The COVID-19 pandemic has led to efforts at rapid investigation and application of drugs which may improve prognosis, but for which safety and efficacy are not yet established. This document attempts to provide reasonable guidance for use of antimicrobials which have uncertain benefit but may increase risk of QT prolongation and ventricular proarrhythmia, notably, chloroquine, hydroxychloroquine, azithromycin, and lopinavir/ritonavir. During the pandemic, efforts to reduce spread and minimize effects on health care resources mandate minimization of unnecessary medical procedures and testing. We recommend that the risk of drug proarrhythmia be minimized by: 1. discontinuing unnecessary medications which may also increase the QT interval, 2. identifying outpatients who are likely at low risk and do not need further testing (no history of prolonged QT, unexplained syncope or family history of premature sudden cardiac death, no medications which may prolong the QT interval, and/or prior known normal QTc), and 3. performing baseline testing in hospitalized patients or those who may be at higher risk. If baseline ECG testing reveals a moderately prolonged QTc, optimization of medications and electrolytes may permit therapy. If the QTc is markedly prolonged, drugs which further prolong it should be avoided, or expert consultation may permit administration with mitigating precautions. These recommendations are made while there are no known effective treatments for COVID-19 and should be revisited when further data on efficacy and safety becomes available.