Diuretics as initial treatment for essential hypertension.

1 In the United States, the thiazide diuretics are considered the cornerstone of all antihypertensive regimens for four reasons: by themselves, they are capable of controlling the blood pressure in 60-70% of the hypertensive population; they prevent the sodium retention produced by all other antihypertensive agents; they can be given once a day; and they are inexpensive. 2 Despite these advantages, the thiazide do cause hypokalaemia hyperuricaemia and hyperglycaemia. The incidence of hypokalaemia (K less than 3.0 mEq/l) is only 2-4%; the incidence of hyperuricaemia (uric acid greater than 10 mg per cent is 3-4%; and the incidence of hyperglycaemia is 1-2%. 3 The possibility that a beta-blocking agent combined with a thiazide diuretic might produce better BP control, prevent thiazide-induced abnormalities and exert a coronary prevention action with once daily administration would suggest that such a combination should be the ideal initial therapy for most patients with hypertension.