Endocrine Abstracts

A 69-year-old man was referred to Endocrine clinic after presenting to his GP with dizziness, syncope, and fatigue. 0900 h cortisol was low at 39 nmol/l. The remainder of the anterior pituitary profile was unremarkable. He had been diagnosed with HIV in 1997 and was treated with highly active anti-retroviral therapy (truvada 1 OD, ritonavir 100 mg OD, and darunavir 800 mg OD) in addition to acyclovir 400 mg OD with control of his CD4 count and viral load. In addition, treating unexplained weight loss and intermittent anorexia he had been commenced on megesterol acetate 160 mg in 2011.

Hydrocortisone was started at a dose of 10/5/5 mg with resolution of his symptoms.

He was advised to stop megesterol, and was subsequently weaned off hydrocortisone. Repeat early morning cortisol was 201 nmol/l in November 2013 with no ongoing symptoms of hypoadrenalism. Short Synacthen testing was normal.

Owing to the cytochrome P450 enzyme inhibiting effect of some of the ritonavir-based anti-retrovirals, Cushing’s and hypoadrenalism have been noted in the use and withdrawal respectively of even inhaled steroids in HIV. Megesterol has some glucocorticoid action and there have been reports of secondary adrenal suppression in patients with disseminated malignancy and AIDS.

Hypoadrenalism has been noted after withdrawal of megesterol after prolonged use of years and assessing for this is advised on stopping protracted courses. This case demonstrates profound symptomatic adrenal suppression induced by lower doses of megesterol used only intermittently in conjunction with ritonavir. Owing to the potent enzyme inhibiting effect of ritonavir the possibility of hypoadreanlism should be kept in mind in patients stopping megesterol even with intermittent use at low doses.