Quinine Sulfate

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.

The US Food and Drug Administration (FDA) warns that quinine should not be used to treat leg cramps. It has not been shown to work for this use and may cause serious side effects. Consult your doctor or pharmacist for more details.

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.

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.

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

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 infection (such as sore throat that doesn't go away, fever, chills), signs of anemia (such as unusual tiredness, brown urine, pale skin, rapid breathing), signs of liver problems (such as nausea/vomiting that doesn't stop, stomach/abdominal pain, yellowing eyes/skin, dark urine), signs of kidney problems (such as change in the amount of urine).

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.

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/safety/medwatch-fda-safety-information-and-adverse-event-reporting-program.

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