Plaquenil (hydroxychloroquine)

Plaquenil is not recommended:

• For treatment against certain malaria strains, such as those with chloroquine or hydroxychloroquine-resistant strains.
• For treatment of severe malaria conditions.
• For treatment of COVID-19 unless used as part of a clinical study.

Plaquenil may sometimes be prescribed for other uses, such as porphyria cutanea tarda.

How is Plaquenil used?

Plaquenil can be taken alone or with other medications. Plaquenil is available in tablet form.

Storage

Store Plaquenil in a tightly closed container away from direct light, heat, or moisture at room temperature.

Keep out of reach of children.

Instruction

Take Plaquenil by mouth with food or milk as directed by your doctor. Ask your doctor or pharmacist for further direction if you do not understand the instruction.

Take Plaquenil as a whole tablet – do not break, chew, or crush the tablet.

Take Plaquenil for the entire prescribed duration even if you start to feel better.

Dosage

Prevention of malaria

Plaquenil must be started 1-2 weeks before traveling to the affected area. Take the prescribed dose* once a week on the same day every week. Continue taking Plaquenil weekly during your travel and for the following four weeks after leaving the affected area.

Treatment of malaria

Treatment will start with one high dose* taken immediately followed by smaller doses at the 6-hour, 24-hour, and 48-hour mark.

*Pediatric patients will be prescribed doses based on their weight.

Treatment of auto-immune diseases

Take the dose as prescribed by your doctor once or twice daily. Your doctor will adjust your dose as needed.

Side Effects

It’s important to understand that although Plaquenil is FDA approved, it comes with side effects that may or may not affect you.

Before starting Plaquenil, you should discuss possible side effects with your doctor or pharmacist.

Common Side Effects

Not all side effects require medical attention. As your body adjusts to Plaquenil, side effects may go away.

Tell your doctor if you experience the following symptoms, and they become severe or do not go away on their own:

• Rash, itching
• Vomiting, nausea
• Weight loss
• Dizziness, headaches
• Loss of appetite
• Abdominal pain
• Hair loss or thinning
• Diarrhea
• Severe sunburn
• Irritability

Serious Side Effects

Severe adverse reactions while taking Plaquenil are not common but can occur. Seek emergency medical care or call 911 if you experience any of the following symptoms:

• Allergic reaction: difficulty breathing, hives, swelling in your throat or face
• Severe skin reaction: sore throat, fever, painful skin, burning eyes, blistering rash, and peeling
• Heart problem: shortness of breath, fluttering in your chest, sudden dizziness, and fast or pounding heartbeats

Call your doctor urgently if you experience any of the following symptoms:

• Seizures
• Sensitivity to light
• Seeing flashing lights or halos around lights
• Changes to vision; blurry, hazy, cloudy, distorted
• Changes to eye color
• Trouble focusing or reading
• Severe muscle weakness
• Ringing in ears or trouble hearing
• Drowsiness
• Decrease or loss of consciousness
• Convulsions
• Irregular heartbeat
• Irregular or unusual bleeding and bruising
• Anxiety, depression, or suicidal thoughts

The information above does not list all possible side effects. Contact your doctor or pharmacist if you experience any side effects not listed. You or your doctor may report side effects to the FDA by calling 1-800-FDA-1088.

Warnings & Precautions

Before taking Plaquenil, tell your doctor or pharmacist:

• If you are allergic to any medications. You should not use Plaquenil if you are allergic to chloroquine, hydroxychloroquine, quinine, or primaquine.
• If you excessively use alcohol. Using alcohol while on Plaquenil may increase your risk for liver problems.
• If you plan to become pregnant, are pregnant, or are breastfeeding.
• If you have psoriasis. Plaquenil may trigger a severe case of psoriasis.
• If you have porphyria. Plaquenil may worsen porphyria.
• Your medical history, especially if you have had diabetes, heart problems, kidney problems, or vision problems.

Overdose

Plaquenil can be quickly absorbed into the body. In cases of accidental overdose, symptoms can appear within 30 minutes. If overdose is suspected, seek immediate medical attention. An overdose will be treated based on symptoms.

Overdosed symptoms include drowsiness, visual changes, headaches, cardiovascular failure, cardiac arrest, torsades de pointes, convulsions, QT prolongation, hypokalemia, ventricular tachycardia, and ventricular fibrillation.

Breastfeeding

Plaquenil can pass into breast milk. Since there are no consistent studies, Plaquenil may or may not pose a risk to your child. Consult with your doctor to determine whether you should take Plaquenil while breastfeeding.

Hypoglycemia

Plaquenil may lower your blood sugar resulting in hypoglycemia which can be life-threatening. Low blood sugar must be treated immediately upon onset. If you have diabetes, you will need to monitor and measure your glucose level as directed by your doctor.

Consult with your doctor to understand the signs and symptoms of low blood sugar, such as hunger, sweating, headache, irritability, dizziness and feeling shaky or anxious, or an increased heart rate.

If you develop any signs or symptoms of hypoglycemia, contact your doctor right away or seek medical attention.

Retina Damage

Using Plaquenil long-term or in high doses may lead to permanent vision problems by producing irreversible damage to the layer that lines the back of your eye called a retina. This risk is increased for those who have existing eye conditions, kidney disease or take tamoxifen.

Pediatrics

Plaquenil should be stored out of reach where children cannot access this medication. Children have been reported to be more sensitive to Plaquenil with fatal overdoses, even in small amounts.

Pregnancy

Plaquenil is recommended to treat malaria in pregnant women. Malaria during pregnancy can cause severe adverse outcomes such as premature labor and stillborn.

However, studies have shown that taking Plaquenil while pregnant may pass through to the fetus. Plaquenil should be taken only if the benefits outweigh the risk to the fetus.

Consult with your doctor to evaluate the benefits and risks of taking Plaquenil while pregnant or if you intend to be pregnant while taking Plaquenil.

QT Prolongation

Plaquenil may cause QT prolongation, a condition where the heart takes longer than usual to contract and relax. Your risk increases if you:

• Are taking other medications known to cause QT prolongation.
• Have specific existing heart problems or have a family history of heart problems.
• Have low levels of magnesium or potassium in your blood.
• Are taking diuretics or water pills.
• Have conditions with diarrhea, severe sweating, or vomiting.

Severe Skin Reactions

Severe skin reactions such as toxic epidermal necrolysis can occur when using Plaquenil.

Consult with your doctor immediately if you experience a combination of tarry black stools, diarrhea, painful urination, severe skin rash or acne, mouth ulcers or lesions, peeling or blistering skin, skin lesions or loosening, unusual bruising, or unusual weakness or drowsiness.

Sun Sensitivity

Plaquenil may increase your sensitivity to the sun resulting in more sunburns or skin blisters than usual. Use sunscreen often and limit your time outdoors.

Interactions & Contraindications

Before taking Plaquenil, tell your doctor or pharmacist if you take any medications, herbal supplements, or vitamins. Plaquenil (hydroxychloroquine) can interact with many medications.

Ampicillin

Studies have shown chloroquine may significantly reduce the bioavailability of ampicillin. Ampicillin must be taken at least 2 hours before or after taking Plaquenil.

Antacids And Kaolin

Studies have shown antacids and kaolin may decrease the effect of chloroquine. Antacids must be taken 4 hours before or after taking Plaquenil.

Antiepileptics

Studies have shown antiepileptic drugs may be ineffective while using Plaquenil.

Cimetidine

Taking Plaquenil while using cimetidine interferes with chloroquine resulting in an increased level of chloroquine in the blood. Plaquenil and cimetidine should not be taken together.

Cyclosporine

Cyclosporine plasma levels may be elevated when taking Plaquenil while using cyclosporin. Cyclosporine plasma levels must be monitored when receiving dual therapy.

Diabetic Medications and Insulins

Taking Plaquenil may result in increased efficiency of diabetic medications and insulins. Dosages for diabetic medication and insulins may need to be adjusted.

Digoxin

Serum digoxin levels may be elevated when taking Plaquenil while using digoxin. Serum digoxin levels must be monitored when receiving dual therapy.

Mefloquine and Other Antimalarial Medications

The risk of convulsions may increase when taking Plaquenil with other antimalarial medications such as mefloquine.

Methotrexate

The frequency of adverse effects may increase when taking Plaquenil with methotrexate.

Praziquantel

Taking Plaquenil while using praziquantel may significantly reduce the bioavailability of praziquantel.

The information above does not list all possible interactions and contraindications. Contact your doctor or pharmacist if you experience any interactions not listed.

Frequently Asked Questions