Study of pattern & distribution of adverse drug reactions in acute coronary syndrome patients in a tertiary care hospital.

Background & objectives: With the availability of a wide range of drugs to treat patients with acute coronary syndrome (ACS), adverse drug reactions (ADRs) have become inevitable in clinical practice. Thorough knowledge of such reactions is essential for the treating physician for optimal treatment and better outcomes. There are many scales to define, measure and assess the ADRs, but there is a dearth of data available on such drug reactions among ACS patients. Hence, this study attempted to analyze the pattern, causality, severity, predictability and preventability of ADRs in ACS patients. All the ADRs reported during the study period were analyzed for causality by the World Health Organization-Uppsala Monitoring Centre (WHO-UMC), Naranjo's and Karch and Lasagna scales; severity by modified Hartwig and Siegel scale; predictability by Rawlins and Thompson criterion and preventability by Schumock and Thornton scale. Methods: A single-centre, record-based analysis for the occurrence of ADRs was done among ACS patients admitted to the department of Cardiology between January and October 2017. Demographic data, comorbid conditions, reported ADRs and ADR assessment details were noted from the hospital case records and ADR monitoring centre (AMC) records. The data were analyzed and presented in a descriptive manner using percentages, mean and standard deviation. The Pearson's chi-squared test was used to ascertain the significance of the association between different groups. Results: Out of 324 patients under evaluation, 67 had developed one or more ADRs. There were 30 different types of ADRs reported, headache being the most common. Among the drugs, heparin was the most common factor, causing 27 per cent of ADRs. Definite causality of a suspected drug causing ADRs was seen in 11.9 (n=8), nine (n=6) and 7.5 (n=5) per cent cases as per WHO-UMC, Naranjo (Naranjo algorithm) and Karch and Lasagna scales, respectively. In the severity of ADRs, the most severe reactions according to the modified Hartwig-Siegel scale (level 4a in our study) were seen in 17.5 (n=12) per cent of patients, and the rest were either level 2 or 3 reactions. Nearly 92.5 (n=62) per cent of reactions were predictable according to the Rawlins and Thompson criterion. Application of the modified Schumock-Thornton scale showed that 22.4 per cent of ACS patients had preventable reactions, and the rest were not preventable. Interpretation & conclusions: The study results suggest that ADRs are relatively common among ACS patients. Most of these can be identified and assessed for causality, severity, predictability and preventability using various available scales. Diligent pharmacovigilance for identifying and assessing ADRs may help manage and mitigate morbidity associated with these in high-risk ACS patients.