In the human liver cancer HepG2 cell line, quinine (150 μM, 30 min) suppresses the growth and cytostatic effects of dengue virus [1]. In the human liver cancer HepG2 cell line, quinine (37.5-150 μM, 24 hours) greatly lowers viral DENV RNA and protein levels in a dose-dependent manner [1].

Swiss albino mice treated with quinine (gavated, 12 or 15 mg/kg, weekly, 16 weeks) show some inhibitory effects against skin cancer [2]. In the testicular tissue of adult male albino rats, quinine (gavage, 10 mg/kg, daily, 8 weeks) reduces the activity of the antioxidant defense system's SOD, CAT, and GSH enzymes [3].

Cell Proliferation Assay[1]
Cell Types: Human hepatocarcinoma cell line (HepG2)
Tested Concentrations: 150 μM
Incubation Duration: 30 min
Experimental Results: Inhibited DENV virus replication with 19% yield compared to untreated. decreased DENV-positive cells from 23.28% to 12.05% in a dose-dependent manner.

Animal/Disease Models: Swiss albino mice 7-8-weeks (weighing 24 g)[2]
Doses: 12 mg/kg, 15 mg/kg
Route of Administration: po (oral gavage); every week; 16 weeks
Experimental Results: Resulted in a significant reduction in tumor size and weight at 12 mg/kg and little effect at higher dose of 15 mg/kg.

Absorption, Distribution and Excretion
76 - 88%
Quinine is eliminated primarily via hepatic biotransformation. Approximately 20% of quinine is excreted unchanged in urine.
1.43 ± 0.18 L/kg [Healthy Pediatric Controls]
0.87 ± 0.12 L/kg [P. falciparum Malaria Pediatric Patients]
2.5 to 7.1 L/kg [healthy subjects who received a single oral 600 mg dose]
0.17 L/h/kg [healthy]
0.09 L/h/kg [patients with uncomplicated malaria]
18.4 L/h [healthy adult subjects with administration of multiple-dose activated charcoal]
11.8 L/h [healthy adult subjects without administration of multiple-dose activated charcoal]
Oral cl=0.06 L/h/kg [elderly subjects]
Following oral administration of a single 600-mg dose of quinine sulfate in healthy adults, the mean plasma clearance was 0.08-0.47 L/hour per kg (median: 0.17 L/hour per kg) and the mean plasma elimination half-life was 9.7-12.5 hours. Following oral administration of 10 mg/kg of quinine sulfate in patients with uncomplicated malaria, mean total clearance of quinine was decreased (approximately 0.09 L/hour per kg) during the acute phase of the infection and increased (approximately 0.16 L/hour per kg) during the recovery or convalescent phase.
Following oral administration of a single 600-mg dose of quinine sulfate in geriatric and younger adults, the mean clearance of the drug was decreased (0.06 versus 0.08 L/hour per kg) and the mean elimination half-life was significantly increased (18.4 versus 10.5 hours) in geriatric adults compared with younger adults. Although renal clearance of quinine was similar in geriatric and younger adults, geriatric adults excreted a larger proportion of the dose in urine as unchanged drug compared with younger adults (16.6 versus 11.2%). The steady-state pharmacokinetics after a quinine sulfate dosage of 648 mg 3 times daily for 7 days were similar in healthy geriatric adults 65-78 years of age and healthy younger adults 20-39 years of age; however, the mean elimination half-life was 24 hours in the geriatric individuals compared with 20 hours in the younger adults.
Following oral administration of a single dose of 10 mg/kg of quinine sulfate in healthy children or pediatric patients 1.5-12 years of age with uncomplicated Plasmodium falciparum malaria, the mean total clearance (0.06 versus 0.3 L/hour per kg) is reduced and the plasma elimination half-life increased (12.1 versus 3.21 hours) in pediatric patients with malaria as compared to that observed in healthy children.
In 15 patients with uncomplicated malaria who received a 10 mg/kg oral dose of quinine sulfate, the mean total clearance of quinine was slower (approximately 0.09 L/hr/kg) during the acute phase of the infection, and faster (approximately 0.16 L/hr/kg) during the recovery or convalescent phase.
For more Absorption, Distribution and Excretion (Complete) data for QUININE (19 total), please visit the HSDB record page.

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Metabolism / Metabolites
Hepatic, over 80% metabolized by the liver.
In vitro studies using human liver microsomes and recombinant P450 enzymes have shown that quinine is metabolized mainly by CYP3A4. Depending on the in vitro experimental conditions, other enzymes, including CYP1A2, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP2E1 were shown to have some role in the metabolism of quinine.
Quinine is metabolized almost exclusively via hepatic oxidative cytochrome P450 (CYP) pathways, resulting in four primary metabolites, 3-hydroxyquinine, 2'-quinone, O-desmethylquinine, and 10,11-dihydroxydihydroquinine. Six secondary metabolites result from further biotransformation of the primary metabolites. The major metabolite, 3-hydroxyquinine, is less active than the parent drug.
Quinine has known human metabolites that include 3-Ethenyl-6-[hydroxy-(6-methoxyquinolin-4-yl)methyl]-1-azabicyclo[2.2.2]octan-3-ol.
Hepatic, over 80% metabolized by the liver.
Route of Elimination: Quinine is eliminated primarily via hepatic biotransformation. Approximately 20% of quinine is excreted unchanged in urine.
Half Life: Approximately 18 hours

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Biological Half-Life
Approximately 18 hours
Compared with administration of quinine alone, administration of a single 600-mg dose of quinine sulfate in healthy individuals who were receiving ritonavir (200 mg every 12 hours) resulted in an increased quinine mean elimination half-life (11.2 hours versus 13.4 hours).
The plasma elimination half-life of quinine reportedly averages 8-21 hours in adults with malaria and 7-12 hours in healthy or convalescing adults.
The steady-state pharmacokinetics after a quinine sulfate dosage of 648 mg 3 times daily for 7 days were similar in healthy geriatric adults 65-78 years of age and healthy younger adults 20-39 years of age; however, the mean elimination half-life was 24 hours in the geriatric individuals compared with 20 hours in the younger adults.
In children 1-12 years of age, the plasma elimination half-life of quinine reportedly averages 11-12 hours in those with malaria and 6 hours in those convalescing from the disease.
At toxic levels elimination half life is reported to be 26.5 + or - 5.8 hrs.

Toxicity Summary
IDENTIFICATION AND USE: Quinine is a bulky, white, amorphous powder or crystalline alkaloid, used as medication: non-narcotic analgesics; antimalarial; central muscle relaxants. It is also used as flavor in carbonated beverages. HUMAN EXPOSURE AND TOXICITY: Serious hypersensitivity reactions, including anaphylactic shock, anaphylactoid reactions, urticaria, serious skin rashes, angioedema, facial edema, bronchospasm, and pruritus, have been reported with quinine. In addition, thrombocytopenia, hemolytic uremic syndrome/thrombotic thrombocytopenic purpura (HUS/TTP), immune thrombocytopenic purpura, blackwater fever, disseminated intravascular coagulation, leukopenia, neutropenia, granulomatous hepatitis, and acute interstitial nephritis have been reported and may also be due to hypersensitivity reactions to the drug. Potentially fatal cardiac arrhythmias, including torsades de pointes and ventricular fibrillation, have been reported rarely during quinine therapy. At least 1 case of fatal ventricular arrhythmia has been reported in a geriatric patient with preexisting prolonged QT interval treated with IV quinine sulfate for Plasmodium falciparum malaria. Visual impairment can range from blurred vision and defective color perception, to visual field constriction and permanent blindness. Cinchonism occurs in virtually all patients with quinine overdose. There have been a large number of case reports of malformations following quinine ingestion in human pregnancy. Many of these pregnancies involved large doses of quinine used as an abortifacient. The most frequently reported abnormality following quinine exposure during early pregnancy is hypoplasia of the auditory nerve with resultant deafness. Other major malformations involving most organ systems have been reported also. However, the Perinatal Collaborative Study reported no association between first trimester exposure to quinine and birth defects. In general, there has been no proven association between quinine at doses used for malarial prophylaxis and an increased risk of malformations. Third trimester exposure to quinine does not appear to adversely affect uterine contractility. However, an increase in insulin secretion associated with hypoglycemia has been reported. Therefore, monitoring of blood or serum glucose levels during quinine therapy is advisable. Although the United States Food and Drug Administration banned its use for nocturnal leg cramps due to lack of safety and efficacy, quinine is widely available in beverages including tonic water and bitter lemon. Numerous anecdotal reports suggest that products containing quinine may produce neurological complications, including confusion, altered mental status, seizures, and coma, particularly in older women. ANIMAL STUDIES: Rabbits given 20 to 100 mg quinine hydrochloride/kg intravenously or intramuscularly 3 times a week for 10 weeks have been reported to show no ophthalmoscopic or histologic abnormalities in the fundus or optic nerve, and /another study/ similarly found no abnormality in most rabbits injected intraperitoneally with 10 mg/kg/day for 21 to 27 days showed degeneration of rods and cones and vacuoles in the retinal ganglion cells. In animal developmental studies conducted in multiple animal species, pregnant animals received quinine by the subcutaneous or intramuscular route at dose levels similar to the maximum recommended human dose based on body surface area (BSA) comparisons. There were increases in fetal death in utero in rabbits at maternal doses = 100 mg/kg/day and in dogs at = 15 mg/kg/day cochlea at maternal doses of 200 mg/kg corresponding to a dose level of approximately 1.4 times the MRHD based on BSA comparison. There were no teratogenic findings in rats at maternal doses up to 300 mg/kg/day and in monkeys at doses up to 200 mg/kg/day corresponding to doses approximately 1 and 2 times the MRHD respectively based on BSA comparisons. Quinine produces testicular toxicity in mice at a single intraperitoneal dose of 300 mg/kg, and in rats at an intramuscular dose of 10 mg/kg/day, 5 days/week, for 8 weeks. The findings include atrophy or degeneration of the seminiferous tubules, decreased sperm count and motility, and decreased testosterone levels in the serum and testes. Genotoxicity studies of quinine were positive in the Ames bacterial mutation assay with metabolic activation and in the sister chromatid exchange assay in mice. The sex-linked recessive lethal test performed in Drosophila, the in vivo mouse micronucleus assay, and the chromosomal aberration assay in mice and Chinese hamsters were negative.
The theorized mechanism of action for quinine and related anti-malarial drugs is that these drugs are toxic to the malaria parasite. Specifically, the drugs interfere with the parasite's ability to break down and digest hemoglobin. Consequently, the parasite starves and/or builds up toxic levels of partially degraded hemoglobin in itself.

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Hepatotoxicity
There is little evidence that chronic quinine therapy is associated with elevations in serum enzymes, although it has not been carefully assessed. However, there have been several reports of acute hypersensitivity reactions to quinine that include hepatic involvement. The reactions usually arise after 1 to 2 weeks of therapy, but can appear within 24 hours of restarting quinine or with rechallenge. The clinical features are marked by fatigue, nausea, vomiting, diffuse muscle aches, arthralgias and high fever. Blood testing at an early stage shows increases in serum aminotransferase and alkaline phosphatase levels as well as mild jaundice, which can deepen for a few days even after stopping quinine. The pattern of serum enzymes elevations is typically cholestatic or mixed. Rash is uncommon and eosinophilia is not typical, despite the presence of other signs of hypersensitivity (fever, arthralgias). Autoantibodies are not typically found. Liver biopsies usually show mild injury and small epithelioid granulomas, as are typically found in many organs during systemic hypersensitivity reactions. A similar clinical signature of liver injury occurs with quinidine, an optical isomer of quinine that is used predominantly as an antiarrhythmic.
Likelihood score: B (highly likely cause of clinically apparent liver injury).

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Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
Because of the low levels of quinine in breastmilk, amounts ingested by the infant are small and would not be expected to cause any adverse effects in breastfed infants. The dosage in milk is far below those required to treat an infant for malaria. However, quinine should not be used in mothers with an infant who is glucose-6-phosphate dehydrogenase (G6PD) deficient. Even the relatively small amounts of quinine in tonic water ingested by the mother have caused hemolysis in G6PD-deficient infants.
◉ Effects in Breastfed Infants
Four breastfed infants of 3 mothers, 3 boys and 1 girl (one set of twins) developed severe hemolysis following maternal ingestion of beverages containing quinine (e.g., tonic water). All infants had low levels of G6PD and were jaundiced on admission. Cessation of breastfeeding and tonic water and phototherapy and/or transfusion resolved the jaundice. One of the infants who was severely jaundiced had abnormal brainstem automatized evoked potentials at discharge. At 4 months of age he had a slight decrease in reactivity and a profound bilateral deafness. The breastmilk of one of the mothers was qualitatively positive for quinine. The hemolysis was probably caused by quinine in breastmilk.
◉ Effects on Lactation and Breastmilk
Relevant published information was not found as of the revision date.

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Protein Binding
Approximately 70%

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Interactions
Cinchona alkaloids, including quinine, may depress the hepatic synthesis of vitamin K-dependent coagulation factors, and the resulting hypoprothrombinemic effect may enhance the action of warfarin and other oral anticoagulants. In patients receiving these anticoagulants and concomitant therapy with quinine, the prothrombin time (PT), partial thromboplastin time (PTT), or international normalized ratio (INR) should be closely monitored as indicated.
The pharmacokinetics of quinine was investigated in patients with acute Falciparum malaria treated with quinine alone or in the presence of doxycycline. Twenty six patients divided into two groups of equal number were enrolled in the study. In the absence of doxycycline, the volume of distribution of quinine (mean + or - standard deviation) was estimated to be 1.32 + or - 0.32 l/kg, and its clearance was 0.125 + or - 0.47 l/hr/kg, which was only in partial agreement with previously published data. No effect of doxycycline on the pharmacokinetics of quinine was observed.
Quinine is a substrate for and an inhibitor of P-glycoprotein, and has the potential to affect the transport of drugs that are P-glycoprotein substrates.
Quinine may affect the pharmacokinetics of drugs that are CYP2D6 substrates. There is evidence that quinine decreased the metabolism of desipramine (a CYP2D6 substrate) in patients who were extensive CYP2D6 metabolizers, but had no effect in patients who were poor CYP2D6 metabolizers. Although low doses of quinine (80-400 mg) did not significantly affect the pharmacokinetics of some other CYP2D6 substrates (debrisoquine, dextromethorphan, methoxyphenamine), it is possible that higher quinine doses (600 mg or more) may inhibit the metabolism of these and other CYP2D6 substrates (e.g., flecainide, metoprolol, paroxetine). Patients receiving quinine concomitantly with drugs that are CYP2D6 substrates should be monitored closely for adverse effects of these drugs.
For more Interactions (Complete) data for QUININE (24 total), please visit the HSDB record page.

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Non-Human Toxicity Values
LD50 Guinea pig oral 1800 mg/kg
LD50 Mouse ip 115 mg/kg

[1]. Chemoprevention of DMBA induced skin carcinogenesis in swiss albino mice by quinine sulfate.(2016): 2636-2640.

[2]. Drug repurposing of quinine as antiviral against dengue virus infection. Virus Res. 2018 Aug 15;255:171-178. doi: 10.1016/j.virusres.2018.07.018. Epub 2018 Jul 25.

[3]. Quercetin protects against testicular toxicity induced by chronic administration of therapeutic dose of quinine sulfate in rats. J Basic Clin Physiol Pharmacol. 2012 Feb 27;23(1):39-44.

[4]. Quinine, an Old Anti-Malarial Drug in a Modern World: Role in the Treatment of Malaria. Malar J. 2011 May 24;10:144.

[5]. Mechanism of inhibition of mouse Slo3 (KCa 5.1) potassium channels by quinine, quinidine and barium. Br J Pharmacol. 2015 Sep;172(17):4355-63.

Therapeutic Uses
Analgesics, Non-Narcotic; Antimalarials; Muscle Relaxants, Central
Qualaquin (quinine sulfate) is an antimalarial drug indicated only for treatment of uncomplicated Plasmodium falciparum malaria. Quinine sulfate has been shown to be effective in geographical regions where resistance to chloroquine has been documented. /Included in US product label/
Oral quinine sulfate is used in conjunction with IV or oral clindamycin for the treatment of babesiosis caused by Babesia microti. /NOT included in US product label/
Although quinine sulfate is not approved by the FDA for the treatment of severe or complicated malaria, the CDC states that oral quinine sulfate can be used in conjunction with doxycycline, tetracycline, or clindamycin for follow-up treatment after an appropriate initial parenteral regimen.
For more Therapeutic Uses (Complete) data for QUININE (8 total), please visit the HSDB record page.

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Drug Warnings
/BOXED WARNING/ WARNING: Qualaquin use for the treatment or prevention of nocturnal leg cramps may result in 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. The risk associated with Qualaquin use in the absence of evidence of its effectiveness in the treatment or prevention of nocturnal leg cramps outweighs any potential benefit.
Serious hypersensitivity reactions, including anaphylactic shock, anaphylactoid reactions, urticaria, serious skin rashes (e.g., Stevens-Johnson syndrome, toxic epidermal necrolysis), angioedema, facial edema, bronchospasm, and pruritus, have been reported with quinine. In addition, thrombocytopenia, hemolytic uremic syndrome/thrombotic thrombocytopenic purpura (HUS/TTP), immune thrombocytopenic purpura, blackwater fever, disseminated intravascular coagulation, leukopenia, neutropenia, granulomatous hepatitis, and acute interstitial nephritis have been reported and may also be due to hypersensitivity reactions to the drug.
Potentially fatal cardiac arrhythmias, including torsades de pointes and ventricular fibrillation, have been reported rarely during quinine therapy. At least 1 case of fatal ventricular arrhythmia has been reported in a geriatric patient with preexisting prolonged QT interval treated with IV quinine sulfate for Plasmodium falciparum malaria.
Serious, life-threatening, and sometimes fatal hematologic reactions, including thrombocytopenia and thrombocytopenia, hemolytic uremic syndrome/thrombotic thrombocytopenic purpura (HUS/TTP), have been reported in patients receiving quinine, especially patients using the drug for unlabeled indications (prevention or treatment of leg cramps or restless leg syndrome). Subsequent development of chronic renal impairment has occurred in patients with quinine-associated TTP.
For more Drug Warnings (Complete) data for QUININE (37 total), please visit the HSDB record page.

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Pharmacodynamics
Quinine is used parenterally to treat life-threatening infections caused by chloroquine-resistant Plasmodium falciparum malaria. Quinine acts as a blood schizonticide although it also has gametocytocidal activity against P. vivax and P. malariae. Because it is a weak base, it is concentrated in the food vacuoles of P. falciparum. It is thought to act by inhibiting heme polymerase, thereby allowing accumulation of its cytotoxic substrate, heme. As a schizonticidal drug, it is less effective and more toxic than chloroquine. However, it has a special place in the management of severe falciparum malaria in areas with known resistance to chloroquine.

C20H24N2O2EXACTMASS

324.42

324.183

130-95-0

Quinine hydrochloride dihydrate;6119-47-7;Quinine sulfate hydrate;6119-70-6;Quinine hemisulfate;804-63-7;Quinine sulfate;549-56-4;Quinine hydrobromide;549-49-5;Quinine dihydrochloride;60-93-5;Quinine hemisulfate hydrate;207671-44-1

3034034

White to off-white solid powder

1.2±0.1 g/cm3

495.9±40.0 °C at 760 mmHg

176-177ºC

253.7±27.3 °C

0.0±1.3 mmHg at 25°C

1.638

3.44

1

4

4

24

457

4

COC1=CC2=C(C=CN=C2C=C1)[C@H]([C@@H]3C[C@@H]4CCN3C[C@@H]4C=C)O

LOUPRKONTZGTKE-UHFFFAOYSA-N

InChI=1S/C20H24N2O2/c1-3-13-12-22-9-7-14(13)10-19(22)20(23)16-6-8-21-18-5-4-15(24-2)11-17(16)18/h3-6,8,11,13-14,19-20,23H,1,7,9-10,12H2,2H3

(R)-[(2S,4S,5R)-5-ethenyl-1-azabicyclo[2.2.2]octan-2-yl]-(6-methoxyquinolin-4-yl)methanol

Quinine Chinin Chininum 6'-Methoxycinchonidine (8S,9R)-Quinine Qualaquin Odan Brand of Quinine Sulfate Plough Brand of Quinine Sulfate Prosana Brand of Quinine Bisulfate Quinamm Quinbisan Quinbisul Quindan

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: (1). This product requires protection from light (avoid light exposure) during transportation and storage.  (2). Please store this product in a sealed and protected environment (e.g. under nitrogen), avoid exposure to moisture.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : ≥ 100 mg/mL (~308.24 mM)
H2O : ~0.1 mg/mL (~0.31 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (7.71 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (7.71 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (7.71 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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 (Please use freshly prepared in vivo formulations for optimal results.)