The First 24 Hours of Hospital Admission: Early Opportunity for Pharmacotherapy Optimization in Elderly Patients with Chronic Kidney Disease

Chronic kidney disease (CKD) affects more than 10% of the global population and represents one of the leading causes of mortality. This study aimed to assess the pharmacotherapy of hospitalized patients aged ≥ 65 years with CKD, focusing on the prevalence of polypharmacy, potentially inappropriate medications (PIMs), potentially clinically significant drug–drug interactions (DDIs), the use of renal-risk drugs (RRDs). A prospective observational study was conducted at the Department of Nephrology and Dialysis of University Hospital Dubrava, including 100 participants. A clinical pharmacist obtained the Best Possible Medication History (BPMH) within 24 h of hospital admission. A total of 1324 comorbidities were recorded (median 12 per patient), along with 985 prescribed medications. Polypharmacy (5–9 drugs) was observed in 43% of patients, while excessive polypharmacy (≥10 drugs) was present in 48%. A total of 258 PIMs were identified, with 89% of patients having at least one PIM (mean 2.6 per patient). Nearly 94% of patients had significantly impaired renal function (G3–G5), and 82% were exposed to inappropriately prescribed RRDs. Contraindicated medications based on renal function were identified in 62% of patients, while 52% had at least one medication prescribed at an unadjusted dose. A total of 1097 potentially clinically significant DDIs were identified, with a mean of 10.9 interactions per patient. The results indicate a high prevalence of polypharmacy, PIMs, potentially clinically significant DDIs and inappropriately prescribed RRDs among older hospitalized patients with CKD, increasing the risk of adverse events and unfavorable treatment outcomes. The findings highlight the importance of the 24 h period following hospital admission as an early opportunity for identifying medication-related problems and optimizing pharmacotherapy in highly vulnerable patients, such as elderly patients with CKD. The study also emphasizes the importance of early involvement of a clinical pharmacist in the pharmacotherapy review and obtaining the BPMH.