A prospective pharmacovigilance study in the infectious diseases unit of a tertiary care hospital

Introduction: The frequency, causality, severity, preventability and risk factors of ADRs (adverse drug reactions) in infectious disease units are not well defined in the literature. Thus, the aim of this study was to determine the characteristics of the ADRs encountered in an infectious disease unit of a tertiary teaching hospital. Methodology: The patients who were admitted to the infectious disease unit of a tertiary teaching hospital longer than 24 hours between January and December of 2016 were followed prospectively. Patients were observed and questioned for any sign of ADRs. The proportion of ADRs and patient characteristics were investigated. Causality was evaluated by the Naranjo algorithm, severity was determined using the Hartwig classification, and preventability was assessed using the Schumock and Thornton scale. Results: 210 patients were admitted to the unit during the study period, of whom 44 patients (20.9%) experienced 51 ADRs. 5.9% of ADRs were found to be serious according to the Hartwig severity classification. In addition, 88.1% of ADRs were not preventable. The most frequently detected ADR was skin and subcutaneous tissue reactions (33.3%), and systemic antimicrobials were the most common type of drugs that caused an ADR. Prolonged hospitalization (p < 0.001) and usage of an increased number of drugs (p < 0.001) were found to be significant risk factors for ADR development. Conclusions: Prolonged hospital stay and polypharmacy are significant risk factors that increase the incidence of ADRs in infectious disease units. The likelihood of unavoidable ADRs should arouse the attention of clinicians when prescribing antimicrobials.