Hydroxychloroquine, a drug that has existed for several decades, could see a resurgence of demand, after the Indian Council of Medical Research (ICMR) on Monday recommended its use as a post-exposure prophylactic (preventive medicine) against the novel coronavirus disease.
Last week, US President Donald Trump had said a hydroxychloroquine-azithromycin combination could be a “game changer” in the fight against COVID-19.
What is known about hydroxychloroquine’s efficacy in COVID-19 patients?
Hydroxychloroquine (not to be confused with anti-malaria drug chloroquine) is an oral drug used in the treatment of autoimmune diseases such as rheumatoid arthritis. On March 19, an article in The Lancet Global Health explored its therapeutic and prophylactic properties. “Notably, the drug shows antiviral activity in vitro against coronaviruses, and specifically, SARS-CoV-2 [the virus that causes COVID-2]. Pharmacological modelling based on observed drug concentrations and in vitro drug testing suggest that prophylaxis with hydroxychloroquine at approved doses could prevent SARS-CoV-2 infection and ameliorate viral shedding.” It also mentioned clinical trials currently under way in China on whether the drug can be used for treatment.
HYDROXYCHLOROQUINE & AZITHROMYCIN, taken together, have a real chance to be one of the biggest game changers in the history of medicine. The FDA has moved mountains – Thank You! Hopefully they will BOTH (H works better with A, International Journal of Antimicrobial Agents)…..
— Donald J. Trump (@realDonaldTrump) March 21, 2020
In a note for physicians on the therapeutic options for COVID-19, the US Centers for Disease Control and Prevention (CDC) says: “Hydroxychloroquine is currently under investigation in clinical trials for pre-exposure or post-exposure prophylaxis of SARS-CoV-2 infection, and treatment of patients with mild, moderate, and severe COVID-19. In the United States, several clinical trials of hydroxychloroquine for prophylaxis or treatment of SARS-CoV-2 infection are planned or will be enrolling soon.”
The CDC says both hydroxychloroquine and chloroquine have in vitro activity against SARS-CoV, SARS-CoV-2, and other coronaviruses, with hydroxychloroquine having higher potency against SARS-CoV-2. “A study in China reported that chloroquine treatment of COVID-19 patients had clinical and virologic benefit versus a comparison group, and chloroquine was added as a recommended antiviral for treatment of COVID-19 in China…”
What has India recommended?
The National Taskforce for COVID-19 has recommended hydroxychloroquine for prophylaxis in case of asymptomatic healthcare workers involved in the care of suspected or confirmed cases of COVID-19 and asymptomatic household contacts of laboratory confirmed cases. The new guidelines say: “Hydroxy-chloroquine is found to be effective against coronavirus in laboratory studies and in-vivo studies. Its use in prophylaxis is derived from available evidence of benefit as treatment and supported by pre-clinical data… The following recommendation… is based on these considerations, as well as risk-benefit consideration, under exceptional circumstances that call for the protection of high-risk individuals.”
Doctors in the private sector are, however, cautious. “ICMR guidelines are very specific for specific people. We have to limit it to them. It cannot become something that everybody uses,” said Dr S Chatterjee, consultant at Indraprastha Apollo Hospitals.
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“As infection spreads there would be many more cases maybe for the next couple of months. You cannot give chloroquine and hydroxychloroquine to anybody and everybody… We don’t know whether it is effective, we are only extrapolating available data. Also if it becomes something everybody takes, there would be stock issues too… Let more evidence emerge on its efficacy before we take a call,” Dr Chatterjee said.
So should you stock the drug?
The short answer is, no. If you suspect you have contracted the infection, you should visit a doctor. You must not attempt to self-medicate. Even the government’s guidelines on hydroxychloroquine say the drug has to be given only on the prescription of a registered medical practitioner.
What combination did Trump speak of?
The combination is hydroxychloroquine with azithromycin, a commonly used antibiotic. On Saturday, following a press conference in which he endorsed the combination, Trump tweeted: “HYDROXYCHLOROQUINE & AZITHROMYCIN, taken together, have a real chance to be one of the biggest game changers in the history of medicine. The FDA has moved mountains – Thank You!…”
While the roles of chloroquine and hydroxychloroquine in management of COVID-19 are still open questions for the scientific community, the azithromycin-hydroxychloroquine combination is part of an upcoming multicountry trial anchored by the WHO in the fight against COVID-19.
The azithromycin-hydroxychloroquine combination has sometimes been administered to COVID-19 patients in the US, the CDC says. In a small study in the International Journal of Antimicrobial Agents published on March 17, French scientists reported: “Twenty cases were treated in this study and showed a significant reduction of the viral carriage at D6-post inclusion compared to controls, and much lower average carrying duration than reported of untreated patients in the literature. Azithromycin added to hydroxychloroquine was significantly more efficient for virus elimination.”
Simply put, the combination did reduce the viral load but the size of the study is too small to draw a definitive conclusion.
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