Chloroquine Phosphate 500 mg Tablet

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor‚s approval.

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.

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), sun sensitivity, 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).

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.

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 cause blurred vision or rarely make you dizzy. Do not drive, use machinery, or do any activity that requires alertness or clear vision until you are sure you can perform such activities safely. Avoid alcoholic beverages.

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. Avoid prolonged sun exposure, tanning booths, and sunlamps. Use a sunscreen and wear protective clothing when outdoors.

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.

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.