PIRE 2
RIFAMPICIN AND ISONIAZID · by GENIX
Composition
Susp/Syp 100/50 mg: Per 5 ml: Rifampicin 100 mg, isoniazid 50 mg. Powder: Isoniazid 30 mg, Rifampicin 60 mg; sachet. Cap/Tab 150/100 mg: Rifampicin 150 mg, isoniazid 100 mg. Cap/Tab 300/150 m
Indications & Dosage
Treatment of tuberculosis (continuation phase): Adult (body-weight up to 50 kg): 450/300 mg daily for 4 months (continuation phase after 2-month initial phase), preferably taken before breakfast. Adult (body-weight 50 kg and above): 600/300 mg dailyfor 4 months (continuation phase after 2-month initial phase), preferably takenbefore breakfast. Children: Up to 20 mg/kg daily calculated as rifampicin to be given as a single dose.
Contraindications
Previous hypersensitivity to any rifamycin, patients with previous isoniazid associated hepatic injury or other severe adverse reactions with isoniazid.
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, caution patients against intentional or accidental interruption of daily dosage regimen, since rare renal hypersensitivity reactions have been reported when therapy is resumed. Urine, faeces, saliva, sputum, sweat and tears may be coloured red-orange.
Interactions
Rifampicin induces hepatic microsomal enzymes that metabolize a wide variety of drugs e.g. metoprolol, propranolol, quinidine, corticosteroids, contraceptives; 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, haernoglobinuria, hematuria, menstrual disturbances, peripheral neuropathy, elevated SGOT, SGPT, SGOPT, agranulocytosis, fever, skin eruptions, pyridoxine deficiency.