To Identify Suspected ADRs and Establish Their Causal Relationship with Suspected Drug: An Institutional Based Study

Abstract

Background: ADRs as any response to a drug that is noxious, unintended and that occurs at a dose used in humans for prophylaxis, diagnosis or therapy, excluding failure to accomplish the intended purpose. The present study was conducted to identify suspected ADRs and establish their causal relationship with suspected drug. Materials and Methods: This prospective and observational study was conducted at hospitals in tertiary care teaching hospitals in western U.P. during a period from February 2018 to March 2019. All the necessary and relevant data was collected from patients like case notes, treatment charts, laboratory reports, ADRs notification forms as per CDSCO, patients interview and reporter’s interview. The noted ADRs were assessed by using Naranjo’s causalty of ADR assessment scale. All reported ADRs were evaluated for the following parameters using appropriate scale: Causality (Naranjo’s scale), Severity (Hartwig et al scale). Statistical analyses were performed. Results: The results showed that females were more reported patients than males who were on antihypertensive medication and over 95% patients were urban. Of all 28% patients were with comorbidities with hypertension. As per the report ADRs were found more among the patient treated with monotherapy of antihypertensives and less among those with polytherapy or fixed drug combination. CCBs have been the most common drug causing some adverse effect leading to discontinuation of drugs. And the most common affected organ system was central nervous system. And drug combination with lesser ADRs is CCB with diuretics which makes them better at treatment with lesser ADRs. The causality assessment done as per Naranjo’s scale and WHO-UMC scale which concluded the majority that is more than half of patients were classified as probable under both scales and rest under possible and very few under unlikely. The severity assessment was done as per Hartwig scale and all the patients fell into category of Mild level 1 and 2 which very well parallels with finding of causality scale. Conclusion: In the above pharmacovigilance study it was found out that adverse drug reactions reported by the commonly used antihypertensives was least with the poly therapy as compared to monotherapy. Causality assessment was done using Naranjo’s probability scale and more than half of reported ADRs were classified as possible and on WHO-UMC more than half of them were probable. Hartwig severity assessment concluded all the ADRs were only, mild and more than 2/3rd were level 2 mild ADRs. AS found the polytherapy with antihypertensives was associated with minimum adverse effects and hence could be preferred over monotherapy considering all the other physical and medical status of patient under control.