Endocrine Abstracts

Megestrol Acetate (MA) is a synthetic progestogen used in the management of abnormal uterine bleeding, endometrial and breast carcinomas, and cancer-related cachexia. In addition to its progestogenic and appetite stimulating effects, MA has strong glucocorticoid receptor affinity. Case reports have described MA-induced hyperglycaemia and Cushing’s syndrome as well as hypothalamic-pituitary-adrenal (HPA) axis suppression and adrenal insufficiency. We report the case of a 51-year-old female living with obesity, who was admitted for an inpatient rehabilitation programme which includes a low-calorie diet component. Her background included stage; 1B endometrial carcinoma, managed with MA; 360 mg BD to control uterine bleeding, with planned hysterectomy following obesity management. Her inpatient stay was complicated by progressive fatigue, lethargy, presyncope and hypotension. Initial investigations revealed a morning cortisol of 26 nmol/l (reference range [RR] 166-507 nmol/l) and ACTH <3.0 ng/l (RR 7.2 – 63.3 ng/l). Serum sodium was 139 mmol/l (RR 133-146 mmol/l). A pituitary panel was otherwise normal. She had no history of steroid or other relevant medication use. She was commenced on hydrocortisone replacement (20 mg twice daily), with improvement in symptoms. In consultation with her gynaecology team, MA was discontinued and replaced with norethisterone 5 mg TDS. She was discharged on hydrocortisone 10 mg twice daily, with a plan for interval cortisol assessment in six weeks. This case highlights the risk of HPA axis suppression in patients receiving MA. Clinicians should consider adrenal insufficiency in symptomatic patients on MA particularly during physiological stress such as caloric restriction.