Calcium antagonists and the kidney.

Calcium antagonists are frequently used to treat patients with hypertension or ischaemic heart disease. These patients often have renal impairment, so the effects of calcium antagonists on the kidney are important. The effects of calcium antagonists on renal haemodynamics are variable and depend on the state of the patient or animal and the dose of calcium antagonist used. Calcium antagonists cause natriuresis and diuresis by a mechanism which is not fully understood, but which is probably not directly due to the effects of calcium antagonists on renal haemodynamics. The diuretic effect may be useful in limiting the oedema which would otherwise be induced by vasodilator therapy. The effects of calcium antagonists on peripheral renin activity are unpredictable: renin release may be affected directly, as well as via haemodynamic effects. The pharmacokinetics of calcium antagonists are little changed in renal failure, since these drugs are metabolised in the liver. Calcium antagonists appear to be safe and useful treatments for patients with hypertension or ischaemic heart disease and co-existing renal impairment.