Complications, such as hypokalaemia and hyperglycaemia, occur mainly with doses higher than those needed to treat hypertension effectively, and are anyway reversible. Bendrofluazide, in a dose of 2.5 mg daily. Other drugs are less satisfactory and more expensive. Beta-blockers may be less effective than diuretics in preventing stroke. Calcium antagonists can cause postural hypotension, gastrointestinal upset, and ankle swelling in elderly patients.
ACE inhibitors are potentially dangerous in patients with renal or carotid artery stenosis.