chloroquine

What is the most important information I should know about chloroquine?

Taking chloroquine long-term or at high doses may cause irreversible damage to the retina of your eye that could progress to permanent vision problems. You may not be able to use this medicine if you have a history of vision changes or damage to your retina.

What is chloroquine?

Chloroquine is used to treat or prevent malaria, a disease caused by parasites that enter the body through the bite of a mosquito. Chloroquine is not effective against all strains of malaria, or against malaria in areas where the infection has been resistant to a similar drug called hydroxychloroquine.

Chloroquine is also used to treat amebiasis (infection caused by amoebae).

Chloroquine may also be used for purposes not listed in this medication guide.

What should I discuss with my healthcare provider before taking chloroquine?

High doses or long-term use of chloroquine may cause irreversible damage to your retina (the membrane layer inside your eye that helps produce vision). This could progress to permanent vision problems. The risk of retinal damage is higher in people with pre-existing eye problems, kidney disease, or people who also take tamoxifen.

Tell your doctor if you have ever had:

• vision changes or damage to your retina caused by an anti-malaria medication;
• heart disease, heart rhythm disorder (such as long QT syndrome);
• an electrolyte imbalance (such as low levels of potassium or magnesium in your blood);
• diabetes;
• liver or kidney disease;
• psoriasis;
• alcoholism;
• porphyria (a genetic enzyme disorder that causes symptoms affecting the skin or nervous system); or
• a genetic enzyme deficiency called glucose-6-phosphate dehydrogenase (G6PD) deficiency.

It is not known whether chloroquine will harm an unborn baby. If you are pregnant, ask your doctor about the risks of traveling to areas where malaria is common (such as Africa, South America, and Southern Asia).

How should I take chloroquine?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

To prevent malaria: Chloroquine is usually taken once per week on the same day each week. Start taking the medicine 2 weeks before entering an area where malaria is common. Keep taking the medicine during your stay and for at least 8 weeks after you leave the area.

To treat malaria: Chloroquine is usually given as one high dose followed by smaller doses during the next 2 days in a row.

To treat amebiasis: Chloroquine is given in a high starting dose for 2 days followed by a smaller dose for 2 to 3 weeks. You may be given other medications to help prevent further infection.

Chloroquine doses are based on weight in children. Your child's dose needs may change if the child gains or loses weight.

Use this medicine for the full prescribed length of time, even if your symptoms quickly improve.

Use protective clothing, insect repellents, and mosquito netting around your bed to further prevent mosquito bites that could cause malaria.

No medication is 100% effective in treating or preventing all types of malaria. Talk with your doctor if you have fever, vomiting, or diarrhea during your treatment.

While using chloroquine, you may need frequent medical tests and vision exams.

What happens if I miss a dose?

What happens if I overdose?

Overdose symptoms may include drowsiness, vision changes, seizure, slow heart rate, weak pulse, pounding heartbeats, sudden dizziness, fainting, shortness of breath, or slow breathing (breathing may stop).

Keep this medicine out of the reach of children. A chloroquine overdose can be fatal to a child who accidentally swallows this medicine.

What should I avoid while taking chloroquine?

This medicine may cause blurred vision and may impair your reactions. Avoid driving or hazardous activity until you know how this medicine will affect you.

Avoid taking an antacid or Kaopectate (kaolin-pectin) within 4 hours before or 4 hours after you take chloroquine.

What are the possible side effects of chloroquine?

• a seizure;
• ringing in your ears, trouble hearing;
• severe muscle weakness, loss of coordination, underactive reflexes;
• low blood cell counts --fever, chills, tiredness, mouth sores, skin sores, easy bruising, unusual bleeding, pale skin, cold hands and feet, feeling light-headed or short of breath;
• low blood sugar --headache, hunger, sweating, irritability, dizziness, fast heart rate, and feeling anxious or shaky; or
• a serious drug reaction that can affect many parts of your body --skin rash, fever, swollen glands, muscle aches, severe weakness, unusual bruising, or yellowing of your skin or eyes.

• blurred vision, trouble focusing, trouble reading;
• distorted vision, poor night vision;
• changes in your color vision;
• hazy or cloudy vision;
• seeing light flashes or streaks, seeing halos around lights; or
• increased sensitivity to light.

Common side effects may include:

• nausea, vomiting, diarrhea, stomach cramps;
• headache;
• unusual changes in mood or behavior;
• hair loss; or
• changes in hair or skin color.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect chloroquine?

If you take an antibiotic called ampicillin, take it 2 hours before or 2 hours after you take your chloroquine dose.

Tell your doctor about all your other medicines, especially:

• cimetidine;
• cyclosporine;
• mefloquine;
• praziquantel;
• tamoxifen; or
• insulin or oral diabetes medicine.

This list is not complete. Other drugs may affect chloroquine, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Where can I get more information?

Your pharmacist can provide more information about chloroquine.