quinine sulfate at a glance
Medicine class
Cinchona alkaloid and antiprotozoal agent.
Licensed uses
Falciparum malaria; nocturnal leg cramps that disrupt sleep in adults and older people.
Administration
Film-coated tablets are swallowed with water.
What is quinine sulfate used for?
The selected product is licensed for:
Treatment of falciparum malaria.
Treatment and prevention of nocturnal leg cramps in adults and older people when cramps regularly disrupt sleep.
How does quinine sulfate work?
Quinine acts rapidly against malaria parasites in red blood cells. It also affects signalling between nerves and skeletal muscle, which may contribute to its effect on cramps.
quinine sulfate preparations and strengths
Tablet
Route: Oral
Strengths: 200 mg, 300 mg
How to take quinine sulfate
Take quinine sulfate exactly as prescribed and do not exceed the prescribed amount. Swallow film-coated tablets with water. If ringing in the ears, impaired hearing, headache, nausea or visual disturbance develops, stop taking it and contact a clinician promptly.
Do not share prescribed tablets.
Do not drive or use machinery if vision changes or vertigo occur.
quinine sulfate side effects
Common or expected effects
- Nausea, vomiting, diarrhoea and abdominal pain may occur.
- Headache, dizziness, flushing, rash, ringing in the ears, impaired hearing and visual disturbance may occur.
- Low blood sugar can occur, particularly in susceptible people.
Get urgent medical advice
- Unexplained bruising or bleeding may indicate severe thrombocytopenia.
- Facial or throat swelling, wheezing or breathing difficulty may indicate serious hypersensitivity.
- Blistering skin or sores affecting the mouth, eyes or genitals may indicate Stevens–Johnson syndrome.
- Fainting, palpitations or marked dizziness may indicate a heart-rhythm disturbance.
- Severe visual loss, seizures, confusion, loss of consciousness, reduced urine output or profound muscle weakness need urgent assessment.
quinine sulfate in pregnancy
Quinine sulfate should not be used for leg cramps during pregnancy. It may be used for malaria when a specialist considers it the best treatment; use later in pregnancy has been associated with maternal hypoglycaemia. Discuss pregnancy or planned pregnancy with the prescriber.
quinine sulfate while breastfeeding
Quinine passes into breast milk, but infant exposure is generally low. The selected product advises use only when benefits outweigh risks. Breastfeeding should be avoided if the baby has, or may have, G6PD deficiency until this is clarified.
quinine sulfate interactions
A medication review is important because quinine can affect medicine concentrations, bleeding risk, blood glucose and cardiac conduction.
Medicines that prolong the QT interval
Can increase the risk of dangerous ventricular arrhythmias.
Strong CYP3A4 inhibitors, including azole antifungals and HIV protease inhibitors
May raise quinine exposure and toxicity.
Rifampicin, phenytoin, carbamazepine and barbiturates
May reduce quinine concentrations and effectiveness.
Common questions about quinine sulfate
Answers are fully visible for fast scanning and source review.
Why is quinine sulfate not routinely used for night cramps?
Its average benefit is modest, while rare reactions such as severe thrombocytopenia and serious interactions can be life-threatening.
Can quinine sulfate affect hearing or eyesight?
Yes. Ringing in the ears, impaired hearing and visual disturbances can occur. Severe or persistent symptoms need prompt assessment.
Can quinine sulfate affect heart rhythm?
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.