A 74-year-old Asian female with a history of hypertension and chronic obstructive pulmonary disease was admitted to hospital for coughing, shortness of breath and fatigue; her nasopharyngeal swab was positive for COVID-19. Lopinavir/ritonavir 800mg/200 mg, daily was started. On the third day of antiviral therapy, the patient complained of dizziness, nausea, she was disorientated, and electrocardiogram showed sinus arrest, junctional escape rhythm 36 beats per min. Patient was successfully treated by temporary pacemaker, normal sinus rhythm was reverted on a 3rd day after stopping the lopinavir/ritonavir treatment. She was discharged home in stable condition. Bradyarrhythmia in form of sinus arrest can develop during treatment with lopinavir/ritonavir. The temporal nature of the observed changes and the ECG finding suggests the use of L/R contributed to the changes. This case highlights off-label prescribing lopinavir/ritonavir outside of a clinical trial setting should be avoided until the data have proven that treatment benefit over placebo.