MYRIN
RIFAMPICIN, ISONIAZID AND ETHAMBUTOL · by PFIZER
Composition
Tab 150/75/275 mg: Rifampioin 150 mg, isoniazid/5mg, ethambutol 275 mg. Tab 150/75/300 mg: Rifampicin 150 mg, isoniazid 75 mg. ethambutol 300 mg. Tab 150/75/350 mg: Rifampicin 150 mg. isoniaz
Indications & Dosage
Treatment of tuberculosis: Adults & Children:1 tab/15 kg body-weight daily one or two hr before a meal.
Contraindications
Previous hypersensitivity to any rifamycin, patients with previous isoniazid associated hepatic injury or other severe adverse reactions with isoniazid, hypersensitivity to ethambutol, optic neuritis
Precautions
Patients with active chronic liver disease or severe renal dysfunction. Isoniazid crosses the placental barrier and passes into maternal breast milk, observe neonates, breast fed infants of isoniazid treated mothers for any evidence of adverse effects. Reduce dosage in patients with decreased renal functions. Caution patients against intentional or accidental interruption of daily dosage regimen; renal hypersensitivity reactions have been reported when therapy is resumed. Urine, faeces, saliva, sputum, sweat and tears may be coloured red-orange.
Interactions
The effectiveness may be decreased when taking concomitantly with aluminium salts. Rifampicin induces hepatic microsomal enzymes that metabolize a wide variety of drugs e.g. metoprolol, propranolol, quinidine, corticosteroids, contra-ceptives, oral anticoagulants, oral sulfonylureas. The effectiveness of isoniazid may be decreased when administered with corticosteroid. The effects of benzodiazepines may be increased. The hepatic toxicity of both isoniazid and/or rifampicin may be increased when administered concomitantly.
Pregnancy
Caution advised, use only if potential benefit outweighs risk
Lactation
Caution advised
Side Effects
Anaphylactoid reactions, heartburn, epigastric dis-tress, anorexia, nausea, vomiting, diarrhoea, sore mouth, rash, pruritus, urticaria, eosinophilia, thrombocytopenia, muscular weakness, pain in extremities, visual disturbances, haemoglobinuria, hematuria, menstrual disturbances, peripheral neuropathy, elevated SOOT, SGPT, SGOPT, agranulocytosis, fever, skin eruptions, pyridoxine deficiency, optic neuritis, malaise headache diz-ziness, elevated serum uric acid level.