Hydroxychloroquine, Chloroquine, and COVID-19

Apr 20, 2020 | Clinical Insight

The Search for a Treatment of Coronavirus

Currently, there are no FDA approved drugs specifically for the treatment of COVID-19.Hydroxychloroquine sulfate and Chloroquine Phosphate have shown activity in laboratory studies against coronaviruses, including SARS-CoV-2 (the virus that causes COVID-19). Anecdotal reports suggest that these drugs may offer some benefit in the treatment of hospitalized COVID-19 patients. Available data is limited, however, and ongoing clinical trials are needed to provide scientific evidence that these treatments are effective. The FDA encourages the conduct and participation in randomized controlled clinical trials that may produce evidence concerning the effectiveness of these products in treating COVID-19.

Emergency Use Authorization (EUA) issued for the use of hydroxychloroquine and chloroquine.

On March 28, 2020, the FDA issued an Emergency Use Authorization (EUA) for the use of hydroxychloroquine and chloroquine to treat COVID-19 patients. The EUA permits the emergency use of hydroxychloroquine sulfate and chloroquine phosphate supplied from the Strategic National Stockpile to treat adults and adolescents who weigh 50 kg or more and are hospitalized with COVID-19 for whom a clinical trial is not available, or participation is not feasible. The optimal dosing and duration of treatment for these medications for COVID-19 is unknown. Dosing and duration may be updated as data from clinical trials becomes available.

Hydroxychloroquine Sulfate (Plaquenil)

Hydroxychloroquine Sulfate (Plaquenil) is an oral disease-modifying antirheumatic drug (DMARD). Currently, it is FDA approved to treat rheumatoid arthritis, systemic lupus erythematosus, and malaria in the United States.

  • Suggested dosing under the EUA for Hydroxychloroquine for COVID-19: 800 milligrams orally of hydroxychloroquine sulfate on the first day of treatment and then 400 milligrams daily for four to seven days of total treatment based on clinical evaluation.

Chloroquine phosphate (Aralen)

Chloroquine phosphate (Aralen) is an oral antiprotozoal agent FDA approved for the treatment and prophylaxis of susceptible malaria strains and for the treatment of extraintestinal amebiasis.

  • Suggested dosing under the EUA for Chloroquine phosphate for COVID-19: 1 gram of chloroquine phosphate on day one, followed by 500 milligrams daily for four to seven days of total treatment based on clinical evaluation.

The safety profile of Hydroxychloroquine and Chloroquine has only been studied for FDA approved indications, not COVID-19.


  • Retinal or visual field changes of any etiolog
  • Patients with known hypersensitivity to 4-aminoquinoline compounds
  • They should not be used in patients with a prolonged QT interval at baseline or at increased risk for arrythmia

Warnings/Adverse effects:

  • Cardiac:
    • QT prolongation/Ventricular arrhythmias: Use with caution in patients with cardiac disease, QT prolongation, a history of ventricular arrhythmias, bradycardia, uncorrected potassium or magnesium imbalance, and during concomitant administration with QT interval prolonging drugs such as azithromycin and some other antibacterial drugs. Monitor the electrocardiogram during treatment. See DYK from August 2018 on medications and QT prolongation (PDF). For a complete list of medications that carry a known risk, possible risk or conditional risk for QT Prolongation, please visit: https://www.crediblemeds.org/
    • Cardiomyopathy that can be life-threatening
      • Severe, life-threatening hypoglycemia in patients treated with or without antidiabetic medications.
      • Adverse hematologic effects including anemia, leukopenia, neutropenia, thrombocytopenia.
      • CNS adverse effects including psychosis, hallucinations, confusion, and agitation can occur. They may increase the risk of seizures in those with a history of seizures.
      • Irreversible retinal damage.
      • Use cautiously in patients with renal and hepatic impairment as they can increase risk of toxicities associated with these medications.
      • Can exacerbate psoriasis.

Recommended Laboratory and Monitoring Procedures:

  • A baseline electrocardiogram should be obtained to assess for QT interval prolongation and other abnormalities.
  • Baseline evaluation of renal and hepatic function is recommended.

Fact sheets regarding the use chloroquine phosphate and hydroxychloroquine sulfate in treating COVID-19

The EUA requires that fact sheets that provide important information about using chloroquine phosphate and hydroxychloroquine sulfate in treating COVID-19 be made available to health care providers and patients, including the known risks and drug interactions.

The prescribing health care provider and/or the provider’s designee are/is responsible for reporting medication errors and adverse events (death, serious adverse events*) occurring during hydroxychloroquine sulfate treatment within 7 calendar days from the onset of the event.

Regarding dispensing in NYS: Any person authorized to prescribe such medications must note on the prescription the condition for which such prescription has been issued. Days supply dispensed of hydroxychloroquine and chloroquine must match the quantity required by the prescription or medication order, as long as the prescription or medication order is compliant with these guidelines and the amount requested to be dispensed falls within normal treatment guidelines for the FDA-approved indication.


  1. https://www.hhs.gov/about/news/2020/03/29/hhs-accepts-donations-of-medicine-to-strategic-national-stockpile-as-possible-treatments-for-covid-19-patients.html
  2. https://dailymed.nlm.nih.gov/dailymed/
  3. www.fda.gov
  4. https://www.crediblemeds.org/

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Brandi VanValkenburg

Brandi provides personalized care as a pharmacy consultant with HealthDirect's northeastern region.  She has been serving our clients for over 10 years. 

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