Quinine is a medication used to treat malaria and babesiosis.
This includes the treatment of malaria due to Plasmodium falciparum that is resistant to chloroquine.
It is sometimes used for restless legs syndrome, it is not recommended for this purpose due to the risk of serious side effects.
It can be taken by mouth or intravenously.
It is also the ingredient in tonic water that gives it its bitter taste.
Pregnancy category US: N (Not classified yet).
Protein binding 70–95%.
Metabolism is hepatic mostly CYP3A4 and CYP2C19-mediated.
Elimination half-life 8–14 hours in adults, and 6–12 hours in children.
Excretion Kidney 20%.
Common side effects include headache, ringing in the ears, trouble seeing, and sweating.
More severe side effects include: deafness, thrombocytopenia, and an arrhythmia.
It increases propensity to sunburn.
No longer recommended by the World Health Organization (WHO) as a first-line treatment for malaria, because there are other substances that are equally effective with fewer side effects.
Quinine was frequently prescribed treatment for leg cramps at night, but is associated with life-threatening side effects.
Commercially available in 324-mg tablets.
All quinine salts may be given orally or intravenously (IV), and quinine gluconate may also be given intramuscularly or rectally.
The quinine content of tonic water causes it to fluoresce under black light.
Quinine is a flavor component of tonic water and bitter lemon drink mixers.
Commonly causes drug-induced disorders: including thrombocytopenia and thrombotic microangiopathy, immune system effects and fever, hypotension, hemolytic anemia, acute kidney injury, liver toxicity, and blindness.
In patients with atrial fibrillation, conduction defects, or heart block, quinine can cause heart arrhythmias, and should be avoided.
It can cause hemolysis in G6PD deficiency, but this risk is small.
Can cause life-threatening blood and cardiovascular reactions including low platelet count and hemolytic-uremic syndrome/thrombotic thrombocytopenic purpura (HUS/TTP), long QT syndrome and other serious cardiac arrhythmias including torsades de pointes, blackwater fever, disseminated intravascular coagulation, leukopenia, and neutropenia.
TTP induced by quinine may result in kidney failure.
Quinine can also cause hypersensitivity reactions include anaphylactic shock, urticaria, serious skin rashes, including Stevens–Johnson syndrome and toxic epidermal necrolysis, angioedema, facial edema, bronchospasm, granulomatous hepatitis, and itchiness.
Cinchonism refers to a group of its side effects: headache, vasodilation and sweating, nausea, tinnitus, hearing impairment, vertigo or dizziness, blurred vision, and disturbance in color perception.
Advanced cinchonism includes: vomiting, diarrhea, abdominal pain, deafness, blindness, and disturbances in heart rhythms.
Cinchonism is much less common when quinine is given by mouth
Oral quinine is not well tolerated and many people will vomit after ingesting quinine tablets.
Quinine has the potentiating the anticoagulant effects of warfarin.
In Plasmodium falciparum malaria it is used to interfere with the parasite’s ability to dissolve and metabolize hemoglobin.
As with other antimalarial drugs, the precise mechanism of action of quinine has not been fully resolved, but thought to inhibit nucleic acid and protein synthesis, and inhibits glycolysis in P. falciparum.
Quinine is highly fluorescent.
Cinchona trees are the only natural source of quinine, but
chemical synthesis has been accomplished.
During World War II tens of thousands of US troops in Africa and the South Pacific died of malaria due to the lack of quinine.
Quinine as an antimalarial drug has been replaced by drugs that have fewer side effects, such as chloroquine.
The bark of Remijia contains 0.5–2% of quinine, and it is used for making tonic water.
In 1994, the FDA banned the marketing of over-the-counter quinine as a treatment for nocturnal leg cramps.
Quinine is approved for treatment of malaria, but was also commonly prescribed to treat leg cramps and similar conditions.