Trilostane in Dogs

Abstract

SynopsisOver the last 10 years trilostane, a competitive inhibitor of steroid synthesis, has become widely used for the treatment of canine hyperadrenocorticism. Trilostane causes a significant but reversible decrease in cortisol production and a concomitant improvement in clinical signs in most dogs with this common condition. Side effects, though infrequent, can be serious: dogs treated with this drug require regular monitoring. This review summarises current knowledge of the use of this drug with particular emphasis on its efficacy, safety, adverse reactions and effects on endocrine parameters. Brief mention is made of its other uses in dogs and other species.

Pituitary-dependent hyperadrenocorticism in a shi tzu dog treated with twice-daily oral trilostane: a case report

“…Ectopic form of hyperadrenocorticism is rare in dogs. The remaining 15 to 20% of cases of spontaneous hypercortisolism are ACTH-independent and result from autonomous hypersecretion of glucocorticoids by an adrenocortical adenoma or adenocarcinoma (FELDMAN, 2011;HILL, 2011;RAMSEY, 2010).…”

“…Medical treatment aimed at the adrenal cortex (trilostane or mitotane) to lower plasma cortisol concentrations may increase ACTH secretion. The starting dose may range from 0.5 mg/kg twice daily to 20 mg/kg once daily, however, based on some studies seems to be logical to recommend a starting dose in the range 2 to 5 mg/kg once to twice daily (FELDMAN, 2011;HELM et al, 2011;MELIÁN, PÉREZ-ALENZA, PETERSON, 2010;RAMSEY, 2010).…”

“…A review consultation could adequate, and an ACTH stimulation test only performed if adverse effects have been noted. Monthly monitoring for the first three months, followed by monitoring every three months for the first year and every four to six months thereafter may well be adequate (RAMSEY, 2010). Considering this elucidations, he aim of this article is to report a case of a dog, seven years old, female, Shi Tzu, that presented with a pituitary-dependent hyperadrenocorticism, treated with twice-daily trilostane, orally, which the ACTH test is being performed in an unusual interval for monitoring (30 days interval).…”

“…HAC is relatively common in dogs, and 80 -85% of the cases are pituitary-dependent (FELDMAN, 2011;HILL, 2011;RAMSEY, 2010); Breed, body weight, clinical findings and abdominal ultrasound are aspects that require attention in the clinical approach for dogs presenting characteristics compatible with HAC, because they help to differentiate between PDH and ADH. Considering this, the patient presented here is prone to have PDH instead of ADH, mainly if we look forward to abdominal ultra-sound results which bilaterally mild adrenal increasing were observed.…”

“…The next step after changing the dose will be performing another ACTH stimulation test, respecting the thirty days interval. The reason for using this unusual interval is based on recommendation from Ramsey (2010); the respective author suggest a longer interval to evaluate the action of trilostane because he consider that performing an ACTH stimulation test ten to fourteen days after starting or changing therapy may not be so useful because changing the dose at this stage would risk increasing the dose too early.The treatment was instituted based on the recommendations for the starting dose that may range from 0.5 mg/kg twice-daily to 20 mg/ kg once daily. The response of the patient has been mild until now (± 50 days of treatment) and the dog showed decreasing in water and food intake, but no other improvement regard to the physical alterations described previously (bilaterally symmetrical alopecia, cutaneous calcinosis, pendulous abdomen and telangiectasia) were observed.…”