The effect of oral potassium supplements on plasma potassium in normokalaemic and hypokalaemic patients.

Thirteen out of 44 patients taking bendrofluazide 10 mg daily became hypokalaemic over a period of three months. Oral potassium supplements of 3.6 grams daily (48 mmol) given in addition to bendrofluazide for a further period of 3 months raised plasma potassium level significantly in hypokalaemic patients only. We conclude that where patients on diuretic therapy are followed up with plasma potassium measurements, it is generally necessary to prescribe oral potassium in the presence of hypokalaemia only.