Polypharmacy and Renal Failure in Nursing Home Residents: Results of the Inappropriate Medication in Patients with Renal Insufficiency in Nursing Homes (IMREN) Study

Abstract

Background: Polypharmacy has become an emerging public health issue in recent years, since use of multiple medications or polypharmacy is beneficial for many conditions, but may also have negative effects like adverse drug reactions. The risk further increases in patients with chronic renal failure, a comorbidity very frequent in nursing home residents. Since more than 50% of all drugs were renally excreted, dose adjustments in patients with renal failure are required.

Objective: To assess polypharmacy in German nursing homes, in particular in residents with renal failure.

Methods: Multi-center cross-sectional study in 21 nursing homes in Bremen and Lower Saxony/Germany. Baseline data were analysed using descriptive statistics. Multivariable logistic regression model and 95% confidence intervals were used to study the association of renal failure and polypharmacy.

Results: Of all 852 residents, the analysis comprised those 685 with at least one serum creatinine value so that the estimated creatinine clearance could be calculated. Of those, 436 (63.6%) had a severe or moderate renal failure, defined as estimated creatinine clearance <60 mL/min. Polypharmacy (5-9 drugs) was found in 365 (53.3%) and excessive polypharmacy (≥10 drugs) in 112 (16.4%) residents. Diuretics and psycholeptics were the most commonly used drug classes. Severe renal failure (estimated creatinine clearance <30 mL/min) was associated with polypharmacy (OR: 2.8, 95% CI 1.4-5.7).

Conclusion: Both, polypharmacy and renal failure are common in German nursing home residents and an association of both could be found. Further studies are needed to assess the appropriateness of polypharmacy in these patients.