Drug–drug interactions (DDIs) are one of the most common problems related to drug administration which represent a risk for patient safety. Considering their position in the healthcare system, pharmacists should be more proactively involved in DDI management. The paper shows representation of DDI intervention models in each DDI category. This research enrolled outpatients prescribed pharmacotherapies from 40 randomly selected community pharmacies. DDIs were analyzed using Lexicomp^® Lexi-InteractTM Online (Lexi-Comp, Inc., Hudson, NY, USA) software. Clinical pharmacists’ panel, according to the necessary interventions, determined an independent model of pharmacist interventions (category 1) and models that require cooperation with physicians (category 2) for DDI management. In total, 4107 patients were enrolled in the study. Mean patient age was 67.5; they were mostly women (56.5%) and had on average of 3.4 diagnosis and 5.5 prescription drugs. Overall, 14,175 potential clinically significant DDIs were identified: 83.3% of C, 15.4% of D, and 1.3% of X category. At least one potential DDI was found in 78.6% of patients. Models of pharmacist DDI interventions in collaboration with a physician (category 2) were more prevalent than independent models (category 1): 57.5% vs. 42.5% in C category DDIs, 97.8% vs. 2.2% in D category, and 100% vs. 0% in category X DDIs. This research aimed to gain an insight into the distribution of interventions in DDI management models between physicians and pharmacists, which can contribute to more efficient pharmaceutical care and visibility.

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.