Plasma cortisol concentrations following cortisone infusion in dogs before and after treatment with cortisone acetate

To evaluate effects of iatrogenic hyperadrenocorticism on plasma cortisol concentrations produced by an infusion of hydrocortisone in dogs.

Plasma cortisol concentrations were measured regularly during a 6 h infusion of hydrocortisone sodium succinate at two dose rates. The infusions were performed before and after treatment for 30 d with oral cortisone acetate at 10 mg/kg/24 h, divided thrice daily. Adrenal activity during the experimental period was assessed by weekly ACTH stimulation tests.

Both infusion rates produced lower plasma cortisol concentrations after treatment for 30 d with cortisone.

Prior exposure to high concentrations of glucocorticoids may result in accelerated metabolism of glucocorticoids administered subsequently. This may necessitate increased dosages when using glucocorticoids to support inadequate adrenal function.