How does this medication work? What will it do for me?

Quinine belongs to the class of medications known as antimalarials. It is used along with one other medication (usually an antibiotic) to treat certain types of malaria.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. As well, some forms of this medication may not be used for all of the conditions discussed here. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

What form(s) does this medication come in?

This medication is available as 200 mg and 300 mg capsules.

How should I use this medication?

For treatment of malaria, the average recommended daily adult dose of quinine is 600 mg 3 times daily, taken after meals, for 3 to 7 days. Children's doses are calculated according to body weight.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose or dosing schedule different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important to take this medication exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Who should NOT take this medication?

Quinine should not be taken by anyone who:

  • is allergic to quinine or to any of the ingredients of the medication
  • is pregnant (unless quinine is required to treat a severe, life-threatening malaria infection in the mother)
  • has a glucose-6-phosphate dehydrogenase deficiency
  • has a history of blackwater fever and thrombocytopenic purpura (purplish discoloration of skin)
  • has low blood sugar
  • has myasthenia gravis
  • has optic neuritis
  • has tinnitus (ringing in the ears)

What side effects are possible with this medication?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent. The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

  • abdominal or stomach cramps or pain
  • diarrhea
  • nausea
  • vomiting

Although most of these side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

  • anxiety
  • blood in urine or stools
  • blurred vision
  • change in colour perception
  • cold sweats
  • confusion
  • cool, pale skin
  • difficulty concentrating
  • double vision
  • drowsiness
  • excessive hunger
  • fever or chills
  • flushing or redness of skin
  • headache
  • increased sweating
  • nervousness
  • pinpoint-sized red spots on skin
  • restless sleep
  • ringing or buzzing in ears
  • shakiness
  • unusual bleeding or bruising
  • unusual tiredness or weakness

Stop taking the medication and seek immediate medical attention if any of the following occur:

  • abnormal heart rhythms (e.g., very fast or slow heart rate)
  • breathing or swallowing difficulties, or hives
  • convulsions or coma
  • night blindness
  • swelling of eyes, face, or inside of nose

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Are there any other precautions or warnings for this medication?

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Diabetes: Quinine may lower blood sugar levels. People with diabetes who take this medication should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Heart disease: Quinine may cause side effects that affect the heart, but usually only at high doses. People with heart disease should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Pregnancy: Quinine may cause birth defects. It should be used during pregnancy only when required to treat a severe case of life-threatening malaria.

Breast-feeding: Quinine passes into breast milk. No harmful effects have been reported in healthy infants exposed to quinine through breast milk. If you are a breast-feeding mother and are taking quinine, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

What other drugs could interact with this medication?

There may be an interaction between quinine and any of the following:

  • acetazolamide
  • antacids
  • cimetidine
  • dapsone
  • digoxin
  • macrolide antibiotics (e.g., azithromycin, clarithromycin, erythromycin)
  • medications that can affect the heart rhythm (e.g., amiodarone, pimozide, sotalol)
  • mefloquine
  • neuromuscular blockers (e.g., succinylcholine, pancuronium)
  • rifabutin
  • rifampin
  • sodium bicarbonate
  • statin medications (e.g., atorvastatin, lovastatin, simvastatin)
  • tamoxifen
  • warfarin

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

  • stop taking one of the medications,
  • change one of the medications to another,
  • change how you are taking one or both of the medications, or
  • leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.