Evaluating antimicrobial prescribing in a Tertiary Healthcare Institution in Nigeria

Background Regular evaluation of antimicrobials prescriptions is important for optimal use. Objective This study determined the prescription patterns, class and costs of antimicrobials in the adult out-patient pharmacy of a Teaching Hospital in Nigeria. Methods A 1-year retrospective study from 1st January to 31st December 2018. The data, which included identification code, age, sex, antibiotics prescribed, number of antibiotics per prescription, number of medicines per prescription, dosage form, generic prescribing, drug on the essential drug list, and cost, were used in the analysis. The Chi-square test and Analysis of Variance were used to compare our data with the WHO–developed antimicrobial prescription Guidelines for Anatomical Therapeutic Chemical and Defined Daily Dose assignment of 2019. Results From 450 patient records, significantly more females (70%) were prescribed with antimicrobials ( P = 0.0038). The prescription pattern showed that antimicrobials selection by class was significantly different ( P < 0.0001) (top three being Amino-penicillin > Nitroimidazoles > Fluoroquinolone). In addition, age differed significantly ( P < 0.0001) with 46–50 as the highest class. Dosage forms profile showed that the percentage of encounter with injections prescribed (1.8%) was less than WHO recommendation (13.4–24.1%). Most of the prescriptions (84.22%) were from the Essential Drug List. The average cost of prescriptions with two antimicrobials was the highest ($14.0807), then three ($10.7949), and one ($6.39858). The average number of drugs per prescription that had one (4.28), two (4.46), and three (5.55) antimicrobials, respectively, were more than double the average (2) recommended by WHO. Conclusion The study showed that most of the patterns are within limit, however, highlights the need for frequent evaluation.