RESUMEN
Key Clinical Message: The purpose of this case report is to reveal one of the cardiovascular side effects of favipiravir, sinus bradycardia. Abstract: Favipiravir has emerged as a potential treatment for COVID-19, with its antiviral properties showing promise in inhibiting viral replication. However, concerns regarding its safety profile, particularly its cardiac adverse effects, remain a subject of debate. We present the case of a 58-year-old man with a history of diabetes mellitus and chronic obstructive pulmonary disease who developed bradycardia following treatment with favipiravir for COVID-19 pneumonia. Despite being asymptomatic, the patient exhibited sinus bradycardia, which resolved upon discontinuation of favipiravir. Favipiravir has been associated with QT prolongation and sinus bradycardia, though the exact mechanisms remain unclear. Our case adds to the growing body of evidence highlighting the potential cardiac complications of favipiravir therapy in COVID-19 patients. Further research is warranted to clarify the underlying mechanisms and optimize patient management strategies. Clinicians should be cautious for cardiac adverse events when prescribing favipiravir for COVID-19 treatment, especially in patients with preexisting cardiac conditions. Continued research is essential to ensure the safe and effective use of favipiravir in the management of COVID-19.