consult your vet before switching between brands or generics to ensure efficacy and safety.
Is Trilostane a Steroid?
Yes, It is.
As you can see from its chemical structure above, trilostane has a similar four-ring structure to a steroid.
It is an epoxy steroid, to be exact.
Is Trilostane a Chemotherapy Drug?
Trilostane is not chemotherapy.
While Cushing’s can stem from tumors, trilostane doesn’t target cancer cells.
Instead, it manages hormone levels.
Chemotherapy drugs like mitotane (Lysodren) destroy adrenal tissue, but trilostane offers a safer, reversible alternative by regulating enzyme activity.
Trilostane vs. Mitotane
Both trilostane and mitotane treat Cushing’s, but they differ significantly:
| Item | Trilostane | Mitotane |
|---|---|---|
| Mechanism | Enzyme inhibitor | Adrenal cytotoxic agent |
| Reversibility | Effects reversible | Permanent tissue damage |
| Safety | Lower risk of severe side effects | Higher risk of adrenal crisis |
| Dosing | Daily | The initial loading phase required |
Trilostane is often preferred for its safety profile, but mitotane may be better for adrenal tumors.
How Does Trilostane Work In Dogs?
Trilostane disrupts cortisol synthesis by inhibiting the enzyme 3-beta-hydroxysteroid dehydrogenase. Here’s a simplified breakdown:
Enzyme Blockade: The drug binds to the enzyme, preventing the conversion of pregnenolone to progesterone, a precursor to cortisol.
Cortisol Reduction: With reduced enzyme activity, cortisol production drops, easing Cushing’s symptoms.
Reversible Action: Unlike some treatments, trilostane’s effects are temporary and require daily dosing to maintain control.
This targeted approach minimizes damage to adrenal tissues, making it safer than older therapies.
Trilostane Dosage and Administration
Proper dosing is key to success:
Starting Dose: Typically 1-3 mg per pound of body weight, once daily.
Administration: Give with food to enhance absorption.
Monitoring: Vets perform ACTH tests 10-14 days post-treatment to assess cortisol levels.
Never adjust the dose without veterinary guidance. Sudden changes can trigger adrenal insufficiency or relapse.
How To Feed Trilostane To Dogs?
When our dogs or cats are sick and need to take trilostane for their suffering, how do we give it to them?
Due to the primary side effect of losing appetite, it is recommended that the capsule be stashed in their favorite foods.
However, do not give them too much; they may throw up later from being too full.
Try to give them the medication on a routine schedule, once daily, at the same time every day, and preferably in the morning with an empty stomach.
When you are tucking the branded capsules or compounded ones in, make sure you wear disposable gloves for protection.
If you do not have any gloves around, make sure you wash your hands thoroughly after handling them.
Take extra caution, especially if you plan to get pregnant.
Do not break a capsule to make up for proper dosing.
What Are The Side Effects Of Trilostane In Dogs?
Most dogs tolerate trilostane well, but side effects can occur:
Common: Lethargy, vomiting, diarrhea, or reduced appetite.
Serious: Acute hypoadrenocorticism (low cortisol), marked by weakness, dehydration, or collapse.
Risk factors include overdosing, concurrent illnesses, or pre-existing kidney/liver issues. Regular vet check-ups and ACTH stimulation tests are vital to monitor response and adjust doses.
Trilostane API Quality Standards
As you can see from our quality standards above, we have strict quality control over impurities.
Our single impurities are controlled under 0.5%, and total impurities are less than 1.0%.
Now check our correspondent testing results: 0.1% and 0.03%.
This should be the best quality in China.
Also, we keep our assay over 99% and make it as potent as possible.
How Much Does Trilostane API Cost?
If you are looking to import 99% trilostane for compounding for your dogs, cats, or horses, please check our offers below:
For 50 grams, our price is about 500 USD.
For 500 grams, our cost is around 2000 USD.
1kg our price is 3000usd for your ref.
Please note that our prices are subject to raw material fluctuations.
Since you have seen our prices, please check trilostane prices from other online suppliers now so you know where to buy them.
As you can see from the prices from other suppliers, the best offer for 200 mg is 190 USD.
The highest offer is from scbt, 1170 USD for 100mg.
You can contact us anytime if you need only several grams for research.
If you are a pharmacist looking for 99% powder for your compounding, we promise you the best price with the highest quality in Asia.
How To Store Trilostane API?
If you buy or import more powder than you can use for one compounding or production, you will need to store it for future use. How do you store it to keep it fresh as a new batch?
Below is how:
Pack your powder in an airtight, well-sealed foil bag that is protected from heat, moisture, and light.
If you have vacuum packing equipment, it can not be better with vacuum packing.
The shelf life for the pure powder is at least 2 years at a room temperature of 25°C.
If the temperature is too high, such as 35 or 40 degrees, it will have a shorter shelf life.
If stored in a freezer, its shelf life will be over 4 years.
No matter how long it has been stored, to ensure its quality and medical efficacy, retest its purity by HPLC and structure by 1HNMR before you plan to use it again during storage.
Though it is sensitive to temperature fluctuations, a small and mild change is allowed for its storage (20°C~30°C).
It will be fine if the temperature change is not dramatic.
Ensure it is not 30°C in one minute and 20°C in another.
If you only have a small quantity of powder, store it under -20°C in your refrigerator.
Seal it tightly to avoid any moisture.
Why was trilostane taken off the market For Humans?
Trilostane was taken off the market as a human medication in the 1990s because the researchers didn’t achieve the desired treatment effects. Still, people had been using it as a dog medication all along.
How long can a dog live on trilostane?
Dogs can live for 500~900 days if they are on trilostane medication for Cushing’s disease, and trilostane can keep them alive for as long as almost 3 years after they begin to suffer from Cushing’s disease.
- https://en.wikipedia.org/wiki/Trilostane
- https://pubchem.ncbi.nlm.nih.gov/compound/Trilostane
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5855282/
- https://www.drugs.com/vet/vetoryl-capsulestrilostane.html
- https://sitem.herts.ac.uk/aeru/vsdb/Reports/1891.htm
