Dual blockade of the renin–angiotensin system in diabetic nephropathy

The presence of inadequately controlled hypertension in a diabetic patient with clinical signs of renal involvement portends a poor prognosis. Initial assessment should include ruling out factors which may exacerbate the hypertension and careful assessment of the stage of hypertension, renal function and amount of proteinuria. Intensive treatment requires finding a combination of medications which will reduce not only blood pressure but also proteinuria. It is suggested that treatment should be started with an ACE inhibitor or an AT1 receptor blocker often in a fixed combination with a low-dose thiazide diuretic. Calcium channel blockers and beta-blockers may be added if required as second or third-line agents. In patients not responding to this combination, the dosages of the ACE inhibitor or AT1 blocker should be titrated upwards in order to obtain the maximal therapeutic effect. However, if this is still insufficient, dual blockade of the RAS should be considered and even an aldosterone receptor blocker may need to be added to the therapeutic regimen. It should be remembered that such a patient requires close monitoring in order to be sure that he is compliant with respect to the prescribed treatment and that there are no side-effects such as hyperkalaemia.