Abstract

Mild to moderate hypertension usually responds to a β-blocker or a thiazide diuretic. In many patients a combination of the two produces a greater fall in blood pressure than either drug alone, and is often effective in patients who fail to respond to a single drug.¹ The combination also has other advantages. β-Blockers prevent the increase in plasma renin activity which sometimes reduces the hypotensive response to a diuretic.^{2 3} β-Blockers at least acutely cause a small rise in plasma potassium which may tend to counteract the mild hypokalaemia produced by thiazides.^{4 5} If fluid retention is caused by the β-blocker,⁶ the diuretic can reverse it.