Abstract
Background: Adverse drug reactions (ADRs) have become a major clinical problem causing additional burden on the total cost of a patient’s treatment.

Aims and Objectives: To determine the characteristics of ADRs reported in a tertiary care center.

Materials and Methods: Descriptive analysis of ADRs reported to the Department of Pharmacology over a period of 2 years from July 2012 to June 2014 was done. ADR reports were analyzed on the basis of patient characteristics, drug characteristics, predictability, preventability, severity, causality, and seriousness of the ADR. The continuous variables were expressed as mean ± standard deviation. Categorical variables were expressed as frequencies and percentages. Odds ratio (OR) was calculated to assess the risk factors for severe ADRs using SPSS 16.

Results: From the 359 ADR reports, 377 ADRs were identified with mean age 43 ± 19 years. 95.3% affected single organ system, the most common being skin and appendages. The most common ADR reported was maculopapular rash. Antibiotics accounted for the maximum ADRs of which beta-lactams were the most common. 30.1% (108) ADRs occurred within 1 h of administration of the drug. In 12.73% (48) drug interactions (DIs) were cause of ADRs. Risk analysis showed that DIs (OR = 2.25, 95% confidence interval [CI] = 1.1-1.53), concomitant use of more than one drug (OR = 1.75, 95% CI = 1.97-3.18) and delayed onset ADRs (OR = 1.89, 95% CI = 1.22-3.51) were risk factors for development of severe ADRs.

Conclusions: Skin and integumentary system was the most commonly affected system and beta-lactams were the most common drug class implicated to cause ADR.

Key words: Adverse Drug Reaction; Drug Interaction; Severity; Causality Assessment; Preventability