Evaluation of Clinical Pharmacist Interventions on Drug-Related Problems in an Outpatient Pharmacotherapy Clinic: A Prospective Structured Follow-Up Study

Background Drug-related problems (DRPs) are prevalent in outpatient settings and may result in adverse drug reactions and medication errors. Pharmacists are crucial in identifying and resolving DRPs, particularly for patients with chronic conditions and those on multiple medications. This study assessed the impact of pharmacist interventions on identification and resolution of DRPs, focusing on their prevalence, effectiveness, and acceptance by patients and physicians. Methods This prospective interventional study included adult patients with at least one chronic condition and two or more long-term medications. DRPs were identified through comprehensive medication reviews and categorized using the DOCUMENT classification system. Interventions were provided by clinical pharmacists, and outcomes were assessed at two structured follow-ups: a telephone follow-up at two weeks and an in-person visit at four weeks. Results A total of 411 DRPs were identified, with undertreated indications (32.6%), education/information gaps (13.9%), and monitoring issues (13.1%) being the most common ones. The prevalence of DRPs was higher in males than females (5.1 vs. 3.3, P = 0.002). Pharmacists implemented 411 interventions, with 75.1% directed at patients and 24.8% involving referrals to physicians. The overall acceptance rate was 68.3% for patient-related interventions and 50% for physician-related interventions. Conclusion Pharmacist-led interventions in outpatient care significantly contributed to the identification and partial resolution of DRPs. Structured follow-up visits and patient education improved medication safety and highlighted the value of integrating clinical pharmacists into routine outpatient care..