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Drug Profile

The information on this site is intended to supplement and enhance, not replace, the advice of a physician who is familiar with your medical history. Decisions about your health should always be made ONLY after detailed conversation with your doctor.

Generic drug name: hydroxychloroquine (hye drox ee KLOR oh kwin)
Brand name(s): PLAQUENIL
GENERIC: available FAMILY: Drugs for Arthritis and Gout
Find the drug label by searching at DailyMed.

Pregnancy and Breast-feeding Warnings [top]

Pregnancy Warning

Hydroxychlorquine rapidly crossed the placenta in an animal study and accumulated in fetal eyes; it remained there for five months after it had been removed from the rest of the body. Irreversible retinal damage has occurred in some patients taking this drug. Because of the potential for serious adverse effects to the fetus, this drug should not be used by pregnant women except for the treatment of malaria.

Breast-feeding Warning

There is no information on excretion of hydroxychloroquine in milk. However, because of the potential for serious adverse effects in nursing infants, you should not take this drug while nursing.

Facts About This Drug [top]

Hydroxychloroquine is used to treat malaria, rheumatoid arthritis and lupus erythematosus. Like other antiarthritis drugs, it reduces symptoms caused by inflammation. Because hydroxychloroquine has serious adverse effects, you should not be taking it for rheumatoid arthritis unless you have already tried other drugs that reduce inflammation and they have not worked.

Hydroxychloroquine takes time to produce results, and you may not notice improvement in your condition for weeks or months....

Hydroxychloroquine is used to treat malaria, rheumatoid arthritis and lupus erythematosus. Like other antiarthritis drugs, it reduces symptoms caused by inflammation. Because hydroxychloroquine has serious adverse effects, you should not be taking it for rheumatoid arthritis unless you have already tried other drugs that reduce inflammation and they have not worked.

Hydroxychloroquine takes time to produce results, and you may not notice improvement in your condition for weeks or months. Continue to take the drug as directed by your doctor, and use a nonsteroidal anti-inflammatory drug such as aspirin at the same time to relieve your symptoms until the hydroxychloroquine works. If the drug doesn’t begin to work after six months, it should be discontinued.

Hydroxychloroquine can cause serious adverse effects, some of which may occur months after you have stopped using it. Most troublingly, it rarely can cause QT prolongation, a change in the electrical activity of the heart that can lead to a life-threatening and often fatal abnormal heart rhythm.[1] The risk of QT prolongation is enhanced when the drug is combined with the antibiotic azithromycin (ZITHROMAX).[2] Hydroxychloroquine also may cause heart failure.

Hydroxychloroquine has also caused rash, hearing loss, muscle weakness and blood disorders. You should not take a dose greater than 400 milligrams per day, since taking such a large dose for a long time increases your risk of adverse effects.

Keep this drug out of the reach of children. Children are especially sensitive to the effects of hydroxychloroquine, and some have died after taking as few as three or four tablets.

In 2020 the Food and Drug Administration (FDA) and Health Canada (an agency in Canada similar to the FDA) issued a warnings that hydroxychloroquine can cause serious heart problems, including abnormal heart rhythms. The risk is increased when the drug is used together with azithromycin.[3],[4]

Before You Use This Drug [top]

Tell your doctor if you have or have had:

  • allergies to drugs
  • alcohol dependence
  • liver or kidney problems
  • severe blood disorders
  • gastrointestinal disease
  • glucose-6-phosphate dehydrogenase deficiency
  • disorders of the nervous system or seizures
  • psoriasis
  • eye disease
  • porphyria
  • pregnancy or are breast-feeding

Tell your doctor about any other drugs you take, including aspirin, herbs, vitamins, and other nonprescription products.

When You Use This Drug [top]

  • Do not drink alcohol.
  • Be alert to changes in vision and stop drug immediately. Hydroxychloroquine can cause irreversible damage to the eyes.
  • Have regular eye exams during and after long-term use.
  • Check with your doctor if there is no improvement in your arthritis after a few weeks or months. If there is no improvement in rheumatoid arthritis joint swelling or mobility after six months, the drug should be discontinued.
  • Until you know how you react to this drug, do not drive or perform other activities requiring alertness. Hydroxychloroquine causes lightheadedness and drowsiness.

How to Use This Drug [top]

  • If you miss a dose, use the following guidelines: If you take the drug once a week, take the missed dose as soon as you remember and resume your regular schedule. If you take the drug once a day, take the missed dose as soon as you remember, but skip it if you don’t remember until the next day. If you take the drug more than once a day, take the missed dose if you remember less than an hour after you were supposed to take it. If more than an hour has passed since you were supposed to take it, skip it. Continue to follow your regular schedule. Do not take double doses.
  • Take with food or milk to reduce stomach upset.
  • Store at room temperature with lid on tightly. Do not store in the bathroom. Do not expose to heat, moisture, or strong light. Keep out of reach of children.

Interactions with Other Drugs [top]

The following drugs, biologics (e.g., vaccines, therapeutic antibodies), or foods are listed in Evaluations of Drug Interactions 2003 as causing “highly clinically significant” or “clinically significant” interactions when used together with any of the drugs in this section. In some sections with multiple drugs, the interaction may have been reported for one but not all drugs in this section, but we include the interaction because the drugs in this section are similar to one another. We have also included potentially serious interactions listed in the drug’s FDA-approved professional package insert or in published medical journal articles. There may be other drugs, especially those in the families of drugs listed below, that also will react with this drug to cause severe adverse effects. Make sure to tell your doctor and pharmacist the drugs you are taking and tell them if you are taking any of these interacting drugs:

digoxin, FLAGYL, LANOXICAPS, LANOXIN, metronidazole.

Adverse Effects [top]

Call your doctor immediately if you experience:

  • changes of vision
  • seizures
  • mood or mental changes
  • hearing loss; ringing or buzzing in ears
  • unusual bleeding or bruising
  • unusual muscle weakness
  • sore throat and fever
  • fatigue, weakness

Call your doctor if these symptoms continue:

  • vision changes
  • diarrhea
  • loss of appetite
  • nausea, stomach cramps or pain
  • headache
  • itching
  • bleaching of hair or increased hair loss
  • blue-black discoloration of skin, fingernails, or inside mouth
  • dizziness or lightheadedness
  • nervousness or restlessness
  • skin rash

Call your doctor if this symptom continues after you stop taking this drug:

  • blurred vision or any change in vision

Signs of overdose:

  • difficulty breathing
  • drowsiness
  • fainting
  • seizure
  • coma
  • headache
  • very excitable

If you suspect an overdose, call this number to contact your poison control center: (800) 222-1222.

Periodic Tests[top]

Ask your doctor which of these tests should be done periodically while you are taking this drug:

  • eye exams (before use, and at least every six months during long-term use)
  • complete blood count
  • neuromusclar exams

last reviewed February 28, 2021