Mayo Clinic cardiologist: 'Inexcusable' to ignore hydroxychloroquine side effects

WASHINGTON — As the U.S. scales up purchase and use of the drug hydroxychloroquine to treat coronavirus patients, a leading Mayo Clinic cardiologist is sounding a warning: Anyone promoting the drug also needs to flag its rare but serious — and potentially fatal — side effects. President Donald Trump has repeatedly touted the potential benefits of hydroxychloroquine, which has been approved by the Food and Drug Administration to treat malaria, lupus and other autoimmune ailments but hasn't yet been proven effective and safe in treating the coronavirus . Trump asked Saturday at the White House when pressed by reporters about hydroxychloroquine's effectiveness. After observing the debate over hydroxychloroquine on TV news and in social media, Dr. Michael Ackerman, a genetic cardiologist who is director of the Mayo Clinic's Windland Smith Rice Genetic Heart Rhythm Clinic, took the unusual step in late March of issuing guidance for physicians . Ackerman and his Mayo Clinic colleagues created a cardiac algorithm, published in Mayo Clinic Proceedings, to help physicians more safely prescribe hydroxychloroquine by identifying patients at greatest risk for drug-induced sudden cardiac death. In fact, a small recent study showed that up to 11 percent of coronavirus patients on hydroxychloroquine and azithromycin are in the so-called "red zone" for potential cardiac side effects. Prescribing physicians must assess individual patient risk by establishing the so-called QTc interval — an indicator of the health of the heart's electrical recharging system, Ackerman said. A patient with a significantly prolonged QTc is at increased risk for severe disturbances of the heart's electrical system that can lead to sudden cardiac death. Download the NBC News app for full coverage and alerts about the coronavirus outbreak Hydroxychloroquine's fate as an FDA-approved drug to treat the coronavirus remains uncertain, Ackerman added.