Update on calcium antagonists and the kidney

The treatment of hypertension has been proven to reduce cardiovascular and renal risk. The role of long-acting calcium channel antagonists in the management of hypertension has been confused in the past because of a lack of controlled clinical trials on people with hypertension and in subpopulations including those with diabetes and renal disease. The year 2002 saw the publication of the results of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial, the largest ever prospective drug-treatment trial, which involved 33 357 people with hypertension and included a calcium-antagonist group of 9048 individuals. Major publications on blood pressure control in people with kidney disease include the African American Study of Kidney Disease and Hypertension, and publications on people with diabetes include the results of the normotensive arm of the Appropriate Blood Pressure Control in Diabetes trial.

The main finding, from the studies reported in the last year, is that blood pressure control can be achieved using one or more of the first-line agents, including diuretics, calcium antagonists and angiotensin-converting enzyme inhibitors. On the basis of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial, diuretics make clinical and economic sense as initial therapy for those with hypertension. Calcium antagonists are well tolerated and effective and should be considered as the initial drug therapy when diuretics are not tolerated or when multiple drug therapy is indicated. Angiotensin-converting enzyme inhibitors should be used in people with nephropathy, and, in these patients, will nearly always need to be part of multiple drug therapy to achieve blood pressure control. When blood pressure control can be achieved in largely non-nephropathic populations, there is further evidence that the drug class used as initial therapy may not be important. One of the main themes coming from the literature in the last year is that renal function is increasingly being recognized as an important outcome measure and marker of cardiovascular risk.

The focus in blood pressure management must now be on identifying those with hypertension and bringing their blood pressure to target. For the majority of those with hypertension and renal disease, multiple drug therapy will be required, and, to achieve blood pressure targets, calcium antagonists are an appropriate part of this regimen. Particular attention is needed for nephropathic patients because of their higher risk of progression and the need for combination therapy; this group is likely to be the focus of future research and publications.