Endocrine Abstracts

A 71-year-old male ex-publican presented to the Medical Emergency Unit suffering from lethargy, weight loss, dizziness on standing and dyspnoea on exertion. He had a past medical history of hypertension, ischaemic heart disease and alcoholic liver disease and he admitted to drinking 100 units of beer per week. His anthihypertensive medications included lisinopril and hydrochlorthiazide. On examination BMI was 35 kg/m², blood pressure 85/65 mmHg and there was no buccal or palmar hyperpigmentation. Admission venous blood tests revealed glucose 2.8 mmol/l and sodium 113 mmol/l. This led to a working diagnosis of Addison’s disease. An MRI head, short synacthen test, ACTH and other baseline pituitary function tests were organised. MRI head revealed a structurally normal pituitary gland. The short synacthen test showed a low baseline cortisol of 109 nmol/l which rose to 510 nmol/l after 30 min. ACTH was 14 ng/l. All other tests were normal. Lisinopril and hydrochlorothiazide were stopped and he was commenced on i.v. hydrocortisone. This led to resolution of his hypotension and hyponatraemia. He was given a diagnosis of possible ACTH deficiency and discharged on replacement dose hydrocortisone to be followed up in the endocrine clinic. A repeat short synacthen test 3 months later showed a normal baseline cortisol of 513 nmol/l rising to 588 nmol/l after 30 min. Hydrocortisone therapy was stopped and hyponatraemia improved with changes to his antihypertensives and a reduced alcohol intake. The cause of the patient’s initial presentation was a combination of beer potomania and thiazide diuretic use. Beer potomania is an under-recognised condition characterised by hyponatraemia secondary to water intoxication. Recognition of this condition and careful fluid administration are required in the initial phase to avoid serious complications such as central pontine myelinolysis. Our case demonstrates that other causes of euvolaemic hypotonic hyponatraemia may obscure the actual diagnosis of beer potomania resulting in incorrect management.