Incidence and Patterns of Adverse Drug Reactions Among Adult Patients Hospitalized in the University of Gondar Comprehensive Specialized Hospital: A Prospective Observational Follow-up Study

Background: Adverse drug reactions (ADRs) have continued to be a public health challenge with significant clinical and healthcare costs. However, little is known regarding the incidence of ADR in Ethiopia, particularly in the study setting. Thus, this study aimed to assess the incidence and patterns of ADRs in patients admitted to the University of Gondar comprehensive specialized hospital (UoGCSH).

Methods: A prospective observational follow-up study was conducted on admitted patients at the medical ward in the UoGCSH from May to August 2022. A multifaceted approach involving daily chart review and patient interviews was employed to collect the data. A standard Naranjo ADR Probability Scale measuring tool was used to characterize the probability of existing ADR. The data was analyzed using the Statistical Package for Social Sciences (SPSS) version 25. Logistic regression analysis was employed to determine the association between the occurrence of ADRs and other variables. A p-value at the 95% confidence interval was considered statistically significant.

Results: This study included 237 participants in total. The average length of follow-up was 16.4 (±5.2) days. Overall, 65 ADRs were identified, resulting an incidence rate of 27.4 (95% CI: 19.8-30.4) per 100 admissions. The most common ADRs were hypokalemia (10.7%), followed by constipation, diarrhea, hypotension, and rash (9.2% each). The majority of these ADRs (73.8%) were classified as "definite" by the Naranjo ADR probability scale. Gastrointestinal tract (GIT) (41.5%) and metabolic (18.6%) were the most frequently exposed systems for ADR. Antibiotics (26.2%) and cardiovascular medications (24.7%) were the most frequently implicated medications in existing ADRs. ADRs were significantly associated with age (p = 0.035), the presence of comorbidities (p = 0.021) and complications (p = 0.008), and receiving a higher number of medications (p = 0.04).

Conclusion: In this study, ADR was identified in about one-fourth of the participants. Older patients, patients with comorbidities and complications, and patients who received a higher number of medications were more likely exposed for ADRs. Healthcare providers should strictly follow the admitted patients to minimize ADRs.