Thiazide-induced hypokalaemia; prevalence higher in women

In 193 hypertensive patients taking bendrofluazide 5 mg daily, the mean serum potassium concentration was lower in women than in men (3.77 vs 3.99 mmol/l, P less than 0.001) and the prevalence of hypokalaemia (less than 3.5 mmol/l) was higher (25% vs 12%, P less than 0.05). This difference between the sexes was independent of age, body weight, renal function, the use of other antihypertensive drugs and compliance with treatment as judged by tablet counts. Severe hypokalaemia (less than 3.0 mmol/l) was uncommon and showed no difference between the sexes.