A prospective study on prevalence of adverse drug reactions due to antibiotics usage in otolaryngology department of a tertiary care hospital in North India.

Background: Polypharmacy, advancing age and longer duration of hospital stay are the factors responsible for adverse drug reactions (ADRs). This study has attempted to analyze the pattern of antimicrobial prescription in OPD & IPD of the Otolaryngology department and to detect, document, assess and report the suspected ADRs due to antibiotic use and preparation of guidelines to minimize the incidence of ADRs. Methods: A prospective study conducted at the TMMC&RC on patients aged >40 years, who visited the Otolaryngology department over a period of 5 months. Suspected ADRs were assessed for causality and severity using Naranjo’s probability scale and modified Hartwig’s criteria, respectively. Results: Out of 1200, 925 prescriptions were analyzed. Most patients were from 41-60 age (59.45%) followed by 61-80 age (37.29%) and least from >80 yr (3.24%). But the incidence of ADRs were found to be higher in patients of >80 yr age group n=8 (26.66%). The most commonly prescribed antibacterials were β-Lactams (64.61%). Out of 925 prescriptions studied, only 94 were found to have 154 ADRs. The most commonly identified ADRs were Gastrointestinal 47.40%, followed by Neurotoxicity 24.67%, cutaneous reactions 20.12%, Hepatic 4.54% and Kidney 3.24%. 74.67% of the ADRs were probable and 20.77% were possible type and only 4.54% were definite. 74.67% ADRs were found to be type A, and 25.32% type B. Conclusions: Our study showed that prevalence of ADRs was highest in elder age group and diarrhea was the most common ADR found. Therefore elderly patients should be given special attention when prescribing medications to avoid clinically significant harmful consequences. Minimizing unnecessary antibiotic use by even a small percentage could significantly reduce the immediate and direct risks of drug-related adverse events in individual patients.