Medications for rate control
Most β-blockers can be safely used with investigational COVID-19
medications. Verapamil is P-glycoprotein (P-gp) related and metabolized
by CYP3A4-type cytochrome P450-dependent enzymes (Table 2). Since HCLQ
exerts impact on hyperpolarization-activated current Ifmodulation in sinoatrial node and atrioventricular node cells,
co-administration of verapamil and HCLQ may cause bradycardia and
conduction disturbance.37Digoxin is well-known for its
narrow therapeutic range.38Moreover, investigational
COVID-19 medications which consist of substrate of CYP3A4 and P-gp, such
as HCLQ, may potentially increase digoxin level and its toxicity,
resulting in conduction disturbance.39Therefore, ECG
monitoring for bradycardia and conduction disturbance should be
considered.