This medication is used alone or with other medication to 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). Quinine belongs to a class of drugs known as antimalarials. It is not used for the prevention of malaria.

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.

Read the Medication Guide and, if available, the Patient Information Leaflet provided by your pharmacist before you start taking quinine and each time you get a refill. If you have any questions, ask your doctor or pharmacist.

Take this medication by mouth with food (to decrease upset stomach) as directed by your doctor, usually every 8 hours for 3 to 7 days.

Take this medication 2 to 3 hours before or after taking antacids containing aluminum or magnesium. These products bind with quinine, preventing your body from fully absorbing the drug.

The dosage and length of treatment are based on your medical condition, country where you were infected, other medications you may be taking for malaria, and your response to treatment. Children's dosage is also based on weight.

It is very important to keep taking this medication (and other malaria medications) exactly as prescribed by your doctor. Do not take more or less of this drug than prescribed. Do not skip any doses. Continue to take this medication until the full prescribed amount is finished, even if symptoms disappear after a few days. Skipping doses or stopping the medication too early may make the infection more difficult to treat and result in a return of the infection.

This medication works best when the amount of drug in your body is kept at a constant level. Take this drug at evenly spaced intervals. To help you remember, take it at the same times each day.

Tell your doctor if you do not start feeling better after 1 to 2 days of starting this medication. If your fever returns after completing this prescription, contact your doctor so that he/she can determine whether the malaria has returned.

Mild headache, flushing, unusual sweating, nausea, ringing in the ears, decreased hearing, dizziness, blurred vision, and temporary changes in color vision may occur. If any of these effects last after your treatment is finished, or if these effects get worse while taking the medication, tell your doctor or pharmacist promptly.

Quinine may cause low blood sugar (hypoglycemia), especially during pregnancy. Symptoms of low blood sugar include sudden sweating, shaking, fast heartbeat, hunger, blurred vision, dizziness, or tingling hands/feet. If symptoms of low blood sugar occur, increase your blood sugar by eating a quick source of sugar such as table sugar, honey, or candy, or drink fruit juice or non-diet soda. Tell your doctor right away about the reaction and the use of this product.

Remember that this medication has been prescribed because your doctor 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:

• easy bruising/bleeding
• unusual purple/brown/red spots on the skin
• signs of serious infection (such as sore throat that doesn't go away, high fever, severe chills)
• signs of a sudden loss of red blood cells called hemolytic anemia (such as severe tiredness, brown urine, pale lips/nails/skin, rapid breathing at rest)
• signs of severe liver problems (such as nausea/vomiting that doesn't stop, abdominal pain, severe weakness, yellow skin/eyes, unusually dark urine)
• signs of kidney problems (such as change in the amount of urine)

Get medical help right away if you have any very serious side effects, including:

• chest pain
• severe dizziness
• fainting
• fast/irregular heartbeat
• 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

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking quinine, tell your doctor or pharmacist if you are allergic to it; or to quinidine or mefloquine; 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:

• previous serious side effects with quinine (such as blood problems)
• family/personal history of a certain enzyme problem (glucose-6-phosphate dehydrogenase deficiency-G6PD)
• a certain eye nerve problem (optic neuritis)
• hearing problems (such as ringing in the ears)
• a certain nerve/muscle disease (myasthenia gravis)
• heart rhythm problems (such as atrial fibrillation/flutter)
• kidney problems
• liver problems

This drug may make you dizzy or blur your vision. Alcohol or marijuana (cannabis) 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. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).

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

Quinine 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 quinine, 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 quinine safely.

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

During pregnancy, this medication should be used only when clearly needed. Discuss the risks, benefits, and treatment options with your doctor. Untreated malaria is a serious condition that can harm both a pregnant woman and her unborn baby.

This drug passes into breast milk. However, this drug is unlikely to harm some nursing infants. Your doctor will test your infant for a certain enzyme deficiency (glucose-6-phosphate dehydrogenase deficiency-G6PD) before you breastfeed. Consult your doctor before breastfeeding.

See also How to Use section.

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:

• "blood thinners" (such as warfarin)
• penicillamine

Other medications can affect the removal of quinine from your body, which may affect how quinine works. Examples include cimetidine, erythromycin, ketoconazole, phenytoin, rifampin, HIV protease inhibitors (such as lopinavir), ritonavir, urinary alkalinizers such as sodium bicarbonate, among others.

This medication can slow down the removal of other medications from your body, which may affect how they work. Examples of affected drugs include desipramine, digoxin, certain "statin" drugs (atorvastatin, lovastatin, simvastatin), phenobarbital, among others.

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

Quinine is very similar to quinidine. Do not use medications containing quinidine while using quinine.

This medication may interfere with certain lab tests (such as certain urine tests for catecholamines, protein, steroids), possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669. Symptoms of overdose may include: sudden vision change, confusion, severe trouble hearing, fast/irregular heartbeat, fainting, slow/shallow breathing, seizures, inability to wake up (coma).

Do not share this medication with others.

Lab and/or medical tests (such as G6PD blood level, vision tests, blood potassium, liver/kidney function, EKG) may be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.

If you miss a dose, take it as soon as you remember. If it is more than 4 hours after the missed dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.