Reviewed on 8/27/2021

What Is Quinine and How Does It Work?

Quinine is a prescription drug used as an antimalarial drug indicated only for the treatment of uncomplicated Plasmodium falciparum malaria. Quinine sulfate has been shown to be effective in geographical regions where resistance to chloroquine has been documented.

  • Quinine is available under the following different brand names: Qualaquin.

What Are Dosage of Quinine?

Dosage of Quinine:

Adult and Pediatric Dosages


  • 324 mg

Dosage Considerations – Should be Given as Follows:



Uncomplicated (P. falciparum)

  • 648 mg orally every 8 hours for 7 days

Chloroquine-Resistant (P. falciparum)

Chloroquine-Resistant (P. vivax)

  • 648 mg orally every 8 hours for 3-7 days concomitant doxycycline (or tetracycline) and oral primaquine

Pediatric Dosages

Uncomplicated (P. falciparum)

  • 30 mg/kg/day orally divided three times daily for 3-7 days
  • Should not exceed the usual adult oral dosage

Chloroquine-Resistant (P. falciparum)

  • 30 mg/kg/day orally divided three times daily for 3-7 days, with concomitant doxycycline, tetracycline, or clindamycin
  • Should not exceed the usual adult oral dosage

Chloroquine-Resistant (P. vivax)

  • 30 mg/kg/day orally three times daily for 3-7 days, with concomitant doxycycline and oral primaquine
  • Should not exceed the usual adult oral dosage


Adult Dosage:

  • 648 mg orally every 8 hours, with concomitant orally or intravenously clindamycin

Pediatric Dosage:

  • 25 mg/kg/day orally divided three times daily for 7 days, with concomitant oral clindamycin

Dosage Modifications

  • Severe, chronic renal impairment: 648 mg orally once, then 324 mg orally every 12 hours

Hepatic impairment

  • Mild or moderate (Child-Pugh A or B): No dosage adjustment required; monitor closely
  • Severe (Child-Pugh C): Do not administer


Bowel regularity means a bowel movement every day. See Answer

What Are Side Effects Associated with Using Quinine?

Side effects of quinine include:

  • flushing of the skin
  • chest pain
  • fever
  • rash
  • itching
  • low blood sugar
  • upper abdominal pain
  • rupture of red blood cells in G6PD deficiency
  • low blood platelet count
  • hepatitis
  • night blindness
  • double vision
  • optic nerve deterioration
  • impaired hearing
  • hypersensitivity reaction
  • severe headache
  • nausea
  • vomiting
  • diarrhea
  • blurred vision
  • decreased blood pressure
  • sweating
  • ringing in the ears (tinnitus)
  • spinning sensation (vertigo)
  • distorted color perception
  • abdominal pain
  • deafness
  • blindness
  • irregular heartbeats
  • weakness
  • Lupus-like syndrome
  • deficiency of granulocytes in the blood
  • impaired blood clotting
  • overactive blood clotting
  • destruction of red blood cells
  • abnormal destruction of red blood cells
  • blood disorder causing clotting in small vessels
  • excessive bruising and bleeding
  • small round spots on the skin
  • discoloration of the skin
  • bleeding
  • bleeding disorder
  • severe malaria (blackwater fever)
  • low white blood cell count
  • reduction of red and white blood cells and platelets in the blood
  • no generation of new blood cells
  • lupus anticoagulant
  • confusion
  • altered mental status
  • seizures
  • coma
  • disorientation
  • shakiness
  • restlessness
  • loss of full control of bodily movements
  • acute involuntary contractions of muscles in the face, neck, trunk, pelvis, and extremities
  • communication disorder
  • suicide
  • hives
  • fever, sore throat, and rash (Scarlet Fever)
  • blistering rash
  • red and peeling rash
  • localized eruption of the skin (erythema multiforme)
  • Stevens-Johnson syndrome (SJS)
  • toxic epidermal necrolysis (TEN)
  • oval red skin rash
  • sensitivity to light
  • allergic contact dermatitis
  • black discoloration of the skin
  • inflammation of blood vessels in the skin
  • asthma
  • shortness of breath
  • fluid on the lungs
  • low blood pressure
  • dizziness upon standing
  • fast heart rate
  • slow heart rate
  • strong irregular heartbeat
  • fainting
  • atrioventricular block
  • irregular, fast heart rate
  • extra abnormal heartbeats (unifocal premature ventricular contractions [PVCs])
  • delayed heartbeat
  • U waves (small deflection on ECG)
  • serious irregular heart rhythms (QT prolongation)
  • ventricular fibrillation
  • torsades de pointes
  • cardiac arrest
  • irritation of the stomach
  • irritation of the esophagus
  • granulomatous hepatitis
  • yellowing of eyes and skin (jaundice)
  • abnormal liver function tests
  • loss of appetite
  • muscle pain
  • muscle weakness
  • blood in the urine
  • kidney failure
  • kidney impairment
  • acute kidney inflammation
  • visual disturbances
  • sudden vision loss
  • light sensitivity
  • diminished visual fields
  • fixed dilated pupils
  • inflammation of the optic nerve
  • hearing impairment

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

What Other Drugs Interact with Quinine?

If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

  • Quinine has no known severe interactions with other drugs.
    • Serious interactions of quinine include:
    • cisapride
    • dronedarone
    • eliglustat
    • pimozide
    • thioridazine
  • Quinine has serious interactions with at least 48 different drugs.
  • Quinine has moderate interactions with at least 138 different drugs.
  • Quinine has minor interactions with at least 82 different drugs.

This information does not contain all possible interactions or adverse effects. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions, concerns, or for more information about this medicine.

What Are Warnings and Precautions for Quinine?


  • Limited or no benefit for treatment/prevention of nocturnal leg cramps
  • May cause serious and life-threatening hematologic reactions, including thrombocytopenia and hemolytic uremic syndrome/thrombotic thrombocytopenic purpura (HUS/TTP)
  • Chronic renal impairment associated with the development of TTP has been reported
  • This medication contains quinine. Do not take Qualaquin if you are allergic to quinine or any ingredients contained in this drug
  • Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center immediately


  • Hypersensitivity
  • G6PD deficiency
  • Optic neuritis, tinnitus, history of quinine-associated blackwater fever, and thrombocytopenic purpura
  • Pregnancy

Effects of Drug Abuse

  • No information available

Short-Term Effects

  • See "What Are Side Effects Associated with Using Quinine?"

Long-Term Effects

  • See "What Are Side Effects Associated with Using Quinine?"


  • Reduce parenteral dose by half if over 48-hour parenteral treatment required; monitor EKG, blood pressure, and glucose with parenteral treatment
  • FDA warns against unapproved use for leg cramps because of unpredictable serious and life-threatening hematologic reactions including thrombocytopenia and hemolytic-uremic syndrome/thrombotic thrombocytopenic purpura (HUS/TTP)
  • QT prolongation
  • Concentration-dependent prolongation of the PR and QRS interval observed
  • At particular risk are patients with underlying structural heart disease and preexisting conduction system abnormalities, elderly patients with sick sinus syndrome, patients with atrial fibrillation with the slow ventricular response, patients with myocardial ischemia, or patients receiving drugs known to prolong the PR interval (verapamil) or QRS interval (flecainide or quinidine)

Pregnancy and Lactation

  • Do not use quinine during the first trimester of pregnancy
  • The risks involved outweigh potential benefits
  • Safer alternatives exist
  • Quinine enters breast milk. Consult your physician if breastfeeding


Fungal Skin Infections: Types, Symptoms, and Treatments See Slideshow
Medscape. Quinine.
RxList. Qualaquin Monograph.

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