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Review: Doubt Cast on Use of Chloroquine and Hydroxychloroquine for COVID-19

In This Article

  • Early anecdotal studies suggest that the drugs chloroquine and hydroxychloroquine may be effective against SARS-CoV-2 (COVID-19)
  • A newly published review by Mark Poznansky, MD, PhD, and colleagues point to flaws in these early studies that suggest the two drugs may impair a patient's response to the virus
  • The authors emphasize the need for caution in utilizing therapies involving these two drugs in the treatment of SARS-CoV-2

The drugs chloroquine and hydroxychloroquine were first introduced as treatments for malaria, rheumatoid arthritis and lupus. A new review led by Mark Poznansky, MD, PhD, director of the Vaccine and Immunotherapy Center in the Infectious Disease Division of Massachusetts General Hospital, published in The FASEB Journal, covers the science and clinical experiences of the two drugs in treating the SARS-CoV-2 virus.

The review aims to show aspects of the anti-viral and immune-modulatory activities of hydroxychloroquine that could potentially help or impair a patient's response to the virus.

Although earlier anecdotal reports and poorly controlled clinical trials initially raised optimism about the drugs in treating SARS-CoV-2, the authors present mechanistic reasons why these drugs may actually fail. To start, recent studies use data from lab-cultured cells, not patients. This early research also overlooked the powerful immunosuppressive action of the drugs and the fact that they have failed in previous respiratory virus outbreaks, including influenza.

The authors infer that the drugs inhibit innate immune reactions critical to viral defense, as well as the generation of adaptive, cell-mediated immunity that is also necessary to control a virus like SARS-CoV-2.

The authors emphasize the need for caution in utilizing therapies involving these drugs and believe that current clinical trial results point to a rapidly diminishing view of their efficacy in the pandemic.

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Recently, based on clinical data, the FDA and the NIH have each released formal statements expressing concern regarding the safety and efficacy of hydroxychloroquine and chloroquine. In his second Q&A on the subject, Raghu Chivukula, MD, PhD, gives an update on the use of these drugs to treat COVID-19.