Plaquenil (hydroxychloroquine) is a prescription drug that treats and prevents malaria. It also treats rheumatoid arthritis and lupus. This drug can interact with alcohol and other medications, including semaglutide (Ozempic) and certain antidepressants.
Plaquenil is used in adults and certain children to prevent and treat malaria. It’s also used in adults to treat:
An interaction can occur because one substance causes another substance to have a different effect than expected. Interactions can also occur if you have certain health conditions.
Keep reading to learn about Plaquenil’s possible interactions. And for more information about Plaquenil, including details about its uses, see this article.
Certain health conditions or other factors could raise your risk of harm if you take Plaquenil. In such cases, your doctor may not prescribe Plaquenil for you. These are known as contraindications. Plaquenil’s contraindications are described below.
If you’ve had an allergic reaction. If you’ve had an allergic reaction to Plaquenil or any of its ingredients, your doctor likely will not prescribe Plaquenil. They also won’t prescribe Plaquenil if you’ve had an allergic reaction to medications in the same group of drugs as Plaquenil. This is because taking the drug could cause another allergic reaction. You can ask your doctor about other treatments that may be better options for you.
There’s no known interaction between Plaquenil and alcohol. But alcohol and Plaquenil may cause similar side effects. So drinking alcohol with Plaquenil can worsen or increase your risk of these side effects, such as:
If you drink alcohol, talk with your doctor about how much (if any) may be safe to consume during your Plaquenil treatment.
Before you start taking Plaquenil, tell your doctor and pharmacist about any prescription, over-the-counter, or other drugs you take. Sharing this information with them may help prevent possible interactions. (To learn whether Plaquenil interacts with supplements, herbs, and vitamins, see the “Are there other interactions with Plaquenil?” section below.)
If you have questions about drug interactions that may affect you, talk with your doctor or pharmacist.
The table below lists drugs that may interact with Plaquenil. Keep in mind that this table doesn’t include all drugs that may interact with Plaquenil. For more information about some of these interactions, see the “Drug interactions explained” section below.
|Drug group or drug name||Drug examples||What can happen|
|drugs that can cause long QT syndrome (abnormal electrical activity of the heart)||• certain antipsychotics, such as quetiapine (Seroquel)|
• certain antidepressants, such as amitriptyline
• certain antibiotics, such as levofloxacin (Levaquin)
|can increase the risk of irregular heart rhythm|
|drugs that affect your heart rhythm||• amiodarone (Pacerone)|
|can raise the risk of irregular heart rhythm|
|diabetes drugs||• semaglutide (Ozempic)|
• insulin glargine (Lantus)
• sitagliptin (Januvia)
• metformin (Fortamet)
|can enhance the effect of diabetes drugs, which increases your risk of low blood sugar|
|mefloquine||—||can raise the risk of seizures and increase the risk of long QT syndrome|
|seizure drugs||• gabapentin (Neurontin, Gralise) • lamotrigine (Lamictal) • topiramate (Topamax)||can make seizure drugs less effective|
|methotrexate (Otrexup, Trexall)||—||can raise the risk of side effects from methotrexate|
|cyclosporin Sandimmune, Neoral, others)||—||can raise the risk of side effects from cyclosporin|
|digoxin (Lanoxin)||—||can increase the risk of side effects from digoxin|
|cimetidine (Tagamet)||—||can raise the risk for side effects from Plaquenil|
|rifampicin (Rifadin)||—||can make Plaquenil less effective|
|praziquantel (Biltricide)||—||can make praziquantel less effective|
|antacids||—||can make Plaquenil less effective|
|ampicillin (Polyflex, Unasyn)||can make ampicillin less effective|
Learn more about certain drug interactions that can occur with Plaquenil.
Interaction with diabetes drugs
If you have diabetes, you might take medications to help lower your blood sugar. Certain medications can interact with Plaquenil. They may include drugs that you swallow or that you inject under your skin.
Examples of diabetes drugs include:
- semaglutide (Ozempic)
- insulin glargine (Lantus, Basaglar)
- sitagliptin (Januvia)
- metformin (Fortamet)
- glipizide (Glucotrol XL)
What could happen
Diabetes drugs help lower your blood sugar. Plaquenil can also decrease your blood sugar level. So taking these drugs together can increase your risk of hypoglycemia (low blood sugar).
Symptoms of hypoglycemia can include:
What you can do
If you take Plaquenil with diabetes drugs, your doctor will likely have you check your blood sugar levels more often. If needed, they may lower the dosage of your diabetes medication to reduce your risk of hypoglycemia.
If you have symptoms of hypoglycemia while taking Plaquenil, tell your doctor. They can give you tips to quickly raise your blood sugar.
Interaction with seizure drugs
Plaquenil can interact with medications used to treat or prevent seizures.
Examples of seizure medications include:
- gabapentin (Neurontin, Gralise)
- lamotrigine (Lamictal)
- topiramate (Topamax)
- carbamazepine (Tegretol, Equetro, others)
What could happen
Plaquenil can raise your risk of seizures. Because of this, taking Plaquenil may make your seizure medication less effective.
What you can do
Before starting Plaquenil treatment, let your doctor know if you take seizure medications. They may recommend a different treatment option other than Plaquenil.
Plaquenil may have other interactions. They could occur with supplements, foods, vaccines, or even lab tests. See below for details. Note that the information below doesn’t include all other possible interactions with Plaquenil.
Does Plaquenil interact with supplements?
Before you start taking Plaquenil, talk with your doctor and pharmacist about any supplements, herbs, and vitamins you take. Sharing this information with them may help you avoid possible interactions.
If you have questions about interactions that may affect you, talk with your doctor or pharmacist.
Plaquenil and herbs
There are currently no reports of Plaquenil interacting with herbs. But this doesn’t mean that interactions with herbs won’t be recognized in the future.
For this reason, it’s still important to check with your doctor or pharmacist before taking any of these products during treatment with Plaquenil.
Plaquenil interactions with vitamins
There are currently no reports of Plaquenil interacting with vitamins. But this doesn’t mean that vitamin interactions won’t be recognized in the future.
For this reason, it’s still important to check with your doctor or pharmacist before taking any of these products during your Plaquenil treatment.
Does Plaquenil interact with food?
There are currently no reports of Plaquenil interacting with food. If you have questions about eating certain foods during your treatment with Plaquenil, talk with your doctor.
Does Plaquenil interact with vaccines?
No vaccines have been reported to interact with Plaquenil. Talk with your doctor if you have concerns about getting vaccines during your Plaquenil treatment.
Does Plaquenil interact with lab tests?
Currently, there aren’t any lab tests known to interact with Plaquenil. But this doesn’t mean that lab test interactions won’t be recognized in the future. Because of this, it’s important to talk with your doctor if you need any lab tests during your Plaquenil treatment.
Does Plaquenil interact with cannabis or CBD?
There are currently no reports of Plaquenil interacting with cannabis (commonly called marijuana) or cannabis products such as cannabidiol (CBD). But, as with any drug or supplement, talk with your doctor before using cannabis during your treatment with Plaquenil.
Note: Cannabis is illegal at a federal level but is legal in many states to varying degrees.
Certain medical conditions or other health factors may raise the risk of interactions with Plaquenil. Before taking Plaquenil, talk with your doctor about your health history. They’ll determine whether Plaquenil is right for you.
Health conditions or other factors that might interact with Plaquenil include:
Heart problems. Plaquenil can cause heart problems, such as cardiomyopathy and irregular heart rhythm. If you already have these conditions, taking Plaquenil could make them worse. Before taking Plaquenil, tell your doctor if you have any heart problems. They’ll determine whether this medication is a safe option for you.
Eye conditions, such as macular degeneration. In rare cases, Plaquenil can cause serious eye problems. The risk is higher if you already have an eye condition called macular degeneration. Before taking Plaquenil, tell your doctor if you have any eye problems. They’ll likely check your vision before you start Plaquenil treatment and regularly during your treatment. If you develop serious vision problems, they’ll likely have you stop taking Plaquenil and switch to a different treatment.
Porphyria. If you have a rare blood condition called porphyria, taking Plaquenil can worsen it. Before you start taking Plaquenil, let your doctor know if you have this condition. They can determine whether this medication is right for you.
Psoriasis. If you have psoriasis, Plaquenil may cause a flare-up of your symptoms. Let your doctor know if you have this condition before starting Plaquenil treatment. They can determine whether Plaquenil is right for you.
Low levels of blood cells. Plaquenil can cause low levels of blood cells, including red blood cells, white blood cells, and platelets. Your doctor will likely check your blood cell levels before you start Plaquenil treatment.
If your levels are already low, they may recommend a different treatment option for you. If you take Plaquenil long term, your doctor will likely check your blood cell levels regularly during your treatment. If your cell levels become too low, they’ll have you stop taking Plaquenil.
Glucose-6-phosphate dehydrogenase (G6PD) deficiency. G6PD is a protein that helps your red blood cells function properly. Taking Plaquenil if you have a G6PD deficiency can destroy your red blood cells, which may lead to anemia (low levels of red blood cells).
Before starting Plaquenil treatment, talk with your doctor if you have a G6PD deficiency. They can determine whether this medication is safe for you.
Problems with muscle strength. Taking Plaquenil can cause nerve problems that may lead to muscle weakness and problems with movement. If you already have a condition that affects your muscle strength or movement, Plaquenil may make it worse. Talk with your doctor about your health history before you start taking Plaquenil. They’ll let you know if this medication is right for you.
Kidney or liver problems. Having kidney or liver problems may cause Plaquenil to build up in your body, which can increase your risk of side effects. Before starting Plaquenil treatment, talk with your doctor if you have kidney or liver problems. They may prescribe a lower dosage to reduce your risk of side effects.
Seizures. Plaquenil can increase your risk of seizures. This risk may be higher if you’ve had seizures before. Before you start taking Plaquenil, tell your doctor if you’ve had seizures in the past. They may recommend a different treatment option for you.
Low potassium or magnesium levels. Taking Plaquenil can cause certain heart problems, including an irregular heart rhythm. This risk may be higher if you have low potassium or magnesium levels that aren’t being treated.
Before taking Plaquenil, tell your doctor if you have low levels of potassium or magnesium. If you’re not sure, ask your doctor if they can check your levels. If your levels are low, your doctor will likely have you take supplements to increase them before you start Plaquenil treatment.
Pregnancy. It’s not known whether it’s safe to take Plaquenil during pregnancy. But small studies of people taking Plaquenil during pregnancy have not shown that the drug causes harm to a fetus or a pregnant person.
- anemia (low levels of red blood cells) in the pregnant person
- premature birth
- low birth weight
- pregnancy loss
If you’re pregnant or planning to become pregnant, talk with your doctor before taking Plaquenil. They can provide more details about the risks and benefits of taking Plaquenil during pregnancy.
If you take Plaquenil while pregnant, your doctor may recommend that you enroll in a pregnancy registry. Pregnancy registries help healthcare professionals learn about the safety of taking certain drugs, such as Plaquenil, during pregnancy. For more information, call 877-311-8972 or talk with your doctor.
Breastfeeding. It’s not known if Plaquenil is safe to take while breastfeeding. A small amount of Plaquenil can pass into breast milk, but there have been no reports of Plaquenil causing harm to a breastfed child.
If you’re breastfeeding or planning to do so, talk with your doctor before taking Plaquenil.
Allergic reaction. If you’ve had an allergic reaction to Plaquenil or any of its ingredients, your doctor will likely not prescribe Plaquenil. They also won’t prescribe this medication if you’ve had an allergic reaction to certain drugs called 4-aminoquinolones. This is because taking the drug could cause another allergic reaction. You can ask your doctor about other treatments that may be better choices for you.
Mental health conditions. In rare cases, Plaquenil may cause certain mental health conditions, including suicidal thoughts or behaviors. Before you start taking Plaquenil, talk with your doctor about any mental health condition you have. They can help determine whether this drug is right for you.
Help is out there
If you or someone you know is in crisis and considering suicide or self-harm, please seek support:
- Call the 988 Suicide and Crisis Lifeline at 988.
- Text HOME to the Crisis Textline at 741741.
- 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 are not in the same household, stay on the phone with them until help arrives.
Find answers to some frequently asked questions about Plaquenil and possible interactions.
Can I take Plaquenil at night to avoid interactions with my morning medications?
The best time of day to take Plaquenil may depend on several factors, including your Plaquenil dosage and the condition you’re taking Plaquenil to treat.
Plaquenil can interact with some medications, including medications you take in the morning. Spacing out when you take Plaquenil and other drugs doesn’t usually reduce the risk of interactions. But for medications such as antacids, you’ll need to time your doses correctly.
Before starting Plaquenil treatment, it’s important to tell your doctor about all the medications you take. They can determine whether taking Plaquenil with your other medications is safe. In some cases, your doctor may lower the dosage of your other drugs (such as diabetes medications) to reduce your risk of side effects.
If you have more questions about how Plaquenil may affect your other medications, talk with your doctor or pharmacist.
How do Plaquenil’s interactions compare with those of Humira?
Plaquenil and Humira are both used to treat rheumatoid arthritis, but they work in different ways to treat the condition. These drugs have some similar interactions and others that vary.
For example, both Plaquenil and Humira can interact with the organ transplant rejection drug cyclosporine (Gengraf, Neoral). And Plaquenil and Humira have a few of the same health-related interactions. These include certain risks in people with liver problems or heart problems.
Plaquenil and Humira have different interactions as well. To learn more about how these drugs compare, talk with your doctor. And for more information about Humira’s interactions, see this article.
Taking certain steps can help you avoid interactions with Plaquenil. Before starting treatment, talk with your doctor and pharmacist. Things to discuss with them include:
- Whether you drink alcohol or use cannabis.
- Other medications you take, as well as any vitamins, supplements, and herbs. Your doctor or pharmacist can help you fill out a
- What to do if you start taking a new drug during your Plaquenil treatment.
It’s also important to understand Plaquenil’s
If you have trouble reading or understanding this information, your doctor or pharmacist can help.
Taking Plaquenil exactly as prescribed can also help prevent interactions.
If you still have questions about Plaquenil and its possible interactions, talk with your doctor.
Questions you may want to ask your doctor include:
- Are there Plaquenil contraindications that may affect other drugs I take?
- Does my risk of interactions depend on the dosage I take?
- If I take Plaquenil and have heart disease, will I be monitored more closely during treatment?
- Could I still take Plaquenil even if it interacts with a health condition I have?
To learn more about Plaquenil, see these articles:
To get information on different conditions and tips for improving your health, subscribe to any of Healthline’s newsletters. You may also want to check out the online communities at Bezzy. It’s a place where people with certain conditions can find support and connect with others.
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.