Evaluation of Adverse Drug Reactions Due to Fixed-dose Combinations at a Tertiary Care Hospital: An Observational Retrospective Study

Abstract

Introduction: The mushrooming of Fixed-dose Combinations (FDCs) has been observed in the past decade in the Indian market. The majority of these FDCs are irrational and put patient safety at risk. Aim: To evaluate Adverse Drug Reactions (ADRs) due to rational as well as irrational FDCs available in India. Materials and Methods: This was an observational, retrospective study where recorded data of ADRs reported over a period of 10 years (January 2011-December 2021) at the Regional Training Centre and ADR Monitoring Centre (B.J. Medical College and Civil Hospital, Ahmedabad, Gujarat, India) was analysed. The data evaluation was carried out from May 1, 2022, to December 15, 2022. Any ADR where FDC(s) was the suspected causal drug was included in the analysis. Out of a total of 8,218 reported ADRs in the ten-year duration, 1,575 ADRs were reported to have occurred due to FDCs. The data were analysed for age, gender, System Organ Class (SOC), suspected drug, seriousness of the ADRs, causality assessment, and outcome of ADRs, and presented in terms of numbers or percentages. Results: A total of 1,575 ADRs occurred due to 1,649 FDC(s). The most common SOC class of ADRs was Gastrointestinal (GI) disorders in 359 (23%) cases, followed by skin and subcutaneous disorders in 317 (20%). The common suspected groups were Anti-Retroviral (ARV) drugs in 787 (50%) ADRs, followed by antitubercular drugs in 298 (19%). Out of a total of 1,649 FDCs as the suspected drug, 1,551 (94%) were rational, and 98 (6%) were irrational. A total of 169 (11%) serious ADRs were reported, of which seven ADRs were due to irrational FDCs (prescribed for cold and cough). Causality assessment using the World Health Organisation-Upsala Monitoring Centre (WHO UMC) classification showed a possible causal association with the suspect FDCs for 1,385 (84%) ADRs. Conclusion: FDCs contribute to a significant proportion of ADRs, which could be prevented by avoiding the use of irrational FDCs and monitoring the patients for the possible development of ADRs.