Investigation on potential risk factors for adverse events associated with polypharmacy in elderly patients with chronic kidney disease

Abstract

Polypharmacy in elderly patients represents a potential increase in the use of inappropriate drugs that may lead to an increased risk of adverse events. In this study, we aimed to clarify the relationship between the stages of chronic kidney disease (CKD) and use of inappropriate drugs that can result in polypharmacy in elderly CKD patients. Patients aged 65 years or older, who were hospitalized between January 2016 and June 2016 (n = 647), were classified according to their CKD stages determined by the categories of glomerular filtration rate (GFR). The regular medications that patients were taking at the time of hospital admission were examined in terms of dosage regimen, and polypharmacy was defined as the use of six or more of these drugs. In addition, we examined the potential risk factors for adverse events associated with polypharmacy in elderly patients or patients with decreased kidney function, and whether the drugs were discontinued or changed during hospitalization. The results showed that the rate of polypharmacy was 42.0% in patients with stage G1/2, while it was 84.1 and 90.5% in those with stage G4 and G5D, respectively. The usage of different dosage regimens significantly increased in patients with stage G4 or more severe CKD compared to patients with stage G1/2. The proportion of prescribed drugs that were considered potential risk factors for adverse events in elderly patients was significantly higher in patients with stage G4 (84.1%) and G5D (71.4%) than in patients with stage G1/2 (50.7%). Meanwhile, the proportion of prescribed drugs that were considered potential risk factors for adverse events in patients with decreased kidney function was 33–50% in each GFR category. However, this proportion was relatively small and no significant differences were observed. The characteristics of different drugs were identified according to the GFR categories. The proportion of drugs that were discontinued or changed during hospitalization was higher in patients with stages G4 and G5 than in other GFR categories. This study demonstrated that with the progression of CKD, elderly patients tended to show an increased rate of polypharmacy as well as intake of drugs, which can be potential risk factors for adverse events. In addition, the results of study suggest that the pharmacological management of prescription drugs, which are considered potential risk factors for adverse events, according to the CKD stage of the patient is important.