Patterns of Antimicrobials Prescribed to Patients Admitted to a Tertiary Care Hospital: A Prescription Quality Audit

Introduction Rational use of antimicrobial agents is necessary to prevent the emergence of drug resistance. This study aims to assess the prescription pattern of antibiotics using the Anatomic Therapeutic Chemical Classification (ATCC)/Defined Daily Dose (DDD) metrics in real-world practice. Methods A retrospective audit of antibiotics prescribed to patients admitted to a tertiary hospital over 20 months. The demographics and clinical information of patients were collected. The ATCC/DDD system was used to classify antibiotics. The DDD per 100 bed-days was calculated and the quality of prescription, including generic and parenteral formulation use, was evaluated. Results Nine-hundred ninety-four prescriptions were analyzed. The average number of antibiotics prescribed was 2±1. Only 23% of the patients had confirmed cases of bacterial infection. Imidazole derivatives (J01X) were the most prescribed antibiotics (68.8 DDDs per 100 bed-days) followed by cephalosporins (45.0 DDDs), beta-lactams (35.3 DDDs), fluoroquinolones (30.9 DDDs), and macrolides/lincosamides (14.4 DDDs). Sulphonamides/trimethoprim (4.7 DDD), aminoglycosides (0.8 DDD), penicillin (0.3 DDD), and carbapenems (0.1 DDD) were the least prescribed. Metronidazole was the most prescribed drug (34.2%). Generic names and parenteral formulations were used in 55% and 72% of antibiotics prescribed. Conclusion The continued low generics prescribing calls for interventions to be put in place to improve prescribing quality. Parenteral formulation prescribing encountered was very high, though this may not be unexpected in in-patients, it is vital to curtail the use of parenteral formulations so as to minimize the risk of infection. Irrational antibiotics prescription remains a serious concern in Nigeria. Drug utilization research using the ATCC/DDD metric is helpful in monitoring trends of drug use over time. This will help improve antibiotics stewardship and promote the rational use of antibiotics.