The excellent article on safe drug prescribing for patients with renal insufficiency addresses many questions that pharmacists are asked by physicians in daily practice.1
However, in Table 5 a statement on COX-2 selective NSAIDs would have been useful, as many physicians believe that these agents have less potential to adversely affect renal function than older nonselective agents. No evidence exists to support this belief. The new COX-2 selective agents are similar in net effects on renal prostaglandin function to the older nonselective NSAIDs.2,3
In addition, another nephrotoxic drug class to watch out for is radiocontrast “dyes.” Exposure to intravenous radiocontrast agents for diagnostic and interventional procedures is quite common. Aside from considering non-ionic, low-osmolality agents and hydration, reasonable evidence suggests that pre-treatment with oral N-acetylcysteine may further reduce the risk of renal damage.4 Given its low cost and minimal toxicity, N-acetylcysteine should be considered in patients with renal insufficiency before they are exposed to parenteral radiocontrast agents.
Bruce Lange Clinical Pharmacist, Nephrology Royal Columbian Hospital New Westminster, BC
References
- 1.Kappel J, Caliss, P. Nephrology: 3. Safe drug prescribing for patients with renal insufficiency. CMAJ 2002;166(4):473-7. [PMC free article] [PubMed]
- 2.Brater DC. Effects of NSAIDs on renal function: focus on COX-2 selective inhibition. Am J Med 1999;107(6A):65S-71S. [DOI] [PubMed]
- 3.Kaplan-Machlis B, Klostermeyer B. The cyclooxygenase-2 inhibitors: safety and effectiveness. Ann Pharmacother 1999;33:979-88. [DOI] [PubMed]
- 4.Tepel M, van der Giet M, Schwartzfeld C, Laufer U, Liermann D, Zidek W. Prevention of radiographic-contrast-agent-induced reductions in renal function by acetylcysteine. N Engl J Med 2000;343:180-4. [DOI] [PubMed]