Possible nirmatrelvir/ritonavir-induced bradycardia in a patient with asymptomatic COVID-19.

COVID-19 emerged in 2019 and was declared a pandemic by the World Health Organization in March 2020. COVID-19 is highly transmissible and can lead to bilateral pneumonia with severe respiratory failure. COVID-19 has led to more than 6.5 million deaths worldwide. The significant morbidity and mortality due to COVID-19 have resulted in the development of treatment modalities, such as novel antivirals, to reduce hospitalizations and progression of disease. In 2021, the US Food and Drug Administration authorized nirmatrelvir/ritonavir for emergency use in nonhospitalized patients with COVID-19. Nirmatrelvir is a newly developed protease inhibitor and is combined with a commonly used pharmacokinetic boosting agent, ritonavir. Given the novelty of nirmatrelvir/ritonavir, potential adverse effects remain uncertain. In this case, we describe a patient who was initiated on a course of nirmatrelvir/ritonavir and developed symptomatic bradycardia.