The U.S. Food and Drug Administration has permitted limited use of the antimalarial drugs hydroxychloroquine and chloroquine in the treatment of COVID-19 since issuing an Emergency Use Authorization for such drugs on March 28, 2020.  On April 24, 2020, FDA issued an FDA Drug Safety Communication "caution[ing] against use of hydroxychloroquine or chloroquine for COVID-19 outside of the hospital setting or a clinical trial due to risk of heart rhythm problems," and strongly recommended close supervision during treatment.  An FDA website breaks down the Communication into its main sections and provides contact information for obtaining more information and how to report serious medical problems relating to treatment. 

In the Communication, FDA announced it is aware of reports of "serious heart rhythm problems," and in some cases death, in COVID-19 patients treated with hydroxychloroquine and chloroquine.  The problems arose with treatments of hydroxychloroquine or chloroquine alone as well as treatments combining such drugs with azithromycin,1 an antibiotic, or other medicines that also affect heart rhythm.  FDA also noted an increase in outpatient prescriptions for hydroxychloroquine and chloroquine. 

The Communication addresses FDA concerns about treatment of COVID-19 with hydroxychloroquine and chloroquine, and, in particular, treatment without close monitoring.  To decrease the risks of the heart-related side effects, FDA warns the public that the use of these drugs, whether alone or in combination with azithromycin, to treat COVID-19 should be limited to clinical trials or for treating certain hospitalized patients .  FDA further includes reminders that health care providers should be aware of the known heart-related risks2 associated with hydroxychloroquine and chloroquine and that patients with heart and kidney disease are at increased risk of these life-threatening side effects.  Via the Communication, FDA recommends monitoring cardiac rhythms, electrolytes, and renal functions in patients treated with hydroxychloroquine and chloroquine.

The Communication also a provides a series of statements reflecting the current research on COVID-19 therapies and the use of hydroxychloroquine and chloroquine in treating COVID-19 in particular.  Specifically, FDA cautions:

  • There are "no proven treatments for COVID-19 and no vaccine;"
  • Hydroxychloroquine and chloroquine are not approved by FDA to treat COVID-19;3
  • Neither hydroxychloroquine nor chloroquine has been shown to be safe and effective for the treatment or prevention of COVID-19;
  • The EUA permitting use of hydroxychloroquine and chloroquine was for use only in hospitalized patients undergoing careful heart monitoring;
  • The EUA was based upon "limited evidence" that the drugs could provide a benefit, e.g., anecdotal evidence of patients improving with treatment where there was no control group and laboratory testing showing inhibition of virus growth;
  • The public should not buy hydroxychloroquine or chloroquine from online pharmacies without a prescription or take the drugs in any form that has not been prescribed for them, such as veterinary products containing chloroquine.

As the COVID-19 crisis evolves, Seyfarth Shaw attorneys are closely monitoring COVID-19 related treatments and preventive measures described by FDA and other government agencies.  We are available to protect your interests, help you mitigate risks and liabilities, and keep you informed regarding the latest implications related to the COVID-19 crisis. Visit our Resource Center for more information.


1   Azithromycin also has not been approved by the FDA for the treatment or use in COVID-19 patients, as noted in the Communication

2   Specifically, hydroxychloroquine and chloroquine causes "QT interval prolongation," i.e., the heart muscle takes longer to recharge between beats, and ventricular tachycardia, i.e., a dangerously rapid heart rate condition.  Other side effects also may occur, such as low blood sugar, anemia, neurological issues, and potential vision problems, all of which FDA noted in a Q&A relating to its EUA for hydroxychloroquine and chloroquine.

3  Currently, the only approved uses are for the treatment of malaria (hydroxychloroquine sulfate and certain chloroquine phosphate compounds) and for the treatment of lupus and rheumatoid arthritis (hydroxychloroquine sulfate).

Originally published by Seyfarth Shaw, April 2020

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