Generic Name: hydroxychloroquine (hye-drox-ee-KLOR-oh-kwin) (Oral route)
Medically reviewed by Drugs.com. Last updated on Jan 9, 2021.
Commonly used brand name(s)
In the U.S.
Available Dosage Forms:
Therapeutic Class: Antimalarial
Chemical Class: Aminoquinoline
Uses for Plaquenil
Hydroxychloroquine is used to treat malaria. It is also used to prevent malaria infection in areas or regions where it is known that other medicines (eg, chloroquine) may not work. Hydroxychloroquine may also be used to treat coronavirus (COVID-19) in certain hospitalized patients.
Using this medicine alone or with other medicines (eg, azithromycin) may increase your risk of heart rhythm problems (eg, QT prolongation, ventricular fibrillation, ventricular tachycardia). Hydroxychloroquine should only be used for COVID-19 in a hospital or during clinical trials. Do not take any medicine that contains hydroxychloroquine unless prescribed by your doctor.
Hydroxychloroquine belongs to a group of medicines known as antimalarials. It works by preventing or treating malaria, a red blood cell infection transmitted by the bite of a mosquito. However, this medicine is not used to treat severe or complicated malaria.
Hydroxychloroquine is used to treat discoid lupus erythematosus (DLE) or systemic lupus erythematosus (SLE or lupus). It is also used to treat acute and chronic rheumatoid arthritis.
This medicine is available only with your doctor's prescription.
Before using Plaquenil
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Appropriate studies performed to date have not demonstrated pediatric-specific problems that would limit the usefulness of hydroxychloroquine to prevent and treat malaria in children. However, children are more sensitive to the effects of this medicine than adults. Safety and efficacy of hydroxychloroquine to treat lupus and arthritis have not been established in children.
Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of hydroxychloroquine in the elderly. However, elderly patients are more likely to have age-related kidney problems, which may require caution and an adjustment in the dose for patients receiving this medicine.
There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.
Interactions with medicines
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Aripiprazole Lauroxil
- Arsenic Trioxide
- Inotuzumab Ozogamicin
- Insulin Aspart, Recombinant
- Insulin Bovine
- Insulin Degludec
- Insulin Detemir
- Insulin Glulisine
- Insulin Lispro, Recombinant
- Sodium Phosphate
- Sodium Phosphate, Dibasic
- Sodium Phosphate, Monobasic
Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Interactions with food/tobacco/alcohol
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.
Other medical problems
The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:
- Allergy to 4-aminoquinoline compounds (eg, chloroquine)—Should not be used in patients with this condition.
- Blood or bone marrow problems or
- Diabetes or
- Eye or vision problems or
- Muscle problems or
- Nerve problems or
- Porphyria (blood disorder) or
- Psoriasis (skin disease) or
- Stomach or bowel problems–Use with caution. May make these conditions worse.
- Glucose-6-phosphate dehydrogenase (G6PD) deficiency—May cause hemolytic anemia in patients with this condition.
- Kidney disease or
- Liver disease—Use with caution. The effects may be increased because of the slower removal of the medicine from the body.
Proper use of Plaquenil
Take this medicine only as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered.
Swallow the tablet whole. Do not crush, break, or chew it. Take this medicine with meals or milk to lessen stomach upset, unless otherwise directed by your doctor.
Keep using this medicine for the full treatment time, even if you feel better after the first few doses. Your infection may not clear up if you stop using the medicine too soon.
For patients taking hydroxychloroquine to prevent malaria:
- Your doctor may want you to start taking this medicine 1 to 2 weeks before you travel to an area where there is a chance of getting malaria. This will help you to see how you react to the medicine. Also, it will allow time for your doctor to change to another medicine if you have a reaction to this medicine.
- Also, you should keep taking this medicine while you are in the area and for 4 to 6 weeks after you leave the area. No medicine will protect you completely from malaria. However, to protect you as completely as possible, it is important to keep taking this medicine for the full time your doctor ordered. Also, if fever develops during your travels or within 2 months after you leave the area, check with your doctor immediately.
If you are also taking kaolin or antacids, take them at least 4 hours before or after using hydroxychloroquine.
The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
- For oral dosage form (tablets):
- For prevention of malaria:
- Standard dosing: 400 mg once a week on the same day of each week starting 2 weeks before traveling to an area where malaria occurs, and continued for 4 weeks after leaving the area.
- Weight-based dosing: Dose is based on body weight and must be determined by your doctor. At first, 6.5 mg per kilogram (kg) of body weight, not to exceed 400 mg, once weekly on the same day of the week starting 2 weeks before traveling to an area where malaria occurs, and continued for 4 weeks after leaving the area.
- Children—Dose is based on body weight and must be determined by your doctor. At first, 6.5 mg per kilogram (kg) of body weight, not to exceed 400 mg, once weekly on the same day of the week starting 2 weeks before traveling to an area where malaria occurs, and continued for 4 weeks after leaving the area.
- For treatment of malaria:
- Standard dosing: At first, 800 milligrams (mg) (4 tablets) taken as a single dose. Then, 400 mg taken 6 hours, 24 hours, and 48 hours after the first dose.
- Weight-based dosing: Dose is based on body weight and must be determined by your doctor. At first, 13 milligram (mg) per kilogram (kg) of body weight taken as a single dose. Then, 6.5 mg per kg of body weight taken 6 hours, 24 hours, and 48 hours after the first dose. However, dose is usually not more than 800 mg for the first dose and not more than 400 mg for the next doses.
- Children—Dose is based on body weight and must be determined by your doctor. At first, 13 mg per kg of body weight taken as a single dose. Then, 6.5 mg per kg of body weight taken 6 hours, 24 hours, and 48 hours after the first dose. However, dose is usually not more than 800 mg for the first dose and not more than 400 mg for the next doses.
- For treatment of arthritis:
- Adults—At first, 400 to 600 milligrams (mg) taken as a single dose or in two divided doses once a day. Then, 200 to 400 mg taken as a single dose or in two divided doses once a day. Your doctor may adjust your dose if needed. However, dose is usually not more than 600 mg or 6.5 mg per kilogram (kg) of body weight per day, whichever is lower.
- Children—Use and dose must be determined by your doctor.
- For treatment of lupus:
- Adults—200 to 400 milligrams (mg) taken as a single dose or in two divided doses once a day. However, dose is usually not more than 400 mg once a day.
- Children—Use and dose must be determined by your doctor.
- For prevention of malaria:
If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.
Keep out of the reach of children.
Do not keep outdated medicine or medicine no longer needed.
Ask your healthcare professional how you should dispose of any medicine you do not use.
Precautions while using Plaquenil
It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly. Blood and urine tests may be needed to check for unwanted effects.
Check with your doctor immediately if blurred vision, difficulty with reading, or any other change in vision occurs during or after treatment. Your doctor may want your eyes be checked by an ophthalmologist (eye doctor).
Contact your doctor right away if you have any changes to your heart rhythm. You might feel dizzy or faint, or you might have a fast, pounding, or uneven heartbeat. Make sure your doctor knows if you had a heart rhythm problem such as QT prolongation.
This medicine may cause muscle and nerve problems. Check with your doctor right away if you have muscle weakness, pain, or tenderness while using this medicine.
Hydroxychloroquine may cause some people to be agitated, irritable, or display other abnormal behaviors. It may also cause some people to have suicidal thoughts and tendencies, or to become more depressed. If you or your caregiver notice any of these side effects, tell your doctor right away.
This medicine may cause hypoglycemia (low blood sugar). This is more common when this medicine is taken together with certain medicines. Low blood sugar must be treated before it causes you to pass out (unconsciousness). People feel different symptoms of low blood sugar. It is important that you learn which symptoms you usually have so you can treat it quickly. Talk to your doctor about the best way to treat low blood sugar.
Hydroxychloroquine can temporarily lower the number of white blood cells in your blood, increasing the chance of getting an infection. If you can, avoid people with infections. Check with your doctor immediately if you think you are getting an infection or if you get a fever, chills, cough or hoarseness, lower back or side pain, or painful or difficult urination.
Serious skin reactions can occur during treatment with this medicine. Check with your doctor right away if you or your child have any of the following symptoms while using this medicine: blistering, peeling, or loose skin, red skin lesions, severe acne or skin rash, sores or ulcers on the skin, or fever or chills while you are using this medicine.
If your symptoms do not improve within a few days (or a few weeks or months for arthritis), or if they become worse, check with your doctor.
Malaria is spread by the bites of certain kinds of infected female mosquitoes. If you are living in or will be traveling to an area where there is a chance of getting malaria, the following mosquito-control measures will help to prevent infection:
- If possible, avoid going out between dusk and dawn because it is at these times that mosquitoes most commonly bite.
- Remain in air-conditioned or well-screened rooms to reduce contact with mosquitoes.
- Wear long-sleeved shirts or blouses and long trousers to protect your arms and legs, especially from dusk through dawn when mosquitoes are out.
- Apply insect repellant, preferably one containing DEET, to uncovered areas of the skin from dusk through dawn when mosquitoes are out.
- If possible, sleep in a screened or air-conditioned room or under mosquito netting preferably netting coated or soaked with pyrethrum, to avoid being bitten by malaria-carrying mosquitoes.
- Use mosquito coils or sprays to kill mosquitoes in living and sleeping quarters during evening and nighttime hours.
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines) and herbal or vitamin supplements.
Plaquenil side effects
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
Incidence not known
- Blistering, peeling, loosening of the skin
- blurred vision or other vision changes
- chest discomfort, pain, or tightness
- cough or hoarseness
- dark urine
- decreased urination
- defective color vision
- difficulty breathing
- difficulty seeing at night
- dizziness or fainting
- fast, pounding, uneven heartbeat
- feeling that others are watching you or controlling your behavior
- feeling that others can hear your thoughts
- feeling, seeing, or hearing things that are not there
- fever with or without chills
- general feeling of tiredness or weakness
- inability to move the eyes
- increased blinking or spasms of the eyelid
- joint or muscle pain
- large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, and sex organs
- loss of hearing
- lower back or side pain
- noisy breathing
- painful or difficult urination
- red irritated eyes
- red skin lesions, often with a purple center
- severe mood or mental changes
- sore throat sores, ulcers, or white spots on the lips or in the mouth
- sticking out of the tongue
- stomach pain
- swelling of the feet or lower legs
- swollen or painful glands
- trouble with breathing, speaking, or swallowing
- uncontrolled twisting movements of the neck, trunk, arms, or legs
- unusual behavior
- unusual bleeding or bruising
- unusual facial expressions
- unusual tiredness or weakness
- yellow eyes or skin
Symptoms of overdose
- dry mouth
- increased thirst
- loss of appetite
- mood changes
- no pulse or blood pressure
- numbness or tingling in the hands, feet, or lips
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
Incidence not known
- Continuing ringing or buzzing or other unexplained noise in the ears
- feeling of constant movement of self or surroundings
- sensation of spinning
- shakiness and unsteady walk
- uncontrolled eye movements
- unsteadiness, trembling, or other problems with muscle control or coordination
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Frequently asked questions
- An Update: Is hydroxychloroquine effective for COVID-19?
- Does hydroxychloroquine cause emotional lability?
More about Plaquenil (hydroxychloroquine)
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