Adrenocortical suppression in cats given megestrol acetate

Area of Science:

• Veterinary Pharmacology
• Endocrinology

Background:

• Megestrol acetate is a synthetic progestin used in veterinary medicine.
• Its effects on feline adrenal function and glucose metabolism require detailed investigation.

Purpose of the Study:

• To evaluate the impact of megestrol acetate on adrenocortical function in cats.
• To assess glucose tolerance in cats treated with megestrol acetate.

Main Methods:

• Oral administration of megestrol acetate (2.5 mg every other day or 5.0 mg daily) to cats for two weeks.
• Monitoring of ACTH-stimulated cortisol levels and glucose tolerance.
• Histopathological examination of adrenal glands.

Main Results:

• Both dosages of megestrol acetate caused significant impairment of adrenocortical function and morphological alterations.
• The most severe effects were noted one week after treatment cessation.
• One cat died due to megestrol acetate-induced adrenocortical suppression.
• Glucose tolerance testing was confounded by adverse effects of chemical restraint agents.

Conclusions:

• Megestrol acetate can lead to significant adrenocortical suppression in cats.
• Glucocorticoid supplementation should be considered for cats experiencing stress during or shortly after megestrol acetate treatment.
• Further research is needed to clarify glucose tolerance effects independent of restraint agents.