COVID-19 News

CDC warns against using nonpharmaceutical chloroquine phosphate

The Centers for Disease Control and Prevention (CDC) issued a warning on March 28 about the dangers of using nonpharmaceutical chloroquine phosphate to prevent or treat COVID-19, and emphasized that even the pharmaceutical formulations of chloroquine are not yet known to have any benefits related to the current coronavirus pandemic.

The warning was issued following two cases of individuals who ingested nonpharmaceutical chloroquine phosphate, a chemical for aquarium use that is commercially available for purchase at stores and through internet websites. One of the individuals died shortly after arrival to the hospital. The second individual was critically ill with severe gastrointestinal symptoms and cardiac conduction abnormalities. Upon recovery, the surviving individual reported to the media that they ingested the product to prevent infection with SARS-CoV-2, which causes coronavirus disease 2019 (COVID-19), after seeing information on the medical use of chloroquine on television.

Pharmaceutical chloroquine phosphate and hydroxychloroquine sulfate are approved by the US Food and Drug Administration (FDA) to treat specific medical conditions, such as malaria, lupus, and rheumatoid arthritis. Currently, these medications are being studied and evaluated as treatment for COVID-19; however, their efficacy to either prevent or treat this infection are unknown, the CDC wrote. Chloroquine phosphate has a narrow therapeutic index—it can be toxic at levels not much higher than those used for treatment—which raises the risk of inadvertent overdose.

Public interest in chloroquine for treating COVID-19 has been focused on a small French study cited by President Trump in urging for further study of the drug's potential in combination with the antibiotic azithromycin. Numerous scientists, however, have pointed to that study's methodological limitations and the risk that treatment could do more harm than good. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID) said last week that information on malaria drugs combined with antibiotics remains "anecdotal" and needs to be evaluated in a clinical study.

Read the CDC's warning:

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