Epidemiology of medication-related problems and antimicrobial utilisation among critically ill cancer patients: Determinants, pharmacist interventions and clinical outcomes—A prospective observational study

BackgroundCritically ill patients with cancer are highly vulnerable to medication-related problems (MRPs) because of complex treatment regimens, organ dysfunction, immunosuppression, and extensive antimicrobial exposure.ObjectivesTo determine the prevalence, patterns, and determinants of MRPs; describe antimicrobial utilisation; evaluate clinical pharmacist interventions; and assess clinical outcomes.MethodsA prospective observational study was conducted over 14 months in an oncology ICU of a tertiary cancer centre. Adults admitted for ≥48 h were enrolled. MRPs were identified using the Pharmaceutical Care Network Europe classification V9.1. Antimicrobial utilisation was measured as defined daily doses (DDD) per 100 bed-days and classified according to WHO AWaRe categories. Pharmacist interventions were documented. Multivariate logistic regression identified predictors of MRP occurrence.ResultsAmong 325 patients (mean age 54.6 ± 12.3 years; 58.5% male), 268 (82.5%) experienced at least one MRP, with 612 identified (mean 1.88/patient). Treatment-effectiveness (38.1%) and treatment-safety (28.9%) problems predominated. Antimicrobials were prescribed in 296 patients (91.1%), with consumption of 142.6 DDD/100 bed-days; Watch agents accounted for 54.2%. Pharmacists made 540 interventions, of which 466 (86.3%) were accepted. Polypharmacy, prolonged ICU stay, renal impairment, hematological malignancy, and use of ≥2 concurrent antimicrobials independently predicted MRP occurrence. Mortality was higher among patients with unresolved or severe MRPs than among those without MRPs (34.2% vs 18.6%, p = 0.002).ConclusionMRPs were highly prevalent and associated with medication burden, organ dysfunction, malignancy type, and antimicrobial exposure, while pharmacist interventions showed a high acceptance rate, supporting their potential role in medication safety and antimicrobial stewardship.