Monitoring, reporting and causality assessment of adverse drug reactions among admitted adult patients at a tertiary care teaching hospital: a prospective observational study

Background: Adverse drug reactions (ADRs) add avoidably to illness, lengthen hospital stays and cost lives, yet they go under-reported in many wards. We set out to capture and report ADRs in admitted adult patients and to characterise their pattern, causality, severity, preventability and management at a tertiary care teaching hospital. Methods: Over six months (21 March 2023 to 21 September 2023) we ran a prospective, cross-sectional, observational study based on spontaneous reporting among patients older than 18 years admitted to General Medicine, Surgery, Dermatology and Psychiatry. Suspected reactions were weighed for causality with the World Health Organization-Uppsala Monitoring Centre and Naranjo scales, for severity with the Hartwig and Siegel scale, and for preventability with the Schumock and Thornton criteria. Data were summarised with descriptive statistics and the chi-square test. Results: Fifty-four ADRs arose in 38 patients across 5192 admissions, an incidence of 1.04 per 100 admissions. Reactions clustered in the 46–60-year age group and were more common in males (35.08%). Predictable type A reactions dominated (88.89%). The endocrine system was affected most often (22.22%), and hypoglycaemia was the single commonest event. Antidiabetics (19.29%) and antibiotics (12.28%) were the drug classes implicated most frequently. On Naranjo assessment the majority were probable (83.33%), and 94.44% were of moderate severity. Stopping the suspected drug (70.37%) was the mainstay of management, and 83.33% of patients improved. Conclusions: The reactions seen here were largely predictable, moderate and preventable, driven chiefly by polypharmacy and coexisting illness. Disciplined spontaneous reporting and prescriber education are key to safer medicine use.