A retrospective cohort study of prescribing outcomes in outpatients treated with nirmatrelvir-Ritonavir for COVID-19 in an interdisciplinary community clinic.

Background: Large observational studies have demonstrated the real-world effectiveness of nirmatrelvir-ritonavir in preventing severe COVID-19 in higher risk individuals, but have provided limited information on other aspects of nirmatrelvir-ritonavir use. Our objective was to evaluate prescribing outcomes such as the prevalence of drug-drug interactions (DDI), adverse drug events (ADE) and treatment adherence in an outpatient community clinic setting.

Methods: We conducted a single-centre retrospective cohort study of adult outpatients prescribed nirmatrelvir-ritonavir in our community COVID-19 assessment clinic in Toronto, Ontario between March 3 and September 20, 2022.