The starting dose for the
treatment of hyperadrenocorticism in dogs is 1.0-3.0 mg/lb (2.2-6.7
mg/kg) once a day based on body weight and capsule size.
VETORYL Capsules should be administered once daily in the morning with food. Giving with food will significantly increase the rate and extent of absorption of Vetoryl.
Weight range (pounds)
Weight range (kg)
Starting dose (mg) ONCE DAILY
10 to 22
4.5 to 10
22 to 44
10 to 20
44 to 88
20 to 40
120 (2 x 60 mg)
88 to 132
40 to 60
180 (3 x 60 mg)
Dogs over 132 pounds (60
kg) should be administered the appropriate combination of capsules.
After approximately 10-14
days at this dose, re-examine the dog and conduct a 4-6 hour post-dosing
ACTH stimulation test.
If physical examination is
acceptable, take action according to the following Table.
Action at 10-14 day evaluation
Post-ACTH serum cortisol
Re-start at a decreased dose
1.45 to 5.4
40 to 150
Continue on same
> 5.4 to 9.1
> 150 to 250
EITHER: Continue on current dose if clinical signs are well
OR: Increase dose if clinical signs of hyperadrenocorticism
are still evident*
Combinations of capsule
sizes should be used to slowly increase the once daily dose.
dose adjustments and close monitoring are essential. Re-examine and
conduct an ACTH stimulation test 10-14 days after every
dose alteration. Care must be taken during dose increases to monitor the
dog's clinical signs and serum electrolyte concentrations. Once daily
administration is recommended. However, if clinical signs are not
controlled for the full day, twice daily dosing may be needed using
combinations of capsule sizes to slowly increase the dose. For once
daily doses up to 90 mg, increase the total daily dose by 30 mg and
divide into 2 doses given 12 hours apart. For once daily doses ?120 mg,
increase the total daily dose by 60 mg and divide into 2 doses given 12
Once an optimum dose of
VETORYL Capsules has been reached, re-examine the dog at 30 days, 90
days and every 3 months thereafter. At a minimum, this monitoring should
include a thorough history and physical examination, ACTH stimulation
test (conducted 4-6 hours after
VETORYL Capsule administration), and serum biochemical tests (with
particular attention to electrolytes, renal and hepatic function). A
post-ACTH stimulation test resulting in a cortisol of < 1.45 µg/dL (< 40
nmol/L), with or without electrolyte abnormalities, may precede the
development of clinical signs of hypoadrenocorticism. Good control is
indicated by favorable clinical signs as well as post-ACTH serum
cortisol of 1.45-9.1 µg/dL (40-250 nmol/L).
If the ACTH stimulation
test is < 1.45 µg/dL (< 40 nmol/L) and/or if electrolyte imbalances
characteristic of hypoadrenocorticism (hyperkalemia and hyponatremia)
are found, VETORYL Capsules should be temporarily discontinued until
recurrence of clinical signs consistent with hyperadrenocorticism and
test results return to normal (1.45-9.1 µg/dL or 40-250 nmol/L). VETORYL
Capsules may then be re-introduced at a lower dose.
Owners should be
instructed to stop therapy and contact their veterinarian immediately in
the event of adverse reactions or unusual developments.
Federal (USA) law restricts
this drug to use by or on the order of a licensed veterinarian
The use of VETORYL
Capsules is contraindicated in dogs that have demonstrated
hypersensitivity to trilostane.
Do not use VETORYL
Capsules in animals with primary hepatic disease or renal insufficiency.
Do not use in pregnant
dogs. Studies conducted with trilostane in laboratory animals have shown
teratogenic effects and early pregnancy loss.
In case of overdosage,
symptomatic treatment of hypoadrenocorticism with corticosteroids,
mineralocorticoids and intravenous fluids may be required.
enzyme (ACE) inhibitors should be used with caution with VETORYL
Capsules, as both drugs have aldosterone-lowering effects which may be
additive, impairing the patient's ability to maintain normal
electrolytes, blood volume and renal perfusion. Potassium sparing
diuretics (e.g. spironolactone) should not be used with VETORYL Capsules
as both drugs have the potential to inhibit aldosterone, increasing the
likelihood of hyperkalemia.
Keep out of reach of
children. Not for human use.
Wash hands after use. Do
not empty capsule contents and do not attempt to divide the capsules. Do
not handle the capsules if pregnant or if trying to conceive. Trilostane
is associated with teratogenic effects and early pregnancy loss in
laboratory animals. In the event of accidental ingestion/overdose, seek
medical advice immediately and take the labeled container with you.
develop at any dose of VETORYL Capsules. In some cases, it may take
months for adrenal function to return and some dogs never regain
adequate adrenal function.
A small percentage of dogs
may develop corticosteroid withdrawal syndrome within 10 days of
starting treatment. This phenomenon results from acute withdrawal of
circulating glucocorticoids; clinical signs include weakness, lethargy,
anorexia, and weight loss1. These
clinical signs should be differentiated from an early hypoadrenocortical
crisis by measurement of serum electrolyte concentrations and
performance of an ACTH stimulation test. Corticosteroid withdrawal
syndrome should respond to cessation of VETORYL Capsules (duration of
discontinuation based on the severity of the clinical signs) and
restarting at a lower dose.
Mitotane treatment will reduce adrenal function. Experience in foreign markets
suggests that when mitotane therapy is stopped, an interval of at least
one month should elapse before the introduction of VETORYL Capsules. It
is important to wait for both the recurrence of clinical signs
consistent with hyperadrenocorticism, and a post-ACTH cortisol level of
> 9.1 µg/dL (> 250 nmol/L) before treatment with VETORYL Capsules is
initiated. Close monitoring of adrenal function is advised, as dogs
previously treated with mitotane may be more responsive to the effects
of VETORYL Capsules.
The use of VETORYL
Capsules will not affect the adrenal tumor itself. Adrenalectomy should
be considered as an option for cases that are good surgical candidates.
The safe use of this drug
has not been evaluated in lactating dogs and males intended for
The most common adverse
reactions reported are poor/reduced appetite, vomiting,
lethargy/dullness, diarrhea, and weakness. Occasionally, more serious
reactions, including severe depression, hemorrhagic diarrhea, collapse,
hypoadrenocortical crisis or adrenal necrosis/rupture may occur, and may
result in death.
Dog Owners should be aware
that the most common adverse reactions may include: an unexpected
decrease in appetite, vomiting, diarrhea, or lethargy and should receive
the Client Information Sheet with the prescription. Owners should be
informed that control of hyperadrenocorticism should result in
resolution of polyphagia, polyuria and polydipsia.
Serious adverse reactions associated with this drug can occur without
warning and in rare situations result in death.
Owners should be advised to discontinue VETORYL Capsules and contact
their veterinarian immediately if signs of intolerance are observed.
Owners should be advised of the importance of periodic follow-up for all
dogs during administration of VETORYL Capsules.
Storage: Store at controlled room
temperature 25°C (77°F) with excursions between 15°-30°C (59°-86°F)
How Supplied: VETORYL Capsules are
available in 10, 30, 60 and 120 mg strengths, packaged in aluminum foil blister
cards of 10 capsules, with 3 cards per carton.
Dechra Veterinary Products