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 or hydroxychloroquine, unless your doctor recommends that you do so.
For more information on COVID-19, including prevention, treatment, and the latest developments, visit our COVID-19 hub.
Plaquenil (hydroxychloroquine) is a brand-name drug prescribed for the following uses:
- treating and helping prevent malaria
- treating rheumatoid arthritis
- treating systemic lupus erythematosus
- treating chronic discoid lupus erythematosus
As with other medications, Plaquenil can interact with certain other drugs. An interaction occurs when one substance causes another substance to have a different effect than expected.
For details about Plaquenil’s interactions, keep reading. For additional information about Plaquenil, including details about its uses, see this article.
In some cases, factors or conditions could prevent your doctor from prescribing Plaquenil due to the risk of harm. These are known as contraindications. The contraindications of Plaquenil include:
Having had an allergic reaction to Plaquenil, any of its ingredients, or similar drugs
If you have had an allergic reaction to Plaquenil or any of its ingredients, your doctor will likely not prescribe Plaquenil. They also won’t usually prescribe Plaquenil if you’ve had an allergic reaction to similar drugs known as 4-aminoquinolines. An example of these drugs is chloroquine.
Taking Plaquenil in these situations could cause another allergic reaction. You can ask your doctor about other treatments that may be better choices for you.
Note: Before you start treatment with Plaquenil, it’s important to tell your doctor whether this contraindication applies to you. They can then determine whether to prescribe Plaquenil.
Plaquenil isn’t known to interact with alcohol. However, certain side effects from Plaquenil could be worsened by drinking alcohol. Examples of these side effects include headache, nausea, and dizziness. (For information about Plaquenil’s side effects, see this article.)
In addition, drinking large amounts of alcohol can damage your liver. Plaquenil may also cause liver problems, such as liver failure. So drinking alcohol with Plaquenil could increase your risk of liver problems.
If you drink alcohol, talk with your doctor about how much, if any, is safe to consume while you’re taking Plaquenil.
Before you start treatment with Plaquenil, tell your doctor and pharmacist which prescription, over-the-counter, and other medications you take. By sharing this information with them, you may help prevent possible interactions. (To learn whether Plaquenil interacts with supplements, herbs, or vitamins, see “Plaquenil and other interactions” below.)
If you have questions about drug interactions that may affect you, ask your doctor or pharmacist.
Here’s a table of drugs that can interact with Plaquenil. Keep in mind that this table doesn’t include all drugs that may interact with Plaquenil. Some of these interactions are described in detail just below in “Drug interactions in depth.”
|Drug type or drug name||Drug examples||Interaction result with Plaquenil|
|diabetes medications||• insulin lispro (Humalog)|
• insulin glargine (Lantus)
• glipizide (Glucotrol XL)
|can increase the effect of diabetes medications|
|seizure medications||• carbamazepine (Carbatrol, Tegretol, others)|
• lamotrigine (Lamictal)
• topiramate (Topamax)
|can make seizure medications less effective than usual|
|antacids||• calcium carbonate (Tums, Alka-Seltzer)|
• calcium hydroxide/magnesium hydroxide (Rolaids)
• aluminum hydroxide/magnesium hydroxide/simethicone (Maalox, Mylanta)
|can make Plaquenil less effective than usual|
|drugs that can affect your heart rhythm||• amiodarone (Pacerone)|
• sotalol (Betapace, Sorine)
• haloperidol (Haldol)
• quetiapine (Seroquel)
|can increase the risk of heart-related side effects from Plaquenil and drugs that can affect your heart rhythm*|
|bupropion (Wellbutrin, Aplenzin, others)||—||can increase the risk of seizures from Plaquenil and bupropion|
|mefloquine||—||can increase the risk of seizures from Plaquenil and mefloquine|
|cimetidine (Tagamet)||—||can increase the risk of side effects from Plaquenil*|
|methotrexate (Trexall, Otrexup, others)||—||can increase the risk of side effects from Plaquenil* and methotrexate|
|cyclosporine (Neoral, Sandimmune, others)||—||can increase the risk of side effects from cyclosporine|
|digoxin (Lanoxin)||—||can increase the effect and risk of side effects from digoxin|
|rifampin (Rifadin, Rimactane)||—||can make Plaquenil less effective than usual|
* For information about Plaquenil’s side effects, see this article.
Here’s a closer look at certain drug interactions of Plaquenil.
Drugs that can affect your heart rhythm
Several drugs can cause heart-related side effects, and some can affect your heart rhythm. Specifically, certain drugs, including Plaquenil, can lengthen part of your heart rhythm called the QT interval. This is called long QT syndrome. It can be seen with a test called an EKG. An EKG tracks the electrical activity in your heart.
Interaction result. Taking Plaquenil with other drugs that can cause long QT syndrome can increase your risk of this side effect. Long QT syndrome can cause serious and sometimes life threatening irregular heartbeats.
Interaction explained. Taking Plaquenil with another drug that can lengthen the QT interval can further lengthen your QT interval. This change in the electrical activity in your heart can make it harder for your heart to beat correctly. As a result, you may have an increased risk of irregular heartbeats.
Examples of drugs that can affect your heart rhythm. Here are some drugs that may increase the risk of abnormal heart rhythms with Plaquenil:
- certain drugs used to treat irregular heart rhythms, such as amiodarone (Pacerone), flecainide, and sotalol (Betapace, Sorine)
- certain antimalarials, such as artemether/lumefantrine (Coartem), mefloquine, and chloroquine
- certain antibiotics, such as clarithromycin, azithromycin (Zithromax), and ciprofloxacin (Cipro)
- certain antipsychotics, such as aripiprazole (Abilify), chlorpromazine, and haloperidol (Haldol)
- certain antidepressants, such as citalopram (Celexa) and mirtazapine (Remeron)
Steps you or your doctor may take. Before starting Plaquenil treatment, be sure to tell your doctor about any other medications you take.Due to the serious risk associated with this interaction, your doctor will likely not prescribe Plaquenil with other drugs that can lengthen the QT interval. You can talk with your doctor about other treatment options for your condition.
Diabetes medications are used to help manage your blood sugar levels.
Interaction result. Taking Plaquenil with diabetes medications can increase the effect of diabetes drugs. This can make hypoglycemia (low blood sugar) more likely to occur.
Interaction explained. Diabetes medications work by lowering your blood sugar levels. Plaquenil can lower your blood sugar levels and sometimes cause hypoglycemia, which may be severe.
Taking a diabetes drug during Plaquenil treatment may lower your blood sugar further. This can increase your risk of hypoglycemia.
Symptoms of hypoglycemia can include irritability, hunger, dizziness, and confusion. Other symptoms can include blurry vision, trouble with coordination, fast heartbeat, and tremor.
Examples of diabetes medications. Here are some diabetes medications that may interact with Plaquenil:
- insulin lispro (Humalog)
- insulin glargine (Lantus)
- glipizide (Glucotrol XL)
Steps you or your doctor may take. If you take Plaquenil with a diabetes medication, your doctor may recommend checking your blood sugar more frequently. They may also lower your dosage of diabetes medication to reduce your risk of hypoglycemia.
Be sure to ask your doctor what to do if you have symptoms of hypoglycemia while taking Plaquenil.
Antacids are drugs used to relieve indigestion and heartburn.
Interaction result. Taking an antacid with Plaquenil could make Plaquenil less effective than usual.
Interaction explained. Antacids neutralize the acid in your stomach. This can affect the way your body absorbs other drugs from your digestive system. Taking an antacid with Plaquenil may reduce the level of Plaquenil that’s absorbed into your bloodstream. This means you may not get the full dose of Plaquenil, which could make it less effective than usual.
Examples of antacid drugs. Here are some antacids that may interact with Plaquenil:
- calcium carbonate (Tums, Alka-Seltzer)
- calcium hydroxide/magnesium hydroxide (Rolaids)
- aluminum hydroxide/magnesium hydroxide/simethicone (Maalox, Mylanta)
Steps you or your doctor may take. You should avoid taking antacids in the 4 hours before and 4 hours after taking Plaquenil. If you have indigestion or heartburn during this time, talk with your doctor or pharmacist. They can recommend other ways to relieve your symptoms.
Plaquenil may have other interactions, such as with supplements, foods, vaccines, or even lab tests. You’ll find details below. Keep in mind that the following information does not include all other possible interactions with Plaquenil.
Plaquenil and supplements
It’s possible for drugs to interact with supplements such as vitamins and herbs.
Plaquenil and herbs
There have been no specific reports of herbs interacting with Plaquenil. However, that doesn’t mean herbal interactions won’t occur or be recognized in the future. Because of this, it’s important to check with your doctor or pharmacist before taking any of these products during Plaquenil treatment.
Plaquenil and vitamins
No vitamins have been reported to interact with Plaquenil. Keep in mind that doesn’t mean vitamin interactions won’t occur or be recognized in the future. Due to this, you should talk with your doctor or pharmacist before taking any vitamin product with Plaquenil.
Plaquenil and food
There were no reports of food interactions with Plaquenil.
In fact, it’s important that you take Plaquenil with food or a glass of milk. You should not take the medication on an empty stomach. Taking Plaquenil on an empty stomach can increase your risk of digestive side effects from the drug, including indigestion.
Also, you should not take medication for indigestion at least 4 hours before or after taking Plaquenil.* The best way to help prevent indigestion is by taking your dose with food or a glass of milk.
If you’d like to learn more about eating certain foods during treatment with Plaquenil, talk with your doctor.
* For more information, see “Antacids” in “Drug interactions in depth” above.
Plaquenil and vaccines
There have been no specific reports of vaccines interacting with Plaquenil. However, that doesn’t mean vaccine interactions won’t occur or be recognized in the future. To be safe, talk with your doctor or pharmacist before getting any vaccines while taking Plaquenil.
Plaquenil and lab tests
There haven’t been any specific reports of Plaquenil interacting with lab tests. Keep in mind that doesn’t mean lab test interactions won’t occur or be recognized in the future. Because of this, you should talk with your doctor or pharmacist if you need any lab tests during Plaquenil treatment.
PLAQUENIL AND CANNABIS OR CBD
Cannabis (often called marijuana) and cannabis products, such as cannabidiol (CBD), have not been specifically reported to interact with Plaquenil. However, as with any drug or supplement, talk with your doctor before using cannabis in combination with Plaquenil. The impact of cannabis may affect how well you stick to your Plaquenil treatment plan.
Note: Cannabis is illegal at a federal level but is legal in many states to varying degrees.
Certain medical conditions and other factors may increase the risk of interactions with Plaquenil. Before you take this drug, be sure to talk with your doctor about your health history. Plaquenil may not be the right treatment option if you have certain medical conditions or other factors affecting your health.
Health conditions or factors that might interact with Plaquenil include the following:
Allergic reaction. If you’ve had an allergic reaction to Plaquenil, any of its ingredients, or similar drugs such as chloroquine, your doctor will likely not prescribe Plaquenil. To learn more, see “When to avoid Plaquenil” above.
Heart conditions. Plaquenil may affect your heart. You may have an increased risk of heart-related side effects if you:
- have heart disease such as heart failure
- have had a heart attack
- have a heart condition such as a slow or irregular heartbeat, or an irregular heart rhythm called long QT syndrome
You can talk with your doctor about whether Plaquenil is safe for you.
Kidney or liver problems. Plaquenil can sometimes cause liver and kidney problems. If you already have a liver or kidney problem, the drug could worsen your condition.
Plaquenil could also build up in your body if you have a liver or kidney problem. These organs are responsible for clearing the medication from your body. If they aren’t working correctly, the level of Plaquenil in your system could rise, which could increase your risk of side effects.
Due to these risks, your doctor may prescribe a Plaquenil dosage that’s lower than usual. They may also monitor you more closely for possible side effects.
Psoriasis. If you have psoriasis, Plaquenil could worsen it. Due to this risk, your doctor may not prescribe the medication. They can advise you on other treatment options that may be better for you.
Porphyria. If you have a rare genetic condition called porphyria, Plaquenil could worsen it. Due to this risk, your doctor may not prescribe the drug. You can ask them about other treatments.
Low blood cell counts. Plaquenil can lower levels of red blood cells, white blood cells, and platelets. If you already have a low blood cell count, such as anemia, Plaquenil could worsen it. Your doctor will likely monitor your blood cell levels more often while you take Plaquenil. Or they may recommend a different medication for your condition.
G6PD deficiency. Glucose-6-phosphate dehydrogenase (G6PD) is a protein that keeps your red blood cells healthy. If you have a G6PD deficiency, you don’t have enough G6PD in your blood. In this case, taking Plaquenil may destroy red blood cells. This can lead to anemia.
If you have a G6PD deficiency, your doctor may monitor your blood cells more often while you take Plaquenil. Or they may recommend a medication other than Plaquenil for your condition.
Neurological conditions. Plaquenil can sometimes cause seizures or other problems affecting your nervous system and muscles, such as movement problems. If you have epilepsy or another neurological condition, Plaquenil could worsen your symptoms. Be sure to talk with your doctor about whether the drug is right for you.
Pregnancy. It’s not known whether Plaquenil is safe to take during pregnancy. If you’re pregnant or planning to become pregnant, talk with your doctor about the possible risks and benefits of taking Plaquenil.
Breastfeeding. Plaquenil can pass into breast milk in small amounts. There haven’t been reports of side effects in children exposed to Plaquenil in breast milk. However, it’s not known whether the medication is safe to take while breastfeeding. If you’re breastfeeding or planning to breastfeed, talk with your doctor about the best way to feed your child while taking Plaquenil.
Mental health conditions. On rare occasions, Plaquenil may cause suicidal thoughts or behaviors. If you have a mental health condition, such as depression, you may have an increased risk of this side effect. You can talk with your doctor about whether Plaquenil is the right treatment option.
Note: For information about Plaquenil’s side effects, see this article.
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 988 Suicide and Crisis Lifeline is available 24 hours a day at 988. During a crisis, people who are hard of hearing can use their preferred relay service or dial 711 then 988.
Here are some frequently asked questions about Plaquenil and possible interactions.
Is there an interaction between melatonin and Plaquenil?
No. There are no specific reports of Plaquenil interacting with melatonin (a supplement often taken as a sleep aid).
However, both Plaquenil and melatonin can sometimes cause nausea, dizziness, or headaches.* So you may have an increased risk of these side effects if you take melatonin during Plaquenil treatment. If you’re interested in taking melatonin, you should check with your doctor first.
* For information about Plaquenil’s side effects, see this article.
Can I take acetaminophen if I’m taking Plaquenil?
In general, yes, it’s safe to take acetaminophen with Plaquenil. There aren’t reports of these medications interacting with each other.
However, keep in mind that both acetaminophen and Plaquenil can cause liver problems, including liver damage. This side effect isn’t likely with acetaminophen unless you take higher doses than recommended. Your risk is also increased if you consume alcohol and take these medications together.
Before taking acetaminophen or any over-the-counter medication, talk with your doctor or pharmacist. They can advise you on whether the medication is safe for you and what the right dosage is.
You can take certain steps to help prevent interactions with Plaquenil. Your doctor and pharmacist are key resources, so reach out to them before starting treatment. For example, you should plan to do the following:
- Let them know if you drink alcohol or use cannabis.
- Tell them about any other medications you take, as well as any supplements, herbs, and vitamins.
- Create a
medication list, which your doctor and pharmacist can help you fill out.
It’s also important to read the Plaquenil label and other
If you need help reading or understanding this information, ask your doctor or pharmacist.
You can also help prevent interactions with Plaquenil by taking it exactly as your doctor prescribes.
Besides learning about interactions, you may want to find out more about Plaquenil. These resources might help:
- Overview of Plaquenil. For a general overview of Plaquenil, you can read this article.
- Side effects. If you’re interested in the side effects of Plaquenil, see this article. Another option is to refer to the Plaquenil prescribing information.
- Dosage specifics. To learn about the dosage of Plaquenil, see this article.
- Facts about your condition. To learn more about rheumatoid arthritis, visit our rheumatoid arthritis hub. For information about lupus, refer to this list of lupus articles.
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.