Composition: Human hemin 25mg/ml.
Presentation: Concentrate for solution for infusion.
Storage and stability: Store between 2-8C, protected from light. The diluted solution should be used immediately.
Action: Hemin suppresses the activity of delta-amino-laevulinic synthase.
Indications: Treatment of acute attacks of hepatic porphyria (acute intermittent porphyria, porphyria variegata, hereditary coproporphyria).
Contraindications: Known hypersensitivity to one of the constituents of Normosang.
Dosage and administration: Adults and elderly, recommended daily dose 3mg/kg once daily for four days, diluted in 100ml of 0.9 per cent sodium chloride in a glass bottle and infused intraveneously over at least 30 minutes into a large brachial vein using an inline filter. The dose should not exceed 250mg (one ampoule) daily. Exceptionally, the course may be repeated under strict biochemical surveillance if there is inadequate response after the first course of treatment.
Children, limited experience in tyrosinaemia suggests that it is safe to use a dose of not more than 3mg/kg daily for four days, administered with the same precautions as for adults. See SPC for preparation and administration of solution.
Overdosage: In animal experiments, acute toxic effects after high dosage, were directed to the liver. Ten times higher total doses than the recommended human posology also decreased blood pressure in rats. Higher doses may also cause disturbances in hemostasis. Propylene glycol (4000mg/10ml in Normosang) in high doses may cause central nervous system side effects, lactic acidosis, kidney and liver toxicity, increase in plasma osmolarity and haemolytic reactions. See SPC for therapeutic measures.
Precautions: Before treatment is started, an attack of hepatic porphyria must be confirmed by a series of clinical and biological criteria (see SPC). Patients should be warned of the risk of attacks being worsened or triggered by fasting or taking certain medicinal products, particularly oestrogens, barbiturates and steroids. See SPC for details on limiting the risk for transmission of infective agents. Only prescribe in pregnancy and lactation when absolutely necessary.
Drug interactions: During treatment with hemin the activity of cytochrome P450 enzymes increases. The metabolism of concomitantly administered drugs that are metabolised by cytochrome P450 enzymes may increase, leading to lower systemic exposure.
Side effects: Pain may be caused if the infusion is administered into veins that are too small. Cases of thrombophlebitis have been reported. Rarely, fever and allergic reactions.
Net price: 4 x 10ml ampoules £1,125.
Supplier: Orphan Europe (UK) Ltd, 32 Bell Street, Henley-on-Thames, Oxfordshire RG9 2BH. Tel 01491 414333, fax 01491 414443.
Legal class: POM.