Objective To assess antibiotic usage in gastrointestinal disorders with respect to appropriateness, pattern of resistance, and incidence of adverse drug reactions (ADRs).

Methodology Antibiotic prescribing in the gastroenterology department of a tertiary care hospital was evaluated using the Gyssens criteria and also by assessing drug related problems (DRPs) using the Pharmaceutical Care Network Europe V.6.2. A total of 173 patients were studied prospectively by a team of clinical pharmacists. Antibiotic susceptibility was prospectively studied; in addition, retrospective data on culture and sensitivity reports of commonly isolated organisms from 1 October 2012 to 30 September 2014 were collected to determine the resistance pattern in previous years. ADRs were evaluated using the Naranjo scale.

Results Antibiotic therapy was appropriate in 60% of patients and inappropriate in the remaining patients due to incorrect decision, choice, and use. A total of 184 DRPs and 30 ADRs of antibiotics were identified. In the study patients, the most commonly isolated organism was Escherichia coli (27.3%) followed by Klebsiella pneumoniae (16.7%). Both E coli and K pneumoniae exhibited 100% resistance towards cefotaxime. There was an increase in the resistance of E coli and K pneumoniae against various antibiotics tested in 2013–2014 as compared to the previous year. An empirical antibiotic policy was developed which was endorsed by the gastroenterology department.

Conclusions Although antibiotic therapy was appropriate in the majority of patients, irrational use occurred due to incorrect choice, improper dosage, and improper duration of therapy. E coli and K pneumoniae isolates showed an increase in resistance towards various antibiotics tested.