Frequency and Predictors of Inappropriate Medication Dosages for Cardiovascular Disease Prevention in Chronic Kidney Disease Patients: A Retrospective Cross-sectional Study in a Malaysian Primary Care Clinic

Patients with chronic kidney disease (CKD) are at increased risk of cardiovascular events. This study aimed to assess the frequency of inappropriate medication dosages (IMD) for cardiovascular disease prevention among patients with CKD and its predictors in an urban academic primary care clinic in Selangor, Malaysia. All patients who attended the clinic from April to June 2019 and fulfilled the inclusion criteria were included in this cross-sectional study, except for those with an estimated glomerular filtration rate (eGFR) of more than 90 ml/min, diagnosed with urinary tract infection, pregnant or were on dialysis for end stage renal disease. Their prescriptions on the electronic medical record (EMR) system were evaluated for appropriateness using the dose adjustment recommendations based on the 2018 Malaysian Clinical Practice Guidelines on management of CKD. A total of 362 medical records were included in this study. 16.6% (95% Confidence Interval [CI]: 12.9-20.8) or 60 out of 362 of the patient records analysed contained medications prescribed with inappropriate dosages. Patients with higher stages of CKD were associated with higher odds of IMD, namely CKD stage G3b (adjusted Odds Ratio [aOR] 10.41; 95% CI: 2.31-46.88) and CKD stage 4-5 (aOR 15.76; 95% CI: 3.22-77.28). Other predictors of IMD were diagnosis of diabetes mellitus (aOR 6.40; 95% CI: 2.15-19.01), number of prescribed medications of 5 or more (aOR 4.69; 95% CI: 1.55-14.20), and eGFR reduction of more than 25% over one year (aOR 2.82; 95% CI: 1.41-5.65). Within the limitations of this study, we conclude that the occurrence of IMD for CVD prevention was low in CKD patients in this primary care clinic. Medications with inappropriate dosages identified in this study include simvastatin, fenofibrate, hydrochlorothiazide, spironolactone, metformin, gliclazide, sitagliptin, dapagliflozin and empagliflozin. Clinicians should consider the predictors of inappropriate medication dosages listed above when prescribing to patients with CKD to reduce the risk of medications-related toxicities and adverse effects. Limitations of this study should be considered when interpreting the findings presented.