Incidence, Associated Factors and Pharmacoeconomic Impact of Adverse Drug Reactions at a South Indian Tertiary Care Hospital: Need for a Continuous Monitoring System

The aim of the study was to analyze the incidence of adverse drug reactions (ADRs) at a tertiary care hospital and assess the functioning of the reporting system. The outcome of the study would provide information regarding associated factors and pharmacoeconomic impact of the ADRs. The causality assessment was determined by WHO UMC probability scale and Naranjo’s algorithm. Outcomes of ADR, management and the pharmacoeconomic impact was assessed. Overall incidence of ADRs among the patients was 4.5%. A total of 61 ADRs were detected from 54 patients. As per the WHO UMC scale 44.3% of the ADRs were possible and as per the Naranjo’s scale 53.1% of the ADRs were possible. Majority of the reactions were moderate in severity (47.6%). Most of the ADRs (73.8%) were predictable reactions and 39.3% were probably preventable. Multiple drug therapy (27.77%) was the most common associated factor. Withdrawal of the offending drug was the main line of management.  Symptomatic treatment was required in majority of cases. The total direct cost involved in treatment of ADRs was INR 1, 10,284 (US$ 1730.22) at a rate of INR 2042.29 US$ 32.08 per patient. The direct cost per patient involved in ADR related hospital admissions (INR 2689 i.e US$ 42.30) was higher than ADR during hospitalization (INR 1769.60 i.e US $ 27.83).The ADRs were not recognized and recorded in majority of the cases. Patients on multiple drug therapy are more vulnerable to ADRs. The incidence and alarming pharmacoeconomic impact of the ADRs suggest that there is a need for a continuous monitoring system at tertiary care hospitals.