Characteristics of drug-related problems and the impact of pharmacist interventions on hospital drug costs in the medical intensive care unit

Background: Pharmaceutical care activities have been reported to enhance treatment outcomes and cost-effectiveness in critically ill patients. However, relevant and timely data on this topic are still lacking in Thailand. Objectives: The objective of the study is to investigate the characteristics of drug-related problems (DRPs) identified during pharmaceutical care activities at the medical intensive care unit (MICU) of a tertiary care teaching hospital in Thailand. In addition, we aimed to quantify the impact of pharmacist interventions on hospital drug costs. Materials and Methods: DRPs identified during pharmaceutical care activities over 3 years were reviewed and classified by the Pharmaceutical Care Network Europe. The severity of these DRPs was categorized by the National Coordinating Council for Medication Error Reporting and Prevention. The impact on hospital drug costs was calculated on the day of the pharmacist’s intervention as the variance in actual drug costs per day between the previous therapy and the new therapy. Results: Out of the 1,407 patients admitted to the MICU, 140 patients (10.0%) developed 180 DRPs. Within the problem domain, 51.1% of DRPs were related to treatment effectiveness. Prescribing and drug selection were the leading causes of DRPs, accounting for 95.0%. Anti-infective agents were the most common drug group associated with DRPs. The majority of DRPs were classified as non-harmful, with the primary issue being a drug dose that was too low, leading pharmacists to recommend dose increases. As a result, hospital drug costs elevated by 22,984 Thai Baht, equivalent to 628 United States dollars. Conclusion: Majority of the DRPs in the MICU were associated with treatment effectiveness, primarily due to issues in prescribing and drug dose selection. Dose escalation interventions led to an overall increase in hospital drug costs. To highlight the economic value, it is important to measure the cost of treatment associated with DRPs that could be prevented through pharmacist intervention.