Trilostane

Trilostane In Dogs & Cats: Uses, Dosage and Side Effects

Overview

• Blocks adrenal synthesis of glucocorticoids.
• Effects on mineralocorticoids are relatively minor.

Uses of Trilostane

• Treatment of canine pituitary- and adrenal-dependent hyperadrenocorticism.
• Reportedly useful in the treatment of feline hyperadrenocorticism.
• Canine ‘alopecia X’ syndrome.

Dose of Trilostane in Dogs and Cats

Dogs:

• Hyperadrenocorticism: 2 mg/kg p.o. q24h or 1 mg/kg p.o. q12h.

Cats:

• Hyperadrenocorticism: 10–30 mg/cat p.o. q12–24h.

Side Effects of Trilostane in Dogs and Cats

• Reported adverse effects in dogs include mild GI signs, and mild increases in serum potassium, bilirubin and calcium.
• Clinical hypoadrenocorticism can be seen.
• Adrenal necrosis has been reported.
• Adrenal hyperplasia has been noted with prolonged treatment but the effects of this are unknown.
• Prolonged adrenal suppression after drug withdrawal has been noted in some cases.

Contraindications of Trilostane in Dogs and Cats

• Do not use in patients with renal or hepatic insufficiency.

Some Notes:

• Trilostane should not be administered concurrently with other drugs that suppress adrenal function, e.g. mitotane, and itraconazole.
• Treatment should be monitored after 10 days, 4 weeks, 12 weeks and then every 3–4 months using a combination of clinical signs and either an ACTH stimulation test (start test 3 hours post-dosing, aim for a post-ACTH cortisol of 40–120 nmol/l); or pre-pill cortisol measurement (aim for pre-pill cortisol of 40–140 nmol/l).
• Twice-daily dosing is advocated in those cases when clinical signs persist despite an increased once-daily dose or polydipsia appears within 24 hours or in patients with concurrent diabetes mellitus.
• Dosage adjustments may be necessary even after prolonged periods of stability.
• Trilostane should be given with food.