Under study for COVID-19

Hydroxychloroquine and a related drug, chloroquine, have been under study as possible treatments for COVID-19 (the illness caused by the new coronavirus). However, the FDA has just revoked its emergency use authorization for these two drugs. This is because the drugs may not be effective in treating COVID-19, and their risks may outweigh their potential benefits for this use. Do not use these medications to treat COVID-19 unless your doctor recommends that you do so.

For current information about the COVID-19 outbreak, explore our live updates. And for information on how to prepare, advice on prevention and treatment, and expert recommendations, visit our COVID-19 hub.

  • Hydroxychloroquine oral tablet is available as a brand-name drug and a generic drug. Brand name: Plaquenil.
  • Hydroxychloroquine comes only as a tablet you take by mouth.
  • Hydroxychloroquine is used to treat malaria, lupus erythematosus, and rheumatoid arthritis.

  • Child danger warning: Accidentally swallowing just a few tablets has been fatal in some children. Keep this drug in a child-resistant bottle out of reach of children.
  • Worsened skin conditions warning: Tell your doctor if you have skin conditions, such as psoriasis or porphyria. This medication may make these conditions worse.
  • Eye damage: This medication can damage your eyes, leading to vision problems that can be permanent. This damage is more likely when the drug is used in high doses.
  • Heart damage: This medication can cause heart disease. Although uncommon, some cases have been fatal.

Hydroxychloroquine is a prescription drug. It comes as an oral tablet.

Hydroxychloroquine is available as the brand-name drug Plaquenil. It’s also available in a generic version. Generic drugs usually cost less than the brand-name version. In some cases, they may not be available in every strength or form as the brand-name drug.

Hydroxychloroquine may be used as part of a combination therapy. That means you may need to take it with other drugs.

Why it’s used

Hydroxychloroquine is used to treat lupus erythematosus and rheumatoid arthritis. It’s also used to prevent and treat malaria.

How it works

Hydroxychloroquine is an antimalarial drug. It treats malaria by killing the parasites that cause the disease.

It isn’t fully understood how this drug works to treat lupus erythematosus or rheumatoid arthritis. However, it’s believed that this drug affects how your immune system works, which may be a benefit in lupus erythematosus and rheumatoid arthritis.

Hydroxychloroquine oral tablet doesn’t cause drowsiness, but it can cause other side effects.

More common side effects

The more common side effects that can occur with hydroxychloroquine include:

Mild side effects may go away within a few days or a couple of weeks. Talk to your doctor or pharmacist if they’re more severe or don’t go away.

Serious side effects

Call your doctor right away if you have serious side effects. Call 911 if your symptoms feel life threatening or if you think you’re having a medical emergency. Serious side effects and their symptoms can include the following:

Suicide prevention

If you know someone at immediate risk of self-harm, suicide, or hurting another person:

  • Ask the tough question: “Are you considering suicide?”
  • Listen to the person without judgment.
  • Call 911 or the local emergency number, or text TALK to 741741 to communicate with a trained crisis counselor.
  • Stay with the person until professional help arrives.
  • Try to remove any weapons, medications, or other potentially harmful objects.

If you or someone you know is having thoughts of suicide, a prevention hotline can help. The National Suicide Prevention Lifeline is available 24 hours per day at 800-273-8255. During a crisis, people who are hard of hearing can call 800-799-4889.

Click here for more links and local resources.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this information includes all possible side effects. This information is not a substitute for medical advice. Always discuss possible side effects with a healthcare provider who knows your medical history.

Hydroxychloroquine oral tablet can interact with other medications, vitamins, or herbs you may be taking. An interaction is when a substance changes the way a drug works. This can be harmful or prevent the drug from working well.

To help avoid interactions, your doctor should manage all of your medications carefully. Be sure to tell your doctor about all medications, vitamins, or herbs you’re taking. To find out how this drug might interact with something else you’re taking, talk to your doctor or pharmacist.

Examples of drugs that can cause interactions with hydroxychloroquine are listed below.

Heart drug

Taking digoxin with hydroxychloroquine may increase the levels of digoxin in your body. This may increase your risk of side effects from digoxin.

Insulin and other diabetes drugs

Hydroxychloroquine and diabetes drugs all decrease your blood sugar level. Taking hydroxychloroquine with these drugs could cause hypoglycemia (low blood sugar). Your doctor may need to reduce your dosage of insulin or the other diabetes drugs.

Examples of other diabetes drugs include:

  • chlorpropamide
  • glipizide
  • glimepiride
  • glyburide
  • repaglinide

Drugs that affect heart rhythm

Hydroxychloroquine should not be taken with other drugs that could cause heart arrhythmias (irregular heart rate or rhythm). Taking hydroxychloroquine with these drugs could cause dangerous arrhythmias. Examples of these drugs include:

  • amiodarone
  • chlorpromazine
  • clarithromycin

Certain malaria drugs

Taking hydroxychloroquine with certain other malaria drugs can increase your risk of seizures. Examples of these drugs include:

  • mefloquine

Antiseizure drugs

Taking antiseizure drugs with hydroxychloroquine can make the antiseizure drugs less effective. Examples of these drugs include:

  • phenytoin
  • carbamazepine

Immunosuppressant drugs

Taking methotrexate with hydroxychloroquine has not been studied. It may increase your risk of side effects.

Taking cyclosporine with hydroxychloroquine can increase the amount of cyclosporine in your body. This may increase your risk of side effects from cyclosporine.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs interact differently in each person, we cannot guarantee that this information includes all possible interactions. This information is not a substitute for medical advice. Always speak with your healthcare provider about possible interactions with all prescription drugs, vitamins, herbs and supplements, and over-the-counter drugs that you are taking.

This drug comes with several warnings.

Allergy warning

Though rare, this drug may cause an allergic reaction. Symptoms can include:

  • hives
  • swelling
  • trouble breathing

If you develop these symptoms, call 911 or go to the nearest emergency room.

Don’t take this drug again if you’ve ever had an allergic reaction to it. Taking it again could be fatal (cause death).

Alcohol interaction warning

Alcohol misuse can damage your liver, which can affect how hydroxychloroquine works in your body. If you drink alcohol, ask your doctor about whether it’s safe for you to drink while taking hydroxychloroquine.

Warnings for people with certain health conditions

For people with skin problems: This drug may worsen the skin conditions psoriasis and porphyria.

For people with liver problems or alcohol misuse: Liver problems or a history of alcohol misuse can make this drug less effective.

For people with certain enzyme deficiencies: This drug may cause red blood cells to rupture (break open) in people with low levels of glucose-6-phosphate dehydrogenase (G6PD). G6PD is an enzyme, which is a type of protein.

Warnings for other groups

For pregnant women: This drug should be avoided in pregnancy. Some studies show that the medication can be passed through the mother’s bloodstream to the baby.

Talk to your doctor if you’re pregnant or plan to become pregnant. This drug should only be used during pregnancy if the potential benefit justifies the potential risk.

If you become pregnant while taking this drug, call your doctor right away.

For women who are breastfeeding: Small amounts of this drug pass through breast milk, but it’s not known what effect this may have on a child who is breastfed. You and your doctor should decide whether you’ll take this medication or breastfeed.

For seniors: This drug is processed by your kidneys. Older adults with reduced kidney function may not be able to process this drug well, which can increase the risk of side effects, including vision damage. Older adults may require more frequent eye exams while taking this drug to monitor for signs of vision damage.

For children: This drug can be dangerous to children. Accidentally swallowing even just a few tablets can lead to death in a small child. Keep this drug in a child-resistant bottle out of reach of children.

Children shouldn’t use this drug for long periods. Children taking this medication for a long period of time may experience permanent damage to their vision and other side effects.

All possible dosages and forms may not be included here. Your dose, form, and how often you take it will depend on:

  • your age
  • the condition being treated
  • how severe your condition is
  • other medical conditions you have
  • how you react to the first dose

Drug forms and strengths

Generic: Hydroxychloroquine

  • Form: oral tablet
  • Strength: 200 mg

Brand: Plaquenil

  • Form: oral tablet
  • Strength: 200 mg

Dosage for malaria

Adult dosage (ages 18 years and older)

  • Acute attack:
    • Typical starting dose is 800 mg. This is followed by 400 mg three times: 6 hours after the first dose, 24 hours after the first dose, and 48 hours after the first dose.
  • Prevention:
    • Typical dosage is 400 mg once per week, taken on the same day each week, starting 2 weeks before exposure to malaria.
    • Continue using this medication during exposure and for 4 weeks after leaving the area that has malaria.

Child dosage (ages 0–17 years)

  • Acute attack:
    • The typical starting dose is 13 mg/kg (maximum dose: 800 mg).
    • Additional doses of 6.5 mg/kg (maximum dose: 400 mg) should be given at the following times: 6 hours after the first dose, 24 hours after the first dose, and 48 hours after the first dose.
  • Prevention:
    • The dosage is based on body weight.
    • 6.5 mg/kg (maximum dose: 400 mg) should be given on the same day each week starting 2 weeks before exposure to malaria.
    • Your child should continue to use this medication during exposure and for 4 weeks after leaving the area that has malaria.

Dosage for lupus erythematosus

Adult dosage (ages 18 years and older)

  • Typical maintenance dosage: 200 mg to 400 mg per day, given as a single daily dose or in two divided doses.
  • Maximum dosage: 400 mg per day.

Child dosage (ages 0–17 years)

Dosage for children younger than 18 years hasn’t been established.

Dosage for rheumatoid arthritis

Adult dosage (ages 18 years and older)

  • Typical starting dosage: 400 mg to 600 mg per day, given as a single daily dose or in two divided doses.
  • Maintenance dosage:
    • When your body responds well to the medication, your doctor may lower your dosage to 200–400 mg per day, as a single daily dose or in two divided doses.
    • You may not see the best effect of this medication for several months.
    • Don’t take more than 600 mg per day or 6.5 mg/kg per day (whichever is lower). If you do, your risk of eye problems will increase.

Child dosage (ages 0–17 years)

Dosage for children younger than 18 years hasn’t been established.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this list includes all possible dosages. This information is not a substitute for medical advice. Always speak with your doctor or pharmacist about dosages that are right for you.

Hydroxychloroquine oral tablet is used for short-term treatment of malaria, but it may be used for long-term treatment of lupus erythematosus or rheumatoid arthritis.

Hydroxychloroquine comes with risks if you don’t take it as prescribed.

For malaria prevention: Start this medication 1 to 2 weeks before traveling to a country where malaria is present. Take it while you’re there, and continue to take it for 4 more weeks after you’ve left the area. Taking your medication as directed by your doctor will give you the best chance of not getting malaria.

For treating lupus erythematosus: Take your medication as directed by your doctor, even when you’re feeling well. This will give you the best chance of treating lupus and avoiding problems with your skin, joints, and other organs. It will also improve your quality of life.

For treating rheumatoid arthritis: Take your medication as directed by your doctor, even when you’re feeling well. This will help reduce swelling, pain, and stiffness in your joints and improve your quality of life.

What to do if you miss a dose: If you miss a dose, take the missed dose as soon as you can. However, if it’s almost time for the next scheduled dose, skip the missed dose and continue your regular dosing schedule.

Don’t take a double dose to make up for the missed one. You risk more serious side effects.

How to tell if the drug is working: For rheumatoid arthritis, you should have reduced joint inflammation, and you should be able to move better within 6 months of starting the medication.

For lupus erythematosus, you should have less joint swelling, less pain, fewer lupus-related rashes, and a better ability to move around.

For malaria, your fever should go away, and you should have less diarrhea and vomiting.

Keep these considerations in mind if your doctor prescribes hydroxychloroquine for you.

General

  • Do not crush, cut, or break hydroxychloroquine tablets.
  • Take each tablet with a meal or a glass of milk.
  • Take this drug at the time(s) recommended by your doctor. If you take this drug at times other than the ones prescribed, the level of the drug in your body could increase or decrease. If it increases, you could have more side effects. If it decreases, the drug might lose its effectiveness.
    • For treating malaria: Take this medication once weekly on the same day each week.
    • For treating lupus and rheumatoid arthritis: Take this medication at the same times every day for the best effect.

Storage

  • Store this medication at room temperature up to 86°F (30°C).
  • Keep the drug away from light and high temperatures.
  • Don’t store this medication in moist or damp areas, such as bathrooms.

Refills

A prescription for this medication is refillable. You should not need a new prescription for this medication to be refilled. Your doctor will write the number of refills authorized on your prescription.

Travel

When traveling with your medication:

  • Always carry your medication with you. When flying, never put it into a checked bag. Keep it in your carry-on bag.
  • Don’t worry about airport X-ray machines. They can’t harm your medication.
  • You may need to show airport staff the pharmacy label for your medication. Always carry the original prescription-labeled container with you.
  • Don’t put this medication in your car’s glove compartment or leave it in the car. Be sure to avoid doing this when the weather is very hot or very cold.

Clinical monitoring

Your doctor will examine you to check your health and make sure that you aren’t having side effects from your medication. The tests they may do include:

  • Eye exams. Your doctor may give you an eye exam when you start this drug and every 3 months while you’re taking it.
  • Reflex tests. Your doctor may test your knee and ankle reflexes and check you for muscle weakness if you’re on this medication long term.
  • Blood tests. Your doctor may order certain blood tests to monitor your health while you’re taking this medication.
  • Heart tests. Your doctor may order certain tests, such as an EKG, to monitor your heart while youre taking this medication.

Hidden costs

Beyond the cost of this drug, you may need to pay for additional eye exams and blood tests. The cost of these things will depend on your insurance coverage.

Prior authorization

Many insurance companies require a prior authorization for this drug. This means your doctor will need to get approval from your insurance company before your insurance company will pay for the prescription.

There are other drugs available to treat your condition. Some may be better suited for you than others. Talk to your doctor about other drug options that may work for you.

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or other healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.