Generic Name: Chloroquine Brand Name(s): Chloroquine.

Uses

What is Chloroquine used for?

Chloroquine is commonly used to prevent or treat malaria caused by mosquito bites in countries where malaria is common. Malaria parasites can enter the body through these mosquito bites, and then live in body tissues such as red blood cells or the liver. This medication is used to kill the malaria parasites living inside red blood cells. In some cases, you may need to take a different medication (such as primaquine) to kill the malaria parasites living in other body tissues. Both drugs may be needed for a complete cure and to prevent the return of infection (relapse). Chloroquine belongs to a class of drugs known as antimalarials.

The United States Centers for Disease Control provide updated guidelines and travel recommendations for the prevention and treatment of malaria in different parts of the world. Discuss the most recent information with your doctor before traveling to areas where malaria occurs.

Chloroquine is also used to treat infection caused by a different type of parasite (ameba) by killing the ameba.

 How should I take Chloroquine?

Take this medication by mouth, usually with food to prevent stomach upset, exactly as directed by your doctor. Daily or weekly dosing, dosage amount, and length of treatment are based on your medical condition, on whether you are preventing or treating the illness, and your response to treatment. The dosage in children is also based on weight.

To prevent malaria, take chloroquine once weekly on the same day each week, or as directed by your doctor. Start this medication usually 1 to 2 weeks before you enter the malarious area, continue to take it weekly while in the area, and weekly for 4 to 8 weeks after leaving the area, or as directed by your doctor. Mark your calendar or travel schedule with a reminder to help you remember.

To treat malaria infection or an ameba infection, follow your doctor’s instructions.

Take this medication 4 hours before or after taking a certain drug for diarrhea (kaolin) or taking antacids (such as magnesium/aluminum hydroxide). These products may bind with chloroquine, preventing your body from fully absorbing the drug.

It is very important to continue taking this medication exactly as prescribed by your doctor. Do not take more or less of this drug than prescribed. Do not stop taking it before completing treatment, even if you feel better, unless directed to do so by your doctor. Skipping or changing your dose without approval from your doctor may cause prevention/treatment to be ineffective, cause the amount of parasite to increase, make the infection more difficult to treat (resistant), or worsen side effects.

It is important to prevent mosquito bites (such as by using appropriate insect repellents, wearing clothes that cover most of the body, remaining in air-conditioned or well-screened areas, using mosquito nets and insect-killing spray). Buy insect repellent before traveling. The most effective insect repellents contain diethyltoluamide (DEET). Ask your doctor or pharmacist to recommend the appropriate strengths of mosquito repellent for you/your children.

No drug treatment is completely effective in preventing malaria. Therefore, seek immediate medical attention if you develop symptoms of malaria (such as fever, chills, headache, other flu-like symptoms), especially while in the malarious area and for 2 months after completing this prescription. Quick treatment of malaria infection is needed to prevent serious, possibly fatal, outcomes.

When using chloroquine for treatment of malaria, tell your doctor if your condition persists or worsens.

How do I store Chloroquine?

Chloroquine is best stored at room temperature away from direct light and moisture. To prevent drug damage, you should not store Chloroquine in the bathroom or the freezer. There may be different brands of Chloroquine that may have different storage needs. It is important to always check the product package for instructions on storage, or ask your pharmacist. For safety, you should keep all medicines away from children and pets.

You should not flush Chloroquine down the toilet or pour them into a drain unless instructed to do so. It is important to properly discard this product when it is expired or no longer needed. Consult your pharmacist for more details about how to safely discard your product.

Precautions & warnings

What should I know before using Chloroquine?

Before taking chloroquine, tell your doctor or pharmacist if you are allergic to it; or to hydroxychloroquine; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: a certain enzyme problem (glucose-6-phosphate dehydrogenase deficiency-G6PD), vision/eye problems, hearing problems, kidney disease, liver disease, regular alcohol use/abuse, psoriasis, a certain blood disorder (porphyria), seizures.

This drug may blur your vision or rarely make you dizzy. Alcohol or marijuana can make you more dizzy. Do not drive, use machinery, or do anything that needs alertness or clear vision until you can do it safely. Avoid alcoholic beverages. Talk to your doctor if you are using marijuana.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

This medication may make you more sensitive to the sun. Limit your time in the sun. Avoid tanning booths and sunlamps. Use sunscreen and wear protective clothing when outdoors. Tell your doctor right away if you get sunburned or have skin blisters/redness.

Chloroquine may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can rarely cause serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that need medical attention right away.

The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may cause QT prolongation. Before using chloroquine, tell your doctor or pharmacist of all the drugs you take and if you have any of the following conditions: certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG), family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death).

Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/”water pills”) or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about using chloroquine safely.

If you have diabetes, this product may affect your blood sugar. Check your blood sugar regularly as directed and share the results with your doctor. Tell your doctor right away if you have symptoms of low blood sugar (see Side Effects section). Your doctor may need to adjust your diabetes medication, exercise program, or diet.

Older adults may be more sensitive to the side effects of this drug, especially eye/vision problems and QT prolongation (see above).

During pregnancy, this medication should be used only when clearly needed. It may harm an unborn baby. While you are pregnant, traveling to an area with malaria places you and your infant at much higher risk of death and other problems. Discuss the risks and benefits of malaria prevention with your doctor.

This drug passes into breast milk and the effect on a nursing infant is unknown. Discuss the risks and benefits with your doctor before breast-feeding.

Is it safe during pregnancy or breast-feeding?

There are no adequate studies in women for determining risk when using this Chloroquine during pregnancy or while breastfeeding. Please always consult with your doctor to weigh the potential benefits and risks before taking this Chloroquine. This Chloroquine is pregnancy risk category N according to the US Food and Drug Administration (FDA).

FDA pregnancy risk category reference below:

  • A=No risk,
  • B=No risk in some studies,
  • C=There may be some risk,
  • D=Positive evidence of risk,
  • X=Contraindicated,
  • N=Unknown

Side effects

What side effects can occur from Chloroquine?

Blurred vision, nausea, vomiting, abdominal cramps, headache, and diarrhea may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including: bleaching of hair color, hair loss, mental/mood changes (such as confusion, personality changes, unusual thoughts/behavior, depression), hearing changes (such as ringing in the ears, hearing loss), darkening of skin/tissue inside the mouth, worsening of skin conditions (such as dermatitis, psoriasis), signs of serious infection (such as high fever, severe chills, persistent sore throat), unusual tiredness, swelling legs/ankles, shortness of breath, pale lips/nails/skin, signs of liver disease (such as severe stomach/abdominal pain, yellowing eyes/skin, dark urine), easy bruising/bleeding, muscle weakness, unwanted/uncontrolled movements (including tongue and face twitching).

This medication may rarely cause low blood sugar (hypoglycemia). Tell your doctor right away if you develop symptoms of low blood sugar, such as sudden sweating, shaking, hunger, blurred vision, dizziness, or tingling hands/feet. If you have diabetes, be sure to check your blood sugars regularly. Your doctor may need to adjust your diabetes medication.

Get medical help right away if you have any very serious side effects, including: severe dizziness, fainting, fast/slow/irregular heartbeat, seizures.

This medication may cause serious eye/vision problems. The risk for these side effects is increased with long-term use of this medication (over weeks to years) and with taking this medication in high doses. Get medical help right away if you have any symptoms of serious eye problems, including: severe vision changes (such as light flashes/streaks, difficulty reading, complete blindness).

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

Not everyone experiences these side effects. There may be some side effects not listed above. If you have any concerns about a side-effect, please consult your doctor or pharmacist.

Interactions

What drugs may interact with Chloroquine?

Some products that may interact with this drug include: agalsidase, mefloquine, penicillamine, sulfadoxine/pyrimethamine, products that may harm the liver (such as acetaminophen, isoniazid, alcohol).

This medication can speed up or slow down the removal of other medications from your body, which may affect how they work. An example of an affected drug is praziquantel, among others.

Many drugs besides chloroquine may affect the heart rhythm (QT prolongation), including amiodarone, dofetilide, mefloquine, pimozide, procainamide, quinidine, sotalol, macrolide antibiotics (such as erythromycin), among others. Therefore, before using chloroquine, report all medications you are currently using to your doctor or pharmacist.

Cimetidine is a nonprescription drug that is commonly used to treat extra stomach acid. Because cimetidine and other antacids may interact with chloroquine, ask your pharmacist about other products to treat extra stomach acid.

Take chloroquine at least 2 hours before or after taking ampicillin. Chloroquine may decrease the amount of ampicillin in your body and the ampicillin may not work as well.

Certain vaccines (rabies vaccine, cholera vaccine) may not work as well if given while you are taking chloroquine. Ask your doctor for more details.

Chloroquine may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs and herbal products) and share it with your doctor and pharmacist. For your safety, do not start, stop, or change the dosage of any drugs without your doctor’s approval.

Does food or alcohol interact with Chloroquine?

Chloroquine may interact with food or alcohol by altering the way the drug works or increase the risk for serious side effects. Please discuss with your doctor or pharmacist any potential food or alcohol interactions before using this drug.

What health conditions may interact with Chloroquine?

Chloroquine may interact with your health condition. This interaction may worsen your health condition or alter the way the drug works. It is important to always let your doctor and pharmacist know all the health conditions you currently have.

Dosage

The information provided is not a substitute for any medical advice. You should ALWAYS consult with your doctor or pharmacist before using this Chloroquine.

What is the dose of Chloroquine for an adult?

Usual Adult Dose for Malaria Prophylaxis

500 mg chloroquine phosphate (300 mg base) orally on the same day each week

Comments:
-If possible, suppressive therapy should start 2 weeks prior to exposure; if unable to start 2 weeks before exposure, an initial loading dose of 1 g chloroquine phosphate (600 mg base) may be taken orally in 2 divided doses, 6 hours apart.
-Suppressive therapy should continue for 8 weeks after leaving the endemic area.

Approved indication: For the suppressive treatment of malaria due to Plasmodium vivax, P malariae, P ovale, and susceptible strains of P falciparum

CDC Recommendations:
300 mg base (500 mg salt) orally once a week

Comments:
-For prophylaxis only in areas with chloroquine-sensitive malaria
-Prophylaxis should start 1 to 2 weeks before travel to malarious areas; should continue weekly (same day each week) while in malarious areas and for 4 weeks after leaving such areas.

Usual Adult Dose for Malaria

60 kg or more: 1 g chloroquine phosphate (600 mg base) orally as an initial dose, followed by 500 mg chloroquine phosphate (300 mg base) orally after 6 to 8 hours, then 500 mg chloroquine phosphate (300 mg base) orally once a day on the next 2 consecutive days
Total dose: 2.5 g chloroquine phosphate (1.5 g base) in 3 days

Less than 60 kg:
First dose: 16.7 mg chloroquine phosphate/kg (10 mg base/kg) orally
Second dose (6 hours after first dose): 8.3 mg chloroquine phosphate/kg (5 mg base/kg) orally
Third dose (24 hours after first dose): 8.3 mg chloroquine phosphate/kg (5 mg base/kg) orally
Fourth dose (36 hours after first dose): 8.3 mg chloroquine phosphate/kg (5 mg base/kg) orally
Total dose: 41.7 mg chloroquine phosphate/kg (25 mg base/kg) in 3 days

Comments:
-Concomitant therapy with an 8-aminoquinoline compound is necessary for radical cure of malaria due to P vivax and P malariae.

Approved indication: For acute attacks of malaria due to P vivax, P malariae, P ovale, and susceptible strains of P falciparum

CDC Recommendations:
Chloroquine-sensitive uncomplicated malaria (Plasmodium species or species not identified): 600 mg base (1 g salt) orally at once, followed by 300 mg base (500 mg salt) orally at 6, 24, and 48 hours
Total dose: 1.5 g base (2.5 g salt)

Comments:
-For the treatment of uncomplicated malaria due to chloroquine-sensitive P vivax or P ovale, concomitant treatment with primaquine phosphate is recommended.
-Current guidelines should be consulted for additional information.

Usual Adult Dose for Amebiasis

1 g chloroquine phosphate (600 mg base) orally once a day for 2 days, followed by 500 mg chloroquine phosphate (300 mg base) orally once a day for at least 2 to 3 weeks

Comments:
-Treatment is usually combined with an effective intestinal amebicide.

Approved indication: For the treatment of extraintestinal amebiasis

Usual Adult Dose for Sarcoidosis

(Not approved by FDA)

Study (n=43)
Intrathoracic and cutaneous: 250 mg twice a day for 4 to 17 months; a treatment course should be limited to 6 months to minimize risk of ocular damage

Study (n=23)
Pulmonary: 750 mg per day for 6 months, then tapered every 2 months to 250 mg per day

Study (n=37)
Nervous system (neurosarcoidosis): 250 mg twice a day for 6 to 18 months

Liver Dose Adjustments

Caution recommended in patients with hepatic disorders, alcoholism, or with concomitant hepatotoxic agents.

Precautions

Consult WARNINGS section for dosing related precautions.

Dialysis

Hemodialysis and peritoneal dialysis: Data not available

Comments:
-Peritoneal dialysis has been suggested to reduce the level of the drug in the blood.

Other Comments

General:
-The dose of chloroquine is often expressed or calculated as the base: each 500 mg tablet of chloroquine phosphate is equivalent to 300 mg chloroquine base.
-The pediatric dose should never exceed the adult dose.

Monitoring:
-Hematologic: Complete blood cell counts (periodically, if prolonged therapy)
-Musculoskeletal: For signs of muscular weakness (if prolonged therapy); knee and ankle reflexes (if prolonged therapy)
-Ocular: Ophthalmologic examinations, including visual acuity, expert slit-lamp, funduscopic, visual field tests (at baseline and periodically, if prolonged therapy considered)
-Renal: Renal function in patients with renal dysfunction

What is the dose of Chloroquine for a child?

Usual Pediatric Dose for Malaria Prophylaxis

Infants and children: 8.3 mg chloroquine phosphate/kg (5 mg base/kg) orally on the same day each week

Comments:
-Pediatric dose should not exceed the adult dose regardless of weight.
-If possible, suppressive therapy should start 2 weeks prior to exposure; if unable to start 2 weeks before exposure, an initial loading dose of 16.7 mg chloroquine phosphate/kg (10 mg base/kg) may be taken orally in 2 divided doses, 6 hours apart.
-Suppressive therapy should continue for 8 weeks after leaving the endemic area.

Approved indication: For the suppressive treatment of malaria due to P vivax, P malariae, P ovale, and susceptible strains of P falciparum

CDC Recommendations:
5 mg base/kg (8.4 mg salt/kg) orally once a week
Maximum dose: 300 mg base/dose (500 mg salt/dose)

Comments:
-For prophylaxis only in areas with chloroquine-sensitive malaria
-Prophylaxis should start 1 to 2 weeks before travel to malarious areas; should continue weekly (same day each week) while in malarious areas and for 4 weeks after leaving such areas.

Usual Pediatric Dose for Malaria

Infants and children:
Less than 60 kg:
First dose: 16.7 mg chloroquine phosphate/kg (10 mg base/kg) orally
Second dose (6 hours after first dose): 8.3 mg chloroquine phosphate/kg (5 mg base/kg) orally
Third dose (24 hours after first dose): 8.3 mg chloroquine phosphate/kg (5 mg base/kg) orally
Fourth dose (36 hours after first dose): 8.3 mg chloroquine phosphate/kg (5 mg base/kg) orally
Total dose: 41.7 mg chloroquine phosphate/kg (25 mg base/kg) in 3 days

60 kg or more:
First dose: 1 g chloroquine phosphate (600 mg base) orally
Second dose (6 hours after first dose): 500 mg chloroquine phosphate (300 mg base) orally
Third dose (24 hours after first dose): 500 mg chloroquine phosphate (300 mg base) orally
Fourth dose (36 hours after first dose): 500 mg chloroquine phosphate (300 mg base) orally
Total dose: 2.5 g chloroquine phosphate (1.5 g base) in 3 days

Comments:
-Concomitant therapy with an 8-aminoquinoline compound is necessary for radical cure of malaria due to P vivax and P malariae.

Approved indication: For acute attacks of malaria due to P vivax, P malariae, P ovale, and susceptible strains of P falciparum

CDC Recommendations:
Chloroquine-sensitive uncomplicated malaria (Plasmodium species or species not identified): 10 mg base/kg orally at once, followed by 5 mg base/kg orally at 6, 24, and 48 hours
Total dose: 25 mg base/kg

Comments:
-Pediatric dose should never exceed adult dose.
-For the treatment of uncomplicated malaria due to chloroquine-sensitive P vivax or P ovale, concomitant treatment with primaquine phosphate is recommended.
-Current guidelines should be consulted for additional information.

 How is Chloroquine available?

Chloroquine is available in the following dosage forms and strengths:

  • Tablet

What should I do in case of an emergency or overdose?

In case of an emergency or an overdose, call your local emergency services or go to your nearest emergency room.

What should I do if I miss a dose?

If you miss a dose of Chloroquine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose.

Hello Health Group does not provide medical advice, diagnosis or treatment.

Sources

Review Date: January 16, 2018 | Last Modified: January 16, 2018

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