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 novel coronavirus). Do not take any prescription drug, including Plaquenil, 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.

Plaquenil (hydroxychloroquine) is a prescription brand-name medication. It’s approved by the Food and Drug Administration (FDA) to:

  • treat rheumatoid arthritis (an autoimmune condition that causes pain and swelling, primarily in and around your joints)
  • treat lupus (an autoimmune condition that causes pain and swelling in your body)
  • prevent or treat malaria (an infection spread by mosquitos that are found in tropical regions)

Plaquenil may be used for a short time or long-term, depending on the condition it’s taken for.

Here are some fast facts on Plaquenil:

  • Active ingredient: hydroxychloroquine
  • Drug class: anti-malarial
  • Drug form: oral tablet

Like other drugs, Plaquenil can cause side effects. Read on to learn about potential common, mild, and serious side effects. For a general overview of Plaquenil, including details about its limitations, see this article.

Plaquenil can cause certain side effects, some of which are more common than others. These side effects may be temporary, lasting a few days or weeks. But if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

These are just a few of the more common side effects reported by people who took Plaquenil in clinical studies:

* For more information about this side effect, see “Side effect specifics” below.

Mild side effects can occur with Plaquenil use. This list doesn’t include all possible mild side effects of the drug. For more information, you can refer to Plaquenil’s prescribing information.

Mild side effects that have been reported with Plaquenil include:

These side effects may be temporary, lasting a few days or weeks. But if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks side effects of the medication. If you develop a side effect while taking Plaquenil and want to tell the FDA about it, visit MedWatch.

* For more information about this side effect, see “Side effect specifics” below.

Plaquenil may cause serious side effects. The list below may not include all possible serious side effects of the drug. For more information, you can refer to Plaquenil’s prescribing information.

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

Serious side effects that have been reported and their symptoms include:

  • Ear or hearing problems, including deafness or tinnitus (ringing in your ears). Symptoms can include:
    • balance problems
    • dizziness
    • trouble hearing or loss of hearing
  • Blood disorders, including low levels of white blood cells, red blood cells, or platelets. Symptoms can include:
    • bleeding from your gums or nose
    • feeling tired
    • headache
    • infections
  • Liver problems, including liver failure. Symptoms can include:
    • abdominal (belly) pain
    • jaundice (yellowing of your skin or the whites of your eyes)
  • Hypoglycemia (low blood sugar). Symptoms can include:
    • confusion
    • dizziness
    • sweating
  • Muscle or nerve problems. Symptoms can include:
    • muscle cramps
    • muscle weakness
    • stiff muscles
  • Sleep problems, including nightmares.
  • Suicidal thoughts or behaviors.
  • Ocular (eye) problems.*
  • Skin reactions.*
  • Cardiac (heart) problems.*
  • Allergic reaction.*

* For more information about this side effect, see “Side effect specifics” below.

Plaquenil may cause several side effects. Here are some frequently asked questions about the drug’s side effects and their answers.

Is weight gain a side effect of Plaquenil?

No, weight gain hasn’t been reported as a side effect of Plaquenil. But weight loss has been reported as a side effect.

Two conditions Plaquenil is prescribed to treat, rheumatoid arthritis (RA) and lupus, can cause symptoms that contribute to weight gain. For example, RA can cause joint pain and fatigue (low energy), which can make exercising difficult. And some medications used to treat RA or lupus, such as Trexall (methotrexate), can cause weight gain.

If you have questions or concerns about your weight, talk with your doctor or healthcare professional. They can recommend ways to maintain a weight that’s healthy for you.

Should I expect side effects when stopping Plaquenil?

No, you shouldn’t expect withdrawal symptoms or similar side effects when you stop taking Plaquenil.

But it’s important to note that if you’re taking Plaquenil to treat RA or lupus, your symptoms may get worse if you stop the drug. Because Plaquenil reduces symptoms of these conditions, stopping it could cause symptoms to worsen or come back. But if you’re taking Plaquenil to prevent or treat malaria, you shouldn’t have any side effects after completing treatment.

If you have other questions about withdrawal symptoms and Plaquenil, talk with your pharmacist or doctor.

How long do Plaquenil side effects last? Can any side effects be long-term?

Most of Plaquenil’s side effects are temporary, and last for a few days or weeks. But some side effects could be long-term.

For example, tinnitus (ringing in your ears) or hearing loss caused by Plaquenil may not go away. Plaquenil can also damage your retina (a layer of light-sensitive cells in the back of the eye, which helps you see clearly). Retinal damage can be permanent. The drug can also cause heart failure, which is a chronic (long-term) condition.

Eye problems and heart problems that Plaquenil can cause are discussed in more detail in “Side effect specifics” below.

If you have side effects that last a long time with Plaquenil treatment, be sure to talk with your doctor or pharmacist.

I’m taking a 200-mg dose of Plaquenil. What might be my side effects?

For a list of mild and serious side effects Plaquenil may cause, including those from a 200-mg dose, see the “Mild side effects” and “Serious side effects” sections above. Generally, your risk for side effects tends to increase as your Plaquenil dose increases.

You can find more details on certain Plaquenil side effects in “Side effect specifics” below.

For a complete list of side effects this medication may cause, you can refer to Plaquenil’s prescribing information. You can also speak with your doctor or pharmacist.

Can Plaquenil have effects on my teeth?

No, side effects related to teeth weren’t reported in Plaquenil’s clinical studies.

Two conditions Plaquenil is prescribed to treat, RA and lupus, can cause problems related to teeth and oral health. Recent studies have found connections between both RA and lupus and being at increased risk for problems with dental health. This includes increased risk for periodontal (gum) disease.

If you have questions about managing your dental health, talk with your healthcare professional or dentist.

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

Ocular (eye) problems

Plaquenil can cause ocular (eye-related) problems. This can include damage to your retina (a layer of light-sensitive cells in the back of the eye, which helps you see clearly).

Symptoms of eye problems caused by Plaquenil can include:

You may be at higher risk for damage to your retina if you:

  • take Plaquenil for longer than 5 years
  • take high doses of Plaquenil
  • take certain other drugs, including tamoxifen
  • have certain eye disorders

Retinal damage caused by Plaquenil can be permanent. In some cases, this damage can continue to get worse even after you stop taking the drug.

What you can do

Before you begin taking Plaquenil, tell your doctor about your complete medical history and all medications you take. Your doctor will use this information to determine your risk for retinal damage if you take Plaquenil.

Because of the risk for eye-related side effects, you should have an eye exam within 1 year of starting Plaquenil. Then, depending on your risk for eye problems, your doctor may recommend that you have annual eye exams while taking Plaquenil. If you’re at low risk, you may not need another eye exam unless you take the drug for at least 5 years.

If you experience any eye-related side effects while taking Plaquenil, tell your doctor right away. They’ll have you stop taking the drug, and may recommend other treatments for your condition.

Skin reactions

It’s possible for Plaquenil to cause skin reactions. This can include skin reactions such as:

Although rare, these reactions are very serious and require treatment in a hospital. In extreme cases, they can be life-threatening.

Symptoms of serious skin reactions can include:

  • blisters on your skin, eyes, lips, or mouth
  • burning or itching skin, with or without a fever
  • rash or reddish spots on your body, which may be painful or itchy
  • peeling skin
  • body aches
  • pain and discoloration in the eyes

What you can do

Immediately contact your doctor or get emergency medical help if you develop symptoms of a serious skin reaction while taking Plaquenil. These reactions require treatment in a hospital.

This article contains some pictures of rashes, which are a potential side effect of Plaquenil treatment. It’s important to talk with your doctor about any skin reactions you’re having, so that they can diagnose you.

Cardiac (heart) problems

Taking Plaquenil can cause cardiac (heart-related) problems. These include:

Although rare, some of these problems can be life-threatening.

Symptoms of heart-related problems Plaquenil may cause include:

  • fatigue (low energy)
  • irregular or fast heartbeat
  • swelling in your legs or feet
  • trouble breathing

You may be at higher risk for heart-related problems from Plaquenil if you:

  • have a history of heart disease, including heart attack or heart failure
  • have a history of an abnormal heart rhythm
  • have certain other medical conditions
  • take other medications that can affect your heart rhythm

What you can do

Before you start Plaquenil, tell your doctor about your medical history and all of the medications you take. You shouldn’t take Plaquenil with certain drugs that can affect your heart rhythm. (See this article for details and examples of these drugs.)

Your doctor will determine your risk for heart-related problems with Plaquenil. And they’ll monitor your heart health during treatment. If you might be having heart-related side effects, they’ll probably have you stop taking Plaquenil.

Diarrhea

Taking Plaquenil can cause diarrhea. This side effect was commonly reported in clinical studies.

What you can do

Diarrhea from Plaquenil may go away on its own after a few days.

But if you have diarrhea that won’t go away, is severe, or bothers you, contact your doctor. They may be able to recommend a treatment for this side effect. If it won’t go away, they may recommend switching treatments for your condition.

Allergic reaction

As with most drugs, Plaquenil can cause an allergic reaction in some people.

Symptoms can be mild or serious and can include:

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

What you can do

For mild symptoms of an allergic reaction, call your doctor right away. They may recommend ways to ease your symptoms and determine whether you should keep taking Plaquenil. But if your symptoms are serious and you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Be sure to talk with your doctor about your health history before you take Plaquenil. This drug may not be the right treatment for you if you have certain medical conditions or other factors that affect your health. The conditions and factors to consider include:

Blood disorders, such as anemia (low red blood cell levels). Plaquenil can decrease levels of certain blood cells, including red blood cells. If you have a blood disorder, taking Plaquenil may worsen your condition. Your doctor will help determine whether Plaquenil is safe for you to take.

Gastrointestinal (GI) conditions, such as ulcerative colitis (UC). Plaquenil can cause side effects such as diarrhea, nausea, and vomiting. If you have a GI condition such as UC, you may be at higher risk for these side effects. Plaquenil may also make symptoms of your condition worse. Your doctor may monitor your GI condition more closely if they decide Plaquenil is safe for you to take.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency. G6PD is a protein that keeps your red blood cells healthy. Taking Plaquenil could cause red blood cells to burst in people who have G6PD deficiency (a lack of G6PD). Your doctor will help determine whether Plaquenil is safe for you to take.

History of suicidal thoughts or behaviors. Although rare, Plaquenil can cause suicidal thoughts or behaviors. You may be at higher risk if you’ve experienced this previously. Your doctor will help determine whether Plaquenil is safe for you to take. Make sure to call 911 or your local emergency number if you experience any suicidal thoughts or actions while taking Plaquenil.

Kidney disease, such as chronic kidney disease. If you have kidney disease, your body may not be able to properly get rid of Plaquenil. This could cause a buildup of toxic blood levels of the drug. Your doctor will help determine whether Plaquenil is safe for you to take. They may recommend a lower dose of the medication. Or they may recommend trying another treatment for your condition.

Liver disease, including hepatitis. Taking Plaquenil can cause liver damage. People who have liver disease may be at higher risk for this side effect, which could make your existing condition worse. Your doctor will help determine whether Plaquenil is safe for you to take. They may recommend having blood tests more often than usual during treatment to monitor your liver health. Or, they may recommend trying a different treatment.

Psoriasis. If you have psoriasis, Plaquenil could worsen your condition. Your doctor will help determine whether Plaquenil is safe for you to take.

Allergic reaction. You shouldn’t take Plaquenil if you’ve ever had an allergic reaction to Plaquenil or any of its ingredients. Talk with your doctor about which other treatments are better choices for you.

Alcohol use with Plaquenil

Alcohol isn’t known to interact with Plaquenil. But both Plaquenil and alcohol can cause liver damage. Combining the two substances may increase your risk for liver damage.

If you drink alcohol, talk with your doctor about how much, if any, alcohol is safe for you to have while taking Plaquenil.

Pregnancy and breastfeeding while taking Plaquenil

It isn’t known if Plaquenil is safe to take during pregnancy. If you’re pregnant or planning to become pregnant, talk with your doctor before taking Plaquenil. They can recommend whether it’s safe for you to take this drug.

If you do take Plaquenil during pregnancy, you might consider signing up for the Plaquenil pregnancy registry by calling 877-311-8972. Your doctor can provide more information about this.

Talk with your doctor about using Plaquenil while breastfeeding and whether this is considered safe. Plaquenil does pass into breast milk. But side effects haven’t been reported in breastfed children. Talk with your doctor about feeding options, including breastfeeding, for your child if you’re taking Plaquenil.

Plaquenil can cause mild or serious side effects. Your doctor or pharmacist can help answer any questions you have about side effects you experience during your treatment.

Besides talking with your doctor, you can do some research on your own. These articles might help:

  • More information on Plaquenil. For details on other aspects of Plaquenil, refer to this article.
  • Drug comparison. To learn how Plaquenil compares with chloroquine, read this article. For information about how Plaquenil compares with Humira, see this article.
  • A look at your condition. For details on the conditions Plaquenil is approved to treat, these lists of lupus articles and rheumatology articles may be helpful.

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 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.