BNF for Children 2011-2012

492 9.8.1 Drugs used in metabolic disorders BNFC 2011–2012Indication and doseMucopolysaccharidosis VI (specialist use only). By intravenous infusionChild 5–18 years 1 mg/kg once weeklyAdministration for intravenous infusion, dilute requisitedose with Sodium Chloride 0.9% to a final volumeof 250 mL and mix gently; infuse through a 0.2 micronin-line filter; give approx. 2.5% of the total volumeover 1 hour, then infuse remaining volume over next 3hours; if body-weight under 20 kg and at risk of fluidoverload, dilute requisite dose in 100 mL SodiumChloride 0.9% and give over at least 4 hoursNaglazyme c (BioMarin) TAConcentrate for intravenous infusion, galsulfase1 mg/mL, net price 5-mL vial = £982.00Indication and doseNon-neurological manifestations of mucopolysaccharidosisI (specialist use only). By intravenous infusionChild 1 month–18 years 100 units/kg onceweeklyAdministration for intravenous infusion, dilute withSodium Chloride 0.9%; body-weight under 20 kg,dilute to 100 mL, body-weight over 20 kg dilute to250 mL; give through in-line filter (0.22 micron) initiallyat a rate of 2 units/kg/hour then increase graduallyevery 15 minutes to max. 43 units/kg/hourAldurazyme (Genzyme) AConcentrate for intravenous infusion, laronidase100 units/mL, net price 5-mL vial = £444.70Electrolytes Na + 1.29 mmol /5-mL vial9 Nutrition and bloodIDURSULFASECautions severe respiratory disease; acute febrilerespiratory illness (consider delaying treatment)Infusion-related reactions See notes aboveContra-indications women of child-bearing potentialPregnancy manufacturer advises avoidBreast-feeding manufacturer advises avoid—presentin milk in animal studiesSide-effects gastro-intestinal disturbances, swollentongue; arrhythmia, tachycardia, chest pain, cyanosis,peripheral oedema, hypertension, hypotension,flushing; bronchospasm, hypoxia, cough, wheezing,tachypnoea, dyspnoea; headache, dizziness, tremor;pyrexia; arthralgia; facial oedema, urticaria, pruritus,rash, infusion-site swelling, erythema; pulmonaryembolism and anaphylaxis also reportedIndication and doseMucopolysaccharidosis II (specialist use only). By intravenous infusionChild 5–18 years 500 micrograms/kg onceweeklyAdministration for intravenous infusion, dilute requisitedose in 100 mL Sodium Chloride 0.9% and mixgently (do not shake); give over 3 hours (graduallyreduced to 1 hour if no infusion-related reactions)Elaprase c (Shire HGT) TAConcentrate for intravenous infusion, idursulfase2 mg/mL, net price 3-mL vial = £1985.00LARONIDASECautions monitor immunoglobulin G (IgG) antibodyconcentration; interactions: Appendix 1 (laronidase)Infusion-related reactions See notes abovePregnancy manufacturer advises avoid unless essential—noinformation availableBreast-feeding manufacturer advises avoid—noinformation availableSide-effects nausea, vomiting, diarrhoea, abdominalpain; cold extremities, pallor, flushing, tachycardia,blood pressure changes; dyspnoea, cough, angioedema,anaphylaxis; headache, paraesthesia, dizziness,fatigue, restlessness; influenza-like symptoms;musculoskeletal pain, pain in extremities; rash, pruritus,urticaria, alopecia, infusion-site reactions;bronchospasm and respiratory arrest also reportedNephropathic cystinosisMercaptamine is available for the treatment of nephropathiccystinosis. The oral dose is increased over severalweeks to avoid intolerance. Mercaptamine has avery unpleasant taste and smell, which can affect compliance.All patients receiving mercaptamine should be registered(contact local specialist centre for details).Mercaptamine eye drops are used in the management ofocular symptoms arising from the deposition of cystinecrystals in the eye.Safe PracticeMercaptamine has been confused with mercaptopurine;care must be taken to ensure the correctdrug is prescribed and dispensed.MERCAPTAMINE(Cysteamine)Cautions leucocyte-cystine concentration and haematologicalmonitoring required—consult productliterature; dose of phosphate supplement may need tobe adjusted if transferring from phosphocysteamine tomercaptamineContra-indications hypersensitivity to penicillaminePregnancy avoid—teratogenic and toxic in animalstudiesBreast-feeding avoidSide-effects breath and body odour, nausea, vomiting,diarrhoea, anorexia, abdominal pain, gastroenteritis,dyspepsia, encephalopathy, headache, malaise,fever, rash; less commonly gastro-intestinal ulcer,seizures, hallucinations, nervousness, leucopenia,nephrotic syndromeLicensed use eye drops not licensedIndication and doseNephropathic cystinosis (specialist use only). By mouthNeonate initially one-sixth to one-quarter of theexpected maintenance dose, increased graduallyover 4–6 weeks; maintenance, 1.3 g/m 2 (approx.50 mg/kg) daily in 4 divided doses