Quinine is used to treat malaria, a disease caused by parasites. Parasites that cause malaria typically enter the body through the bite of a mosquito. Malaria is common in areas such as Africa, South America, and Southern Asia.

Quinine will not treat severe forms of malaria, and it should not be taken to prevent malaria. Quinine also should not be taken to treat or prevent night-time leg cramps.

Using this medication improperly or without the advice of a doctor can result in serious side effects or death. Quinine is approved for use only in treating malaria. Some people have used quinine to treat leg cramps, but this is not an FDA-approved use.

The U.S. Food and Drug Administration has banned the sale of all non-approved brands of quinine. As of December 2006, Qualaquin is the only brand of quinine that is approved by the FDA.

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

You should not take quinine if you have a heart rhythm disorder called Long QT syndrome, G-6-PD (an enzyme deficiency), a blood clotting disorder, myasthenia gravis, or optic neuritis (inflammation of the nerves in your eyes).

Some people have used quinine to treat leg cramps, but this is not an FDA-approved use. Using this medication improperly or without the advice of a doctor can result in serious side effects or death. The U.S. Food and Drug Administration has banned the sale of all non-approved brands of quinine. Do not purchase quinine on the Internet or from vendors outside of the United States.

Do not use this medication if you have ever had an allergic reaction to quinine or similar medicines such as mefloquine (Lariam) or quinidine (Cardioquin, Quinidex, Quinaglute, Quin-G).

Before taking quinine, tell your doctor if you have heart disease or a heart rhythm disorder, low potassium levels in your blood (hypokalemia), kidney disease, or liver disease.

Many drugs can interact with quinine and some should not be used at the same time. Tell your doctor about all medications you use. Do not start a new medication without telling your doctor.

Do not use this medication if you have ever had an allergic reaction to quinine or similar medicines such as mefloquine (Lariam) or quinidine (Cardioquin, Quinidex, Quinaglute, Quin-G), or if you have:

• a heart rhythm disorder called Long QT syndrome;

• an enzyme deficiency called glucose-6-phosphate dehydrogenase (G-6-PD) deficiency;

• a blood clotting disorder;

• myasthenia gravis; or

• optic neuritis (inflammation of the optic nerve).

To make sure you can safely take quinine, tell your doctor if you have any of these other conditions:

• heart disease or a heart rhythm disorder;

• low potassium levels in your blood (hypokalemia); or

• kidney or liver disease.

FDA pregnancy category C. It is not known whether quinine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication..

Hypoglycemia (low blood sugar) may be more likely to occur in pregnant women who are taking quinine. Signs of low blood sugar include headache, hunger, weakness, sweating, tremors, irritability, or trouble concentrating. Talk to your doctor about your specific risk for low blood sugar if you take quinine while you are pregnant.

Quinine can pass into breast milk and may harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

Do not give this medication to a child younger than 16 years old.