7 Things to Know About Hydroxychloroquine

Medically Reviewed By William C. Lloyd III, MD, FACS
Written By Karon Warren on August 4, 2020
  • doctor holding hydroxychloroquine drug
    Hydroxychloroquine Facts You Should Know
    Also known as Plaquenil, hydroxychloroquine is used to treat malaria, lupus, and acute and chronic rheumatoid arthritis. Hydroxychloroquine has received attention as a possible COVID-19 treatment too. While it has been used as an emergency treatment for select COVID-19 patients, the FDA (Food and Drug Administration) recently revoked Emergency Use Authorization for hydroxychloroquine. Compared to the beginning of the coronavirus outbreak, there is more information regarding the safety and effectiveness of hydroxychloroquine as a COVID-19 treatment. Find out what is known about hydroxychloroquine's use to fight malaria, why it's prescribed for lupus, and possible hydroxychloroquine side effects.
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    1. Hydroxychloroquine is thought to disrupt cell communications.
    Available in a tablet, hydroxychloroquine is classified as a disease-modifying antirheumatic drug, or DMARD. While it’s unknown exactly why the drug effectively treats autoimmune diseases like rheumatoid arthritis, it is thought to interfere with the communication of cells in the immune system. DMARDS help immune cells stick to their original task instead of aiding a harmful disease or virus to take over. It also has been shown to reduce pain and swelling caused by arthritis, and could prevent joint damage.
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    2. Hydroxychloroquine is prescribed as a preventive medication for malaria.
    A member of antimalarial drugs, hydroxychloroquine is used to prevent malaria. When traveling to countries where malaria is common, you can get a prescription to take hydroxychloroquine before, during and after the trip. The dosage is small, with one dose per week starting one week prior to the trip, one dose per week during the trip, and one dose per week for four weeks following the trip. However, hydroxychloroquine is not effective in all countries where malaria is common; the Centers for Disease Control and Prevention maintains an updated list of locations where this drug is recommended for use.
  • woman in bathrobe taking vitamins or medication
    3. Hydroxychloroquine also is used to treat lupus and rheumatoid arthritis.
    As early as 1834, antimalarial drugs were used in the treatment of lupus. In 1956, the FDA approved hydroxychloroquine as a therapeutic for both systemic lupus and rheumatoid arthritis. In particular, for lupus, it was shown to be effective in reducing the number of disease flares, reducing long-term damage, and delaying ultraviolet light absorption (photosensitivity is common among people with lupus). With regard to rheumatoid arthritis, hydroxychloroquine can decrease pain and swelling, prevent joint damage, and decrease the risk of long-term disability.
  • Man on couch with stomach pain
    4. Side effects of hydroxychloroquine include nausea and diarrhea.
    As with most medications, hydroxychloroquine can have unwanted side effects. With this drug, the most common side effects are stomach pain, nausea, vomiting, cramps, diarrhea and headache. Although not as common, some patients experience itching, rash, changes in skin pigment, muscle weakness, and/or hair changes. For many patients, taking hydroxychloroquine with food can greatly reduce these side effects. However, patients should consult their doctors if they experience more serious side effects, such as low blood sugar, fainting, blurred vision, irregular heartbeats, and ringing in the ears.
  • Female African American doctor showing prescription bottle to older Caucasian female patient
    5. Pre-existing conditions and hydroxychloroquine may not go together well.
    Because hydroxychloroquine can cause visual changes or loss of vision, it’s important for patients who have existing eye problems, especially those involving the retina, to discuss taking this drug with their doctor. Patients with diabetes, psoriasis, kidney disease, liver disease, blood or bone marrow problems, muscle problems, stomach or bowel problems, and/or nerve problems also should consult with their physician before taking hydroxychloroquine. In addition, there is always the possibility of adverse drug interactions, so it’s imperative to talk with your doctor to see if this drug will lead to problems if taken with your current medications.
  • two doctors in hospital looking at digital tablet
    6. Hydroxychloroquine effectiveness in treating COVID-19 is not consistent.
    Although there is no FDA-approved treatment for COVID-19, hydroxychloroquine was administered to certain patients hospitalized with the coronavirus. A small study of 62 patients conducted at the Renmin Hospital of Wuhan University in China, the researchers found that hydroxychloroquine significantly shortened body temperature recovery time and cough remission time, plus improved pneumonia.

    Based upon early promising results for hydroxychloroquine, the FDA granted Emergency Use Authorization (EUA) for its use in certain patients hospitalized COVID-19 who are not eligible for a clinical trial. However, the positive effect of hydroxychloroquine on COVID-19 recovery was not consistent overall. That fact, in combination with potentially serious side effects, prompted the FDA to pull the EUA for hydroxychloroquine. Doctors should not treat COVID-19 patients with hydroxychloroquine unless they are part of a hydroxychloroquine clinical trial.
  • woman consoling husband
    7. Unsupervised consumption of hydroxychloroquine could have serious consequences.
    Because treatment of COVID-19 using hydroxychloroquine is still experimental, no one should take this drug without the supervision and administration of their doctor. In fact, you should not obtain hydroxychloroquine without a prescription. The CDC advises against trying to purchase this drug overseas because the medications you receive may be of poor quality, contaminated or counterfeit. In addition, the National Capital Poison Center advises everyone to talk to a trusted healthcare provider or Poison Control to fight misinformation that could lead to serious consequences, such as taking chloroquine in other forms that could be fatal.
7 Things to Know About Hydroxychloroquine

About The Author

A graduate of the University of Southern Mississippi, Karon is a successful long-time published journalist who covers health, finance, insurance, business, real estate, lifestyle and travel. Her work appears in numerous online outlets and print publications across the country. She also is a member of the American Society of Journalists and Authors.
  1. Fact Sheet for Patients and Parent/Caregivers Emergency Use Authorization (EUA) of Hydroxychloroquine Sulfate for Treatment of Covid-19 in Certain Hospitalized Patients. Food and Drug Administration. https://www.fda.gov/media/136538/download
  2. Hydroxychloroquine (Plaquenil). American College of Rheumatology. https://www.rheumatology.org/I-Am-A/Patient-Caregiver/Treatments/Hydroxychloroquine-Plaquenil
  3. Medicines for the Prevention of Malaria While Traveling: Hydroxychloroquine (Plaquenil). Centers for Disease Control and Prevention. https://www.cdc.gov/malaria/resources/pdf/fsp/drugs/hydroxychloroquine.pdf
  4. Hydroxychloroquine: Benefits, Side Effects and Dosing. Lupus Foundation of America. https://www.lupus.org/resources/drug-spotlight-on-hydroxychloroquine#
  5. Drugs and Supplements: Hydroxychloroquine (Oral Route). Mayo Clinic. https://www.mayoclinic.org/drugs-supplements/hydroxychloroquine-oral-route/description/drg-20064216
  6. Efficacy of Hydroxychloroquine in Patients with COVID-19: Results of a Randomized Clinical Trial. MedRxiv.org. https://www.medrxiv.org/content/10.1101/2020.03.22.20040758v2
  7. Chloroquine and Hydroxychloroquine Can Have Serious Side Effects. National Capital Poison Center. https://www.poison.org/articles/chloroquine-hydroxychloroquine
  8. Emergency Use Authorization. U.S. Food and Drug Administration. https://www.fda.gov/emergency-preparedness-and-response/mcm-legal-regulatory-and-policy-framework/emergency-use-authorization#coviddrugs
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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2020 Jun 17
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.