Prescribing medication in patients with impaired renal function

Abstract

Introduction: Renal failure has been emerging as a major public health problem in Nepal in recent years. Chronic renal failure affects renal drug elimination and other pharmacokinetic processes. Drug dosing errors are common in patients with renal impairment and can cause adverse effects and poor outcomes. Medications with toxic metabolites should be avoided, and alternative medications should be used if potential nephrotoxicity exist. Dosages of drugs cleared renally were adjusted according to creatinine clearance and glomerular filtration rate.

Methods:A Descriptive, cross-sectional study was conducted in TUTH. Data were collected from all the renal failure patients admitted at TUTH from 2009 February to April 2009. Parameters studied included age group, gender, duration of hospital stay, causes of renal failure, any associated comorbidity, serum creatinine (Scr) at admission and at discharge, blood urea nitrogen (BUN) and different drugs prescribed. Creatinine clearance (Clcr) in ml/min/1.73 m2 was calculated by using Cockroft-Gault equation.

Results: Majority of patient (98.1%) had raised urea level. Renal function at the time of presentation showed that 39.5 % patients had End stage renal failure and 39.5%, 19.7% and 1.3% patients had severe impairment, moderate impairment and mild impairment respectively. Average number of drugs prescribed was 5 to 6. In the list of prescribed medicine, 23% were antibiotic. Of the total antibiotic prescribed, dose adjustment was done for 27.3% and 1.5% drugs were prescribed which are supposed to be avoided in renal failure patients. Similarly in non-antibiotic group, 62.9% drug don’t required dose adjustment (they are safer in renal failure), dose adjustment was done in 22.9 %. The mortality rate of the renal failure at TUTH was found to be 15.3%. Kidney diseases, diabetes and hypertension were found to be the common causes of renal failure accounting for 29.5 %, 24.8% and 22.9% respectively.

Conclusions: Most of the patients with renal failure had end stage renal disease at presentation. Though they were prescribed multiple drugs, only few had dose adjustment done and some were even prescribed nephrotoxic drugs.