Key takeaways

  • Plaquenil can cause side effects ranging from mild issues like nausea and hair loss to more severe complications, including vision problems and heart issues.
  • Long-term use of Plaquenil increases the risk of eye-related side effects, like retinal damage, which can cause permanent vision loss. Regular eye exams are recommended to monitor and help prevent damage during Plaquenil treatment.
  • Certain conditions, such as heart problems or kidney issues, can raise the risk of experiencing serious side effects from Plaquenil. Be sure to discuss your full medical history with your doctor before starting Plaquenil treatment.

Plaquenil (hydroxychloroquine) is used in adults to:

Plaquenil is also used in certain children to treat and help prevent certain types of malaria.

Keep reading to learn about the common, mild, and serious side effects that Plaquenil can cause.

NOT USED FOR COVID-19

Hydroxychloroquine, the active drug in Plaquenil, is not recommended for use in treating COVID-19 (the illness caused by the coronavirus SARS-CoV-2). Do not take any prescription drug, including Plaquenil, unless your doctor recommends that you do so.

For information about how to prepare, advice on prevention and treatment, and expert recommendations, visit our coronavirus hub.

Some people may experience mild or serious side effects during Plaquenil treatment. Examples of Plaquenil’s most commonly reported side effects include:

Examples of mild side effects that have been reported with Plaquenil include:

For more information about some of these side effects, see the “Side effects explained” section.

In most cases, these side effects should be temporary. And some may be easily managed, too. But if you have any symptoms that are ongoing or that bother you, talk with your doctor or pharmacist. And don’t stop taking Plaquenil unless your doctor recommends it.

Plaquenil may cause mild side effects other than those listed above. See the Plaquenil prescribing information for details.

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Serious side effects that have been reported with Plaquenil include:

For more information about some of these side effects, see the “Side effects explained” section.

If you develop serious side effects while taking Plaquenil, call your doctor right away. If the side effects seem life threatening or if you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. Sharing your experience helps make medication safer for everyone by giving doctors and researchers more information about how the drug works in real life. If you develop a side effect while taking Plaquenil and want to tell the FDA about it, visit MedWatch or call 800-FDA-1088.

Allergic reaction

Like most drugs, Plaquenil can cause an allergic reaction in some people. But it’s not clear whether this side effect occurred in studies.

Symptoms may be mild or serious and can include:

  • skin rash
  • itchiness
  • flushing (temporary warmth, redness, or deepening of skin color)
  • swelling under your skin, typically in your eyelids, lips, hands, or feet
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, contact your doctor right away. To manage your symptoms, they may suggest an over-the-counter antihistamine you take by mouth, such as Benadryl (diphenhydramine). Or they may recommend a product you apply to your skin, such as hydrocortisone cream.

If your doctor confirms you had a mild allergic reaction to Plaquenil, they’ll determine if you should continue taking it.

If you have symptoms of a severe allergic reaction, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you had a serious allergic reaction to Plaquenil, they may have you switch to a different treatment.

Get answers to some frequently asked questions about Plaquenil’s side effects.

What are the rare side effects of Plaquenil?

It’s not fully known how often many of Plaquenil’s side effects occur. The drug’s prescribing information doesn’t list which side effects are rare. Plus, some side effects have been reported after the drug became available for use. This means it’s not fully known if the drug directly causes these side effects or how often they occur.

If you have questions about how often to expect certain side effects of Plaquenil, talk with your doctor or pharmacist.

Will I have side effects if I stop taking Plaquenil?

No, you should not have side effects or withdrawal symptoms when stopping Plaquenil treatment. Withdrawal symptoms are side effects that can happen when you stop taking a drug that your body is dependent on. (With dependence, your body needs the drug to feel like it usually does.)

Plaquenil isn’t known to cause drug dependence, so stopping it will not cause withdrawal symptoms.

However, if you take Plaquenil for lupus or rheumatoid arthritis, you may notice that stopping treatment may worsen your condition. This is because Plaquenil doesn’t cure these conditions, it only eases their symptoms. So stopping treatment can make your symptoms come back.

But if you take Plaquenil to treat or help prevent malaria, you won’t likely notice any problems after stopping treatment.

If you have questions about stopping treatment with Plaquenil, talk with your doctor.

Does my risk of side effects depend on the dose of Plaquenil I take (200 mg, 400 mg, or 600 mg)?

Possibly. As with many medications, taking high doses of Plaquenil may raise your risk of certain side effects. For example, taking higher doses of Plaquenil could raise your risk of certain eye-related and heart-related side effects. See the “Side effects explained” section to read more about these.

Ask your doctor what dosage of Plaquenil is recommended for your condition. They can tell you if this dosage has a higher risk of side effects than others.

Are there any side effects specific to taking Plaquenil for lupus?

No, there aren’t any side effects that are specific to people taking Plaquenil for lupus. But if you have lupus, you’ll likely need to take Plaquenil long term. And taking Plaquenil long term can raise your risk of certain side effects, such as retinal damage. To learn more, see the “Long-term side effects of Plaquenil” section.

Can Plaquenil cause weight gain?

No, it’s not likely. Weight gain isn’t a known side effect of this drug. In fact, Plaquenil may have the opposite effect. Loss of appetite and weight loss have been reported in some people taking Plaquenil. But it’s not known how often these side effects occur.

If you’re concerned about Plaquenil and weight gain or weight loss, talk with your doctor. They can suggest ways to help you reach or maintain a body weight that’s healthy for you.

Plaquenil can cause some long-term side effects. These are side effects that last for a long time or are permanent. The main long-term side effects of Plaquenil are eye-related.

Plaquenil can damage your retina, which may lead to permanent loss of vision. Retinal damage can get worse even after you stop taking the medication. Taking Plaquenil long term raises your risk of developing retinal damage. To read more about this side effect, see the “Side effects explained” section.

Some other serious side effects of Plaquenil, such as certain heart problems, may also last a long time, even with treatment.

Exactly how long side effects last will depend on how they respond to any treatments you may have for them. It’s not known if taking Plaquenil long term raises your risk of other side effects.

If you have questions about how long Plaquenil side effects may last, or your risk of having long-term side effects, talk with your doctor.

Learn more about some of the side effects Plaquenil may cause.

Eye-related side effects

It’s not known how often eye-related side effects happen with Plaquenil, but the drug can sometimes cause such side effects. These include damage to the retina, which is the light-sensitive tissue in the back of your eye. Damage to the retina can cause loss of vision that can be permanent.

Symptoms of retinal damage may include decreased vision or trouble seeing in the dark.

You may have an increased risk of retinal damage with Plaquenil if you:

  • take a high Plaquenil dosage
  • take the medication for longer than 5 years
  • have a disease affecting your macula (a small area in the center of your retina)
  • have kidney problems
  • take certain other medications

Other possible eye-related side effects of Plaquenil include macular degeneration and changes to the cornea, such as swelling or clouding. (The cornea is the front layer of your eye that lets in light.) These side effects can cause changes to your vision, such as blurry vision, double vision, halos around lights, and sensitivity to light. Plaquenil can also cause blind spots in your vision.

What might help

If you have any changes in your vision while taking Plaquenil or after stopping treatment, talk with your doctor right away. They’ll recommend having an eye exam. Eye exams check for any damage to your retina and other problems with your vision.

You should have an eye exam within 1 year of starting treatment with Plaquenil. During long-term treatment, you’ll then have more eye exams to check if your vision has changed since starting the drug. Eye exams are usually recommended every 5 years. But if you have an increased risk of retinal damage, these exams are recommended every year.

If you have certain eye side effects, in particular retinal damage, you’ll need to stop taking Plaquenil. And your doctor may switch you to a different treatment for your condition.

If you have retinal damage, your doctor will monitor you closely after you stop treatment. It’s possible the damage may continue, and your vision might continue to worsen.

If you’re concerned about the risk of eye-related side effects with Plaquenil, talk with your doctor.

Hair loss

Some people may have hair loss while taking Plaquenil. But it’s not known how often this side effect occurs.

Hair loss can also be a symptom of lupus and rheumatoid arthritis, which Plaquenil is prescribed to treat.

What might help

If you have hair loss while taking Plaquenil, talk with your doctor. They can help work out the cause of your hair loss and suggest ways to help manage it.

Dizziness

You might have dizziness while taking Plaquenil. But it’s not known how often this occurs.

It’s possible to have dizziness without any other symptoms. But dizziness can also be a symptom of other side effects of Plaquenil. These include ear-related side effects such as vertigo. With vertigo, you may also have nausea and a sensation of spinning.

Dizziness can also be a symptom of some serious side effects of Plaquenil, such as low blood sugar levels and heart problems.

What might help

If you have dizzy spells while taking Plaquenil, lie down until the dizziness eases. And be sure to get up slowly.

If you have dizziness that doesn’t ease, or if you often have dizzy spells, contact your doctor to get this checked. Your doctor can give further advice on what to do. They may also want to rule out more serious side effects.

Rash, itching, and severe skin-related side effects

It’s not known how often skin-related side effects happen with Plaquenil, but they can occur.

Plaquenil may cause a skin rash or itching. It may also make your skin more sensitive to sunlight or other UV light. This is called photosensitivity, and it can increase your risk of getting a sunburn.

Plaquenil may also cause serious skin-related side effects. These include Stevens-Johnson syndrome, toxic epidermal necrolysis, and drug reaction with eosinophilia and systemic symptoms (DRESS syndrome). These side effects can be life threatening.

Symptoms of serious skin-related side effects include:

  • blisters in the mouth or on the skin, eyes, or lips
  • itching
  • burning sensation
  • peeling
  • widespread rash
  • fever

What might help

While taking Plaquenil, it’s important to protect your skin from UV light to avoid getting a sunburn. You can do this by:

  • protecting your skin from sunlight with clothing
  • using sunscreen on skin that’s not covered
  • avoid using sunlamps and sunbeds

If you get a sunburn, rash, or itching while taking Plaquenil, talk with your doctor. They can recommend ways to manage these side effects. For example, they may suggest using a moisturizer or mild steroid cream or taking an antihistamine.

However, if you have symptoms of a serious skin-related side effect, contact your doctor right away. If your doctor diagnoses a serious skin reaction from Plaquenil, they’ll have you stop taking the medication.

Cardiac (heart-related) side effects

Plaquenil can sometimes cause heart-related side effects. These include cardiomyopathy (weakening of your heart muscle), heart failure, and irregular heart rhythm. These side effects can be life threatening, but it’s not known how often they occur.

You may have an increased risk of heart-related side effects with Plaquenil if you have:

Taking certain other medications may also increase your risk of these side effects.

Symptoms of heart-related side effects may include:

  • feeling that your heart is racing, pounding, or skipping beats
  • fast or irregular heartbeat
  • feeling dizzy or lightheaded
  • fainting
  • fatigue
  • shortness of breath
  • swollen ankles or feet

What might help

Before prescribing Plaquenil, your doctor will assess whether it’s safe for you to take. Talk with your doctor about any heart problems you may have. Also talk with them about any medications you take.

While taking Plaquenil, contact your doctor right away if you have any symptoms of heart-related side effects. But if your symptoms feel life threatening, call 911 or your local emergency number.

If your doctor confirms that you do have heart-related side effects from Plaquenil, they’ll have you stop taking the medication.

Before taking Plaquenil, discuss your health history with your doctor. Plaquenil may not be right for you if you have certain medical conditions or other factors affecting your health. Be sure to talk with your doctor if any of the following apply to you:

  • allergic reaction to Plaquenil or any of its ingredients
  • heart problems, including heart disease, such as heart failure, or a past heart attack
  • low levels of potassium or magnesium in your blood
  • kidney or liver problems
  • psoriasis or porphyria
  • blood disorders, such as anemia, neutropenia, or thrombocytopenia
  • deficiency of G6PD
  • diabetes
  • neurological disorders
  • alcohol consumption
  • pregnancy
  • breastfeeding
  • history of depression or other mental health problems

Help is out there

If you or someone you know is in crisis and considering suicide or self-harm, please seek support:

  • Call or text the 988 Suicide and Crisis Lifeline at 988 or chat at 988lifeline.org. Caring counselors are available to listen and provide free and confidential support 24/7.
  • Text HOME to the Crisis Text Line at 741741 to connect with a volunteer crisis counselor for free and confidential support 24/7.
  • Not in the United States? Find a helpline in your country with Befrienders Worldwide.
  • Call 911 or your local emergency services number if you feel safe to do so.

If you’re calling on behalf of someone else, stay with them until help arrives. You may remove weapons or substances that can cause harm if you can do so safely.

If you’re not in the same household, stay on the phone with them until help arrives.

Disclaimer: Healthline 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 another 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.