COMPOSITION: Each tablet contains 300 mg Quinine Sulphate.
PHARMACOLOGICAL CLASSIFICATION: A 17.1 Peripherally acting muscle relaxants.
PHARMACOLOGICAL ACTION: Quinine is a highly active blood schizonticide and suppresses the asexual cycle of development of malaria parasites in the erythrocytes. It is effective both as a suppressive drug and in the overt clinical attack of malaria.
In addition quinine exerts relaxant effects on skeletal muscle. It increases the tension responses to a single maximal stimulus delivered to the muscle directly or through the nerve but it increases the refractory period of muscle so that the response to tetanic stimulation is reduced. Recumbency leg muscle cramps and myotonia congenita are thus effectively relieved by treatment with quinine.
INDICATIONS: Quinine sulphate tablets are indicated mainly in the resistant strains of plasmodium falciparum malaria. It is also indicated as a muscle relaxant in myotonia congenita and myotonic contraction as well as nocturnal muscle cramps. A secondary indication is its use in the diagnostic test for myasthenia gravis.
CONTRA-INDICATIONS: Quinine and its salts are contra-indicated in patients with a history of hypersensitivity to quinine and in patients with tinnitus or optic neuritis and especially when this takes the form of cutaneous, angioedematous, visual, or auditory symptoms. Quinine should be discontinued immediately if evidence of haemolysis appears. Pregnancy in a patient with malaria is not generally regarded as a contra-indication 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. Quinine should be avoided in patients with myasthenia gravis, as it may aggravate their condition.
Use of Mefloquine with quinine sulphate may increase the chance of side-effects.
Use with Mefloquine: Concurrent use with quinine may result in an increased incidence of seizures and of electrocardiogram abnormalities, predisposing the patient to arrhythmias, it is recommended that Mefloquine be administered at least 12 hours after the last dose of quinine. Patients taking weekly mefloquine prophylaxis may be found to have mefloquine-resistant malaria that requires treatment with quinine, because mefloquine has a very long half-life (approximately 20 days) it will remain in the body long after the drug has been discontinued. Although there is insufficient information available, it is recommended that if quinine must be given that the patient be hospitalized, if possible, and monitored for QT prolongation and possible rhythm disturbances. Seizure activity may also be potentiated in these patients. In patients considered to be at high risk for a seizure, additional precautions and interventions may be indicated.
DOSAGE AND DIRECTIONS FOR USE:
Adults: 300 mg to 600 mg given at night for nocturnal cramps. Treatment is discontinued after several cramp-free nights. S4: For the treatment of Falciparum Malaria a course usually lasts 7 days. Treatment is usually given orally. Adults: 600 mg every eight hours for 7 days Children: 10 mg per kg body-weight every 8 hours for 7 days.
In severe or complicated falciparum malaria or when the patient is unable to take oral medication, quinine should be given parenterally, preferably by slow intravenous infusion, but this can be hazardous and patients generally need monitoring for signs of cardiotoxicity.
SIDE-EFFECTS AND SPECIAL PRECAUTIONS: Administration of quinine in usual therapeutic doses may give rise to a train of symptoms known as cinchonism, characterised by tinnitus, impaired hearing, headache, nausea and disturbed vision in its mild form, with in addition vomiting, abdominal pain, diarrhoea and vertigo, in its more severe manifestations, rashes frequently appear. Visual disturbances consist of blurred vision, disturbed colour perception, photophobia, diplopia, night blindness, constricted visual fields, scotoma, mydriasis, and, very rarely, even blindness.
Cinchonism may also occur after small doses in patients hypersensitive to quinine, but urticaria and flushing of the skin with intense pruritus are the most frequent reactions seen inthese patients, other effects include fever, skin rashes and dyspnoea. Angioedema especially of the face may also occur and asthma can be precipitated. Thrombocytopenic purpura has been associated with quinine hypersensitivity. Haemoglobinuria occurs rarely. Other adverse effects of quinine may include hypoprothrombinaemia and agranulocytosis. Quinine should be used with caution in patients with atrial fibrillation or other serious heart disease. Quinine may also cause haemolysis in some types of glucose-6-phosphate dehydrogenase deficiency and should be used with care.
Hypoglycaemia is now recognised to be a frequent complication encountered in falciparum malaria, it is important to recognise that hypoglycaemia may be the cause of coma rather than cerebral malaria and that hypoglycaemia may also be induced by antimalarial therapy.
KNOWN SYMPTOMS OF OVERDOSAGE AND PARTICULARS OF ITS TREATMENT: Main symptoms of overdosage, which can be fatal, include gastro-intestinal effects, oculotoxicity, central nervous system disturbances, and cardiotoxicity. Visual disturbances including sudden blindness are usually slowly reversible but there may be residual damage. Quinine can produce cardiovascular toxicity similar to that seen with quinidine including conduction disturbances, dysrhythmias, anginal symptoms and hypotension leading to cardiac arrest and circulatory failure. In acute overdosage with quinine, the stomach should be emptied by lavage if ingestion has been recent. Oral administration of activated charcoal may also be of some benefit. Treatment is mostly symptomatic with attention being given to maintaining blood pressure, respiration and renal function and to treating arrhythmias. Central nervous system symptoms are noted in more severe grades of poisoning, particularly noted are: headache, fever, vomiting, apprehension, excitement, confusion, delirium, and syncope. Respiration is first stimulated and is then shallow and depressed. The skin becomes cold and cyanotic as poisoning progresses, the body temperature and the blood pressure fall, weakness is extreme, the pulse is feeble, coma ensues, and death occurs from respiratory arrest.
IDENTIFICATION: White, biconvex tablets.
PRESENTATION: Plastic containers of 100 and 1000 tablets.
STORAGE INSTRUCTIONS: Store below 25°C in airtight containers.
Protect from light and moisture. KEEP OUT OF REACH OF CHILDREN.
REFERENCE NUMBER: H967 (Act 101/1965)
NAME AND BUSINESS ADDRESS OF APPLICANT: Pharmacare Limited
DATE OF PUBLICATION OF THIS PACKAGE INSERT: 6.12.74
A & S PRINTERS
Updated on this site: April 2005
Source: Hospital Pharmacy