INTRODUCTION AND AIMS: Drug prescription is difficult to manage in patients with chronic kidney disease (CKD), since the decline in glomerular filtration rate (GFR) can markedly alter drug pharmacokinetics and pharmacodynamics. We assessed the prevalence and determinants of inappropriate drug prescriptions (whether contraindications or overdoses) with regard to kidney function in patients with CKD under nephrology care. We also assessed the impact of the equation used to estimate GFR on the prevalence estimates.
METHODS: The Chronic Kidney Disease-Renal Epidemiology and Information Network (CKD-REIN) cohort includes 3011 outpatients (median age 69, 66% men, 43% diabetic) with CKD (estimated GFR [eGFR] between 15-60 mL/min per 1.73m2) and at least one drug prescription. We examined the daily doses of pharmacological agents prescribed at study entry. Inappropriate prescription was defined as the reported prescription of either a contraindicated drug or an indicated drug at an excessively high dose level with regard to the patient’s eGFR, as estimated with the CKD-EPI equation, the de-indexed CKD-EPI equation, or the Cockcroft-Gault equation. Multivariate logistic regression was used to assess the determinants of inappropriate prescription risk, i.e. exposure to at least one inappropriate prescription.
RESULTS: At baseline, patients' mean eGFR was 33 mL/min per 1.73m2, with the CKD-EPI equation, 36 mL/min, with de-indexed CKD-EPI equation, and 41 mL/min with the Cockcroft-Gault (CG) equation. The median [IQR] number of drugs prescribed per patient was 8 [5-10]. When using the CKD-EPI equation to evaluate kidney function, 52% of the patients had been prescribed at least one inappropriate drug. Anti-gout, cardiovascular agents, and antidiabetic agents accounted for most of the inappropriate prescriptions, with respectively 41%, 27% and 21% of patients treated with these drugs having at least one inappropriate prescription. The percentage of inappropriate prescriptions varied from one GFR equation to another: 47% when using de-indexed CKD-EPI equation and 41% with the Cockcroft-Gault equation. Multiple logistic regression showed significantly higher odds-ratios for inappropriate prescriptions in men than women, in patients with than without diabetes, and in those with higher BMI, lower GFR and higher number of prescribed medications.
CONCLUSIONS: Our results emphasize the complexity of drug management for CKD patients, for whom inappropriate prescription appears to be common. Future research must assess the impact of inappropriate prescriptions on iatrogenic events, hospitalizations, and mortality.
Comments