Hypertension, renal disease, and drug considerations

Abstract

The incidence of chronic kidney disease is steadily increasing in the United States. The magnitude of this problem is such that virtually all health care providers are being called upon to manage these patients. The interplay between chronic kidney disease and drug therapy is complex in that the kidney is both a target for drug effect as well as a moderator of drug elimination. Renal drug elimination occurs by filtration, secretion, and/or metabolism. For renally-cleared compounds, drug clearance typically falls in tandem with the loss of renal function. This process is noteworthy for drug accumulation when the glomerular filtration rate approaches the 30-cc/min range. The kidney is a target for drug effect in relationship to blood pressure and protein excretion. Angiotensin-converting enzyme inhibitor and angiotensin receptor blocker therapy (usually given along with a diuretic) are the drug classes that have been shown to be effective for reduction in both blood pressure and protein excretion in the chronic kidney disease patient. A number of questions still remain unanswered in the pharmacotherapy of chronic kidney disease, including the optimal dose for these drugs as well as what represents the most favorable achieved blood pressure.

Figure 1

Stages of chronic kidney disease: National Kidney Foundation Kidney Diseae Outcomes Quality Initiative Classification. GFR=glomerular filtration rate; CKD=chronic kidney disease; ESRD=end stage renal disease; RCN=radiocontrast nephropathy. Adapted from the National Kidney Foundation. Am J Kidney Dis. 2002;39 (suppl 2):S1‐S246.