key: cord-1029759-em8wchd1 authors: Kumar, Satarupa; Sil, Abheek; Das, Anupam title: Hydroxychloroquine for COVID‐19: Myths vs Facts date: 2020-06-17 journal: Dermatol Ther DOI: 10.1111/dth.13857 sha: edbbd5a3335c2f53b092c58e642a2ab042f7bc14 doc_id: 1029759 cord_uid: em8wchd1 nan Hydroxychloroquine is the β-hydroxylated analogue of chloroquine which has garnered unprecedented attention as a potential drug for COVID-19, following preliminary reports on its in vitro activity against the virus. Hydroxychloroquine (EC50 = 0.72 μM) was found to be more potent than chloroquine (EC50 = 5.47 μM) in vitro against SARS-CoV-2. 1 By contrast, Liu et al found a lower EC50 for hydroxychloroquine with a similar 50% cytotoxic concentration for both the drugs. This article is protected by copyright. All rights reserved. mg BD for 4 days for the treatment of COVID-19. 1 Nonetheless, this dosing regimen should be interpreted with caution since a 95% confidence interval for the estimate of the EC50 was not provided. The Indian Council of Medical Research has recommended chemo-prophylaxis with hydroxychloroquine (400 mg twice on day 1, and then 400 mg once a week thereafter) for asymptomatic frontline workers and household contacts of confirmed cases. 5 In a cross-sectional study carried out among 140 doctors taking hydroxychloroquine prophylaxis for COVID-19, 44 participants (31%) reported adverse effects; most frequent symptoms being headache followed by nausea, dizziness, abdominal cramps, and diarrhoea. Hypoglycemia was seen in three participants with diabetes. 9 Gastrointestinal effect appears to be dose-dependent and most often occurs with loading doses ≥ 800 mg. Across the world, there have been several reports of overdoses in people self-medicating with hydroxychloroquine during the current pandemic. From the safety point of view, short-term hydroxychloroquine treatment has been considered safe, even in pregnancy. WHO has re-initiated the hydroxychloroquine arm of its solidarity trial which was previously suspended after a study published in the Lancet raising warnings about the drug's safety. 10 The study is now retracted. The incidence of QTc prolongation in the setting of hydroxychloroquine use is largely limited to case reports of chronic use. It is highly dependent on baseline ECG findings; risk being exacerbated with concomitant QTc-prolonging medications. Considering that COVID-19 itself This article is protected by copyright. All rights reserved. can have cardiac manifestations, periodic QT interval should be monitored in COVID-19 patients on hydroxychloroquine. Although some of the clinical studies have shown a good effectiveness of hydroxychloroquine in achieving virological and clinical endpoints in patients with COVID-19, they have had some major limitations with high risk of bias, varied dosing protocols and short treatment periods. Hence, the factual clinical benefit of hydroxychloroquine in COVID-19 is still elusive. Finally, pharmacovigilance on its potentially serious adverse effects is also required. In Vitro Antiviral Activity and Projection of Optimized Dosing Design of Hydroxychloroquine for the Treatment of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Hydroxychloroquine, a less toxic derivative of chloroquine, is effective in inhibiting SARS-CoV-2 infection in vitro Efficacy of hydroxychloroquine in patients with COVID-19: results of a randomized clinical trial Early treatment of COVID-19 patients with hydroxychloroquine and azithromycin: a retrospective analysis of 1061 cases in Trav Med Infect Dis. 2020 Hydroxychloroquine in patients with COVID-19: an open-label, randomized This article is protected by copyright. All rights reserved No evidence of rapid antiviral clearance or clinical benefit with the combination of hydroxychloroquine and azithromycin in patients with severe COVID-19 infection No evidence of clinical efficacy of hydroxychloroquine in patients hospitalized for COVID-19 infection with oxygen requirement: results of a study using routinely collected data to emulate a target trial Adverse drug reaction profile of prophylactic hydroxychloroquine for COVID-19 among doctors WHO Resumes Hydroxychloroquine Study For Covid-19 This article is protected by copyright. All rights reserved