Objective: Drug-related problems (DRPs) can lead to treatment failures and high risks of hospitalization. This study aimed to evaluate the effect of pharmacist-led interventions on DRPs in outpatient prescribing and to determine the risk factors relative to these DRPs.

Material and Methods: A prospective study was conducted that compared before- (April 1 to June 30, 2020) and after- (June 1 to June 15, 2021) interventions on the outpatient prescribing process from a public hospital in Vietnam. The PCNE classification version 9.1 and suitable drug information were used to determine DRPs, which then used Drugs.com to find drug-drug interactions for each prescription. Collaborated with hospital pharmacists via reporting on the pre-intervention results, sending information sheets, and reminding doctors of the DRPs was conducted.

Results: 32.8% of prescriptions had at least 1 DRP in 500 pre-intervention prescriptions. In 500 post-intervention prescriptions, the proportion of at least 1 DRP prescription decreased from 32.8% to 31.0% (p-value>0.05). Prescriptions with ≥5 drugs increased the possibility of a DRP appearance (p-value
Conclusion: This intervention method was not thorough, so it was ineffective in reducing DRPs on outpatient prescriptions. It is necessary to conduct specific interventions on each DRP and more time to discuss with doctors to improve the effectiveness of prescribing.

Keywords: drug-related problem, outpatients, pharmacist, prescriptions, Vietnam