Drug Utilization Review of Monitored Parenteral Antimicrobials in a Tertiary Care Private Hospital in Cebu City.

Abstract

Background: Based on the 2017-2020 annual report of the Department of Health-Antimicrobial Resistance Surveillance Program, significant resistance patterns have been observed for common disease-causing pathogens. In the hospital setting, antimicrobial stewardship programs have been implemented to optimize the use of antimicrobials. Drug utilization review studies provide essential feedback to improve prescribing and use of medications.

Objectives: This study aimed to review drug utilization of monitored parenteral antimicrobials among patients admitted from January to December 2019.

Methods: The study employed a retrospective, cross-sectional, descriptive research design. A retrospective chart review of drugs administered to patients was conducted.

Results: A total of 821 patients charts met the inclusion criteria. The patients' ages ranged from 18 to 98 years old and 52% were females. General Internal Medicine practitioners (28%) were the top prescribers of monitored parenteral antimicrobials primarily for the management of moderate-risk community-acquired pneumonia (39%). They were mostly indicated for empirical treatment of infections (94%) and were given for an average of 5.73 days.Only 58% of the total cases had orders for culture and sensitivity testing. Of which, principally 47% had colony cultures. Blood (29%) and sputum (27%) were the most common specimens taken for culture and sensitivity testing. The microorganisms often isolated were Escherichia coli (19%), Klebsiella pneumoniae (18%), and Staphylococcus aureus (9%). In addition, extended-spectrum beta lactamase-producing gram-negative pathogens (4%) and methicillin-resistant S. aureus (1%) were also isolated. All the microorganisms isolated showed most resistance to ampicillin (81%) and most susceptibility to colistin (100%). There were drug therapy-related problems encountered. There was one case of an adverse drug reaction (0.1%) and two cases of contraindications (0.2%). Therapeutic duplication was also observed in 5% of the cases. Moreover, 39% had instances of drug-drug interactions.Piperacillin-tazobactam had the highest consumption (79.50 defined daily doses/1,000-patient days) among the monitored parenteral antimicrobials.Some prescriptions were deemed inappropriate upon evaluation. 12% of cases were inappropriate based on the justification indicator. As for the critical indicators, duration of therapy (78%) was the main reason. Only four components of the DUE criteria indicators have met or exceeded the established threshold level.The cost analysis indicated that the total actual cost of therapy with the monitored parenteral antimicrobials amounted to ₱17,645,601.73. Considering Department of Health National Antibiotic Guidelines recommendations, ideal total cost of treatment was ₱14,917,214.29. Potential cumulative cost savings of ₱2,728,387.44 could have been achieved for patients admitted last 2019.

Conclusion: Consumption of piperacillin-tazobactam was relatively high as compared to the other monitored parenteral antimicrobials covered in this study. Physicians at the study site seldom prescribe monitored parenteral antimicrobials as recommended by the National Antibiotic Guidelines. This is evidenced in the incidence of inappropriate therapy regimens, with inapt duration of therapy as the leading explanation.From the patient's perspective, the main economic implication was on the direct medical costs, particularly the increased cost of the actual antimicrobial therapy prescribed to manage various infections. Adherence of physicians to the established guidelines and selection of the most cost-effective therapy could have resulted in considerable cost savings.