Drug Dosing Regimens

May 29, 2007 — A review published in the May 15 issue of American Family Physician provides various drug dosing regimens and principles for appropriately treating patients with chronic kidney disease.

"Chronic kidney disease affects renal drug elimination and other pharmacokinetic processes involved in drug disposition (e.g., absorption, drug distribution, nonrenal clearance [metabolism])," write Myrna Y. Munar, PharmD, BCPS, and Harleen Singh, PharmD, from the Oregon State University College of Pharmacy in Portland. "Physicians should be familiar with commonly used medications that require dosage adjustments. Resources are available to assist in dosing decisions for patients with chronic kidney disease."

The review notes that drug dosing errors are common in patients with renal impairment, sometimes causing adverse effects and poor outcomes. To avoid these errors, dosages of drugs cleared renally should be adjusted based on creatinine clearance or glomerular filtration rate (GFR) and should be calculated with online or electronic calculators.

For maintenance dosing adjustments, recommended methods are dose reductions, less frequent dosing interval, or both. Loading doses usually do not need to be adjusted in patients with chronic kidney disease.

The National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (K/DOQI) defines chronic kidney disease as the prese