With no known treatment available for the novel coronavirus infections, hydroxychloroquine is being looked at as the potential solution for COVID-19, especially for alleviating pneumonia. However, emerging research is raising questions about the efficiency of this drug. One such recent study has found that the use of hydroxychloroquine in COVID-19 cases has shown an increased risk of cardiac arrhythmia.
Hydroxychloroquine is traditionally used as a malaria treatment. The possibility of it being used as a COVID-19 treatment emerges from the data from 2003 which found it to be effective against SARS-CoV-1, a viral infection that didn’t transmit as easily, but could prove fatal. Depending on the symptoms and intensity of the COVID-19 infections, the antimalarial drugs used in combination with azithromycin, an antibiotic.
The study, conducted by a team at the Beth Israel Deaconess Medical Center of Harvard Medical School, hydroxychloroquine used alone or in conjunction with azithromycin can lead to electrical disturbances in the heart. Also known as QTc prolongations, these disturbances can lead to cardiac arrhythmias in the patients, which could further increase the risk of cardiac arrest, stroke, and death.
“While hydroxychloroquine and azithromycin are generally well-tolerated medications, increased usage in the context of COVID-19 will likely increase the frequency of adverse drug events (ADEs),” said co-first author Nicholas J. Mercuro, PharmD, a pharmacy specialist in infectious diseases at BIDMC. “This is especially concerning given that patients with underlying cardiac co-morbidities appear to be disproportionately affected by COVID-19 and that the virus itself may damage the heart.”
The single-center, retrospective, observational study involved 90 subjects who were hospitalized at the BIDMC for COVID-19 and were given the antimalarial at least for a day. More than half of these subjects were dealing with high blood pressure, while over 30 percent had diabetes. 19 percent of patients who received hydroxychloroquine alone developed QTc prolongations of 500 milliseconds or more. Of the patients who received this with azithromycin, 21 percent showed prolongations of over 500 milliseconds.
Based on the risks of hydroxychloroquine use in COVID-19 patients with co-morbidities brought forth by this study, which has been published in the JAMA Cardiology, the researchers warn against its use as a solution. They recommend that the use of this drug against the novel coronavirus be limited to clinical trials.  
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