4.1. Therapeutic indications

For the treatment of chloroquine resistant falciparum malaria in adults and children aged 5 years or older (and ≥ 20kg)

Treatment and prevention of nocturnal leg cramps in adults and the elderly, when cramps cause regular disruption of sleep (see section 4.2 and Section 4.4).

4.2. Posology and method of administration

Posology

Treatment of falciparum (malignant tertian) malaria:

Adults (including the elderly) and children aged 12 years and over: 600mg of quinine sulfate given every 8 hours for 7 days. The dose may depend upon the size of the patient, severity of infection, and evidence of renal or liver disease (when the intervals should be increased), due to a prolonged half-life of the drug.

Note

If quinine resistance is known or suspected on completion of the course, additional treatment may be given. This may be one of the following:

1. doxycycline 200mg daily (as a single dose or in 2 divided doses) for at least 7 days.

2. clindamycin 300mg four times daily for 5 days.

If part or all of the dose is vomited within 1 hour of administration, then the same amount must be administered immediately.

Children aged 11 years and under: 10mg/kg every eight hours for 7 days.

For the treatment and prevention of nocturnal leg cramps

Adults (including the elderly):

The recommended dose is 200mg at bedtime. The maximum dose is 300mg.

A reduction in frequency of leg cramps may take up to 4 weeks to become apparent. Patients should be monitored closely during the early stages of treatment for adverse effects. After an initial trial of 4 weeks, treatment should be stopped if there is no benefit. Treatment should be interrupted at approximately three monthly intervals to assess the need for continuation of treatment with quinine.

Paediatric population

Treatment of chloroquine resistant falciparum malaria

The dosage regimen for children by mouth is 10mg of quinine sulfate per kg body weight given every 8 hours for 7 days. Quinine sulfate 200mg tablets are not suitable for children weighing less than 20kg or less than 5 years old.

Method of administration

For oral administration.

4.3. Contraindications

- Hypersensitivity to the active substance or to any of the excipients listed in section 6.1

- Tinnitus

- Optic neuritis

- Haemolysis or Haemoglobinuria

- Myasthenia gravis (quinine may cause severe respiratory distress and dysphagia in these patients)

- As quinine has been implicated in precipitating blackwater fever, it is generally contraindicated in patients who have already suffered an attack.

4.4. Special warnings and precautions for use

Cinchonism

Administration of quinine may give rise to cinchonism, which is generally more severe in overdose, but may also occur in normal therapeutic doses. Patients should be warned not to exceed the prescribed dose, because of the possibility of serious, irreversible side effects in overdose. Treatment for night cramps should be stopped if symptoms of cinchonism emerge. Such symptoms include tinnitus, impaired hearing, headache, nausea, and disturbed vision (see sections 4.8 and 4.9).

Hypersensitivity

Hypersensitivity to quinine may also occur with symptoms of cinchonism together with urticaria, flushing, pruritus, rash, fever, angioedema, dyspnoea and asthma.

Serious hypersensitivity reactions including Stevens-Johnson syndrome have been reported with quinine.

Cardiac disorders

Quinine should be used with caution in patients with atrial fibrillation, other cardiac conduction defects and heart block or other serious heart disease. It may cause hypoprothrombinaemia and enhance the effects of anticoagulants.

Quinine has dose-dependent QT-prolonging effects. Caution is recommended in patients with conditions which predispose to QT-prolongation and in patients with atrioventricular block.

Glucose-6-Phosphate Dehydrogenase (G-6-PD) Deficiency

Quinine has been implicated in precipitating blackwater fever when given for prolonged periods, although, in some cases deficiency of glucose-6-phosphate dehydrogenase may have been involved. Patients with glucose-6-phosphate dehydrogenase deficiency may be at increased risk of haemolysis during quinine therapy and may develop acute haemolytic anaemia.

Quinine should not be withheld from pregnant women who have life threatening malaria (see section 4.6).

Treatment with quinine should be monitored in all patients in case signs of resistance develop.

Use for nocturnal leg cramps

Before use for nocturnal leg cramps, the risks, which include significant adverse effects and interactions (see sections 4.5 and 4.8), should be carefully considered relative to the potential benefits. These risks are likely to be of particular concern in the elderly. Quinine should only be considered when cramps are very painful or frequent, when other treatable causes of cramp have been ruled out, and when non-pharmacological measures have not worked. Quinine sulfate should not be used for this indication during pregnancy (see section 4.6).

Thrombocytopenia

Quinine may cause unpredictable serious and life-threatening thrombocytopenia, which is thought to be an idiosyncratic hypersensitivity reaction. Quinine should not be prescribed or administered to patients who have previously experienced any adverse reaction to quinine, including that in tonic water or other beverages. Patients should be instructed to stop treatment and consult a physician if signs of thrombocytopenia such as unexplained bruising or bleeding occur.

Reduce the dosage (or increase intervals between doses) in renal or hepatic disease.

Patients with rare hereditary problems of galactose intolerance, total lactase deficiency or glucose-galactose malabsorption should not take this medicine, as it contains lactose.

This medicine contains less than 1 mmol sodium (23 mg) per tablet, i.e. is essentially 'sodium-free'

4.5. Interaction with other medicinal products and other forms of interaction

Effect of other drugs on quinine

CYP3A4 substrate

Quinine is metabolised via hepatic oxidative cytochrome P450 pathways, predominantly by CYP3A4. There is the potential for increased quinine toxicity with concurrent use of potent CYP3A4 inhibitors, which include azole antifungal drugs and HIV protease inhibitors.

Sub-optimal quinine serum levels may result from concomitant use of CYP3A4 inducers such as rifampicin, barbiturates, carbamazepine and phenytoin.

Care should be taken when quinine is used in combination with other CYP3A4 substrates, especially those causing prolongation of the QT interval.

Effect of quinine on other drugs

The plasma concentration of flecanide, digoxin and mefloquine may be increased.

Amantadine: Quinine can reduce the renal clearance of amantadine with risk of amantadine toxicity (including headache, nausea, dizziness).

Analgesics: increased risk of ventricular arrhythmias with levacetylmethadol (avoid concomitant use).

If quinine is administered the maintenance dose of digoxin should be halved.

Ciclosporin: Quinine can decrease serum plasma concentrations of ciclosporin

Cardiac glycosides: Quinine increases plasma concentrations of cardiac glycosides and reduced dosage of concomitant cardiac glycosides such as digoxin to half the maintenance dose may be necessary. Quinine has been reported to increase serum digoxin concentrations and quinine has reduced total body clearance of digoxin.

Other drug interactions

Drug caused QT prolongation

There is an increased risk of ventricular arrhythmias when quinine is given in combination with other drugs that prolong the QT interval, including amiodarone, moxifloxacin, pimozide, thioridazine, terfenadine and halofantrine and therefore concomitant use with these products should be avoided.

Antiarrhythmics: Concomitant use of amiodarone should be avoided due to the increased risk of ventricular arrhythmias. The plasma concentration of flecainide is increased by quinine. Concomitant use of quinidine may increase the possibility of cinchonism.

Antibacterials: There is an increased risk of ventricular arrhythmias when moxifloxacin is given with quinine. Rifampicin can reduce the serum levels of quinine, therefore reducing its therapeutic effect.

Anticoagulants: Quinine may cause hypoprothrombinaemia and enhance the effects of anticoagulants. In one report, reductions in warfarin dosage were necessary after ingestion of large amount of tonic water containing quinine. Caution is advised when administering quinine with drugs which could prolong the QT interval

Antihistamines: Concomitant use of astemizole and terfenadine should be avoided due to the increased risk of ventricular arrhythmias.

Antimalarials: According to the manufacturer of artemether with lumefantrine concomitant use should be avoided. There is an increased risk of side effects if quinine is used with other antimalarials, for example, chloroquine, halofantrine and mefloquine (increased risk of convulsion), although this should not prevent their use in severe cases. Chloroquine and quinine appear to be antagonistic when given together for P falciparum malaria. There is a decrease in plasma concentrations of primaquine.

There is an increased risk of inducing ventricular arrhythmias if quinine is given with halofantrine.

Antipsychotics: There is an increased risk of ventricular arrhythmias and concomitant use should be avoided with pimozide or thioridazine.

Hypoglycaemics: Concurrent use with oral hypoglycaemics may increase the risk of hypoglycaemia.

Suxamethonium: Quinine enhances the neuromuscular effects of suxamethonium.

Ulcer-healing drugs: Cimetidine inhibits quinine metabolism leading to increased plasma-quinine concentrations.

Anti-epileptics: Quinine may increase the levels of phenobarbital and of carbamazepine. Patients should be monitored closely during concomitant use of quinine with these agents.

4.6. Fertility, pregnancy and lactation

Pregnancy

Large doses of quinine can induce abortion. Quinine may cause congenital abnormalities of the CNS and extremities. Following administration of large doses during pregnancy, phototoxicity and deafness have been reported in neonates. Quinine sulfate should not be used during pregnancy unless the benefits outweigh the risks.

Treatment of falciparium malaria: Pregnancy in a patient with malaria is not generally regarded as a contraindication to the use of quinine. As malaria infection is potentially serious during pregnancy and poses a threat to the mother and foetus, there appears to be little justification in withholding treatment in the absence of a suitable alternative.

Prophylaxis of nocturnal leg-cramps: Quinine sulfate should not be used during pregnancy to treat cramps.

Breast-feeding

Quinine sulfate is excreted in breast milk, but no problems in humans have been reported. Infants at risk for glucose-6-phosphate dehydrogenase deficiency should not be breast-fed until the disease can be ruled out. However, quinine sulfate should not be given to nursing mothers unless the benefits outweigh the risks.

Fertility

The effects of quinine on fertility are unknown.

4.7. Effects on ability to drive and use machines

Quinine may cause visual disturbances and vertigo, hence patients should be advised that if affected they should not drive or operate machinery

4.8. Undesirable effects

Adverse drug reactions are ranked by frequency, the most frequent first, using the following convention: very common (≥ 1/10); common (≥ 1/100 to < 1/10); uncommon (≥ 1/1,000 to < 1/100); rare (≥ 1/10,000 to < 1/1,000); very rare (< 1/10,000), not known (cannot be estimated from the available data).

MedDRA system organ class

Adverse Reaction

Frequency

Not Known

Blood and lymphatic system disorders

Thrombocytopenia, intravascular coagulation, hypoprothrombinaemia, haemoglobinuria, oliguria, haemolytic uraemic syndrome, pancytopenia, haemolysis, agranulocytosis, thrombocytopenic purpura.

Immune system disorders

Eczematous dermatitis, oedema, erythema,lichen planus,hypersensitivity reactions such as asthma, angioneurotic oedema, photosensitivity, hot and flushed skin, fever, pruritus, thrombocytopenic purpura and urticaria.

Metabolism and nutritional disorders

Hypoglycaemia

Psychiatric disorders

Agitation and confusion.

Nervous system disorders

Headache, vertigo, excitement, loss of consciousness, coma and death.

Eye disorders

Blurred vision, defective colour perception, visual field constriction, total blindness.

Ear and labyrinth disorders

Tinnitus, impaired hearing.

Cardiac disorders

Atrioventricular conduction disturbances, a fall in blood pressure coupled with a feeble pulse, prolongation of the QT interval, widening of the QRS complex and T wave flattening.

Respiratory, thoracic and mediastinal disorders

Bronchospasm, dyspnoea, asthma may occur

Gastrointestinal Disorders

Nausea, vomiting, diarrhoea, abdominal pain*, fever may occur after long term administration of quinine.

Skin and subcutaneous tissue disorders

Flushing, rash, urticaria, eczematous dermatitis, oedema, erythema, lichen planus, pruritus, photosensitivity, Stevens-Johnson syndrome.

Musculoskeletal and connective tissue disorders

Muscle weakness, aggravation of myasthenia gravis.

Renal and urinary disorders

Renal insufficiency, acute renal failure (may be due to an immune mechanism or circulatory failure.), oliguria.

Reproductive system and breast disorders

Abortion**.

General disorders and administration site conditions

Fever, Cinchonism***

* May occur after long term administration of quinine.

** Toxic doses of quinine may induce abortion, but it is unwise to withhold the drug if less toxic antimalarials are not available.

*** More common in overdose but may occur even after normal doses of quinine. In its mild form symptoms include tinnitus, impaired hearing, rashes, headache, nausea and disturbed vision. Its more severe manifestations symptoms may include gastrointestinal symptoms, oculotoxicity, CNS disturbances, cardiotoxicity and death (see section 4.9). Visual disorders (blurred vision, defective colour perception, visual field constriction and total blindness).

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme; website: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.

4.9. Overdose

Acute intoxication can be seen after ingestion of doses of 4-12g, but a dose of 8g can prove lethal. The average fatal dose for an adult is about 8g although deaths have been reported from as little as 1.5g in an adult and 900mg in a child.

Symptoms:

Quinine overdosage may lead to serious side effects including irreversible visual loss and can be fatal.

Symptoms include nausea, vomiting, tinnitus, deafness, headache vasodilation and disturbed vision.

Features of a significant overdose include convulsions, impairment of consciousness, coma, respiratory depression, QT prolongation, ventricular arrhythmia, cardiogenic shock and renal failure.. High doses of quinine are teratogenic and may cause miscarriage. Hypokalaemia and hypoglycaemia may also occur.

Treatment

Children (< 5 years) who have ingested any amount should be referred to hospital.

Older children and adults should be referred to hospital if more than 30mg/kg of quinine base has been taken.

Note:

Each quinine sulfate 200mg tablet is equivalent to 165mg of quinine base.

Quinine is rapidly absorbed. Consider activated charcoal (50g for adults; 1g/kg for children) if the patient presents within 1 hour of ingestion of more than 30mg/kg quinine base or any amount in a child under 5 years. Multiple dose activated charcoal will enhance quinine elimination.

Observe patients for at least 12 hours after ingestion. Monitor cardiac conduction and rhythm, serum electrolytes, blood glucose and visual acuity.

Other treatment is symptomatic to maintain blood pressure, respiration, renal function and to treat arrhythmia, convulsions, hypoglycaemia and acidosis.