BNF for Children 2011-2012

368 6.2.2 Antithyroid drugs BNFC 2011–20126 Endocrine systemBreast-feeding amount in milk may be sufficient toaffect neonatal thyroid function, therefore lowesteffective dose should be used; see notes aboveSide-effects nausea, mild gastro-intestinal disturbances,taste disturbance, hepatic disorders (includinghepatitis and jaundice), headache, fever, malaise, rash,pruritus, arthralgia; rarely myopathy, alopecia, bonemarrow suppression (including pancytopenia andagranulocytosis, see Neutropenia and Agranulocytosisabove), hypersensitivity reactionsIndication and doseHyperthyroidism (including Graves’ disease). By mouthNeonate initially 750 micrograms/kg daily in singleor divided doses until euthyroid then adjust asnecessary (see notes above); higher initial doses(up to 1 mg/kg daily) are occasionally required,particularly in thyrotoxic crisisChild 1 month–12 years initially 750 micrograms/kg(max. 30 mg) daily in single or divideddoses until euthyroid then adjusted as necessary(see notes above); higher initial doses occasionallyrequired, particularly in thyrotoxic crisisChild 12–18 years initially 30 mg daily in singleor divided doses until euthyroid then adjusted asnecessary (see notes above); higher initial dosesoccasionally required, particularly in thyrotoxiccrisisCounselling Warn child and carers to tell doctorimmediately if sore throat, mouth ulcers, bruising, fever,malaise, or non-specific illness developsCarbimazole (Non-proprietary) ATablets, carbimazole 5 mg, net price 100-tab pack =£4.53; 20 mg, 100-tab pack = £16.83. Counselling,blood disorder symptomsNeo-Mercazole c (Amdipharm) ATablets, both pink, carbimazole 5 mg, net price 100-tab pack = £3.85; 20 mg, 100-tab pack = £11.44.Counselling, blood disorder symptomsAdministration tablets may be crushed in water and usedimmediatelyExtemporaneous formulations available seeExtemporaneous Preparations, p. 6IODINE AND IODIDECautions not for long-term treatmentPregnancy neonatal goitre and hypothyroidism; seealso notes aboveBreast-feeding stop breast-feeding; danger of neonatalhypothyroidism or goitre; appears to be concentratedin milk; see also notes aboveSide-effects hypersensitivity reactions including coryza-likesymptoms, headache, lacrimation, conjunctivitis,pain in salivary glands, laryngitis, bronchitis,rashes; on prolonged treatment depression,insomnia, impotence; goitre in infants of motherstaking iodidesIndication and doseSee under preparationAqueous Iodine Oral SolutionOral solution, iodine 5%, potassium iodide 10% inpurified water, freshly boiled and cooled, total iodine130 mg/mL, net price 500 mL = £6.24. Label: 27DoseNeonatal thyrotoxicosis. By mouthNeonate 0.05–0.1 mL 3 times dailyThyrotoxicosis (pre-operative). By mouthNeonate 0.1–0.3 mL 3 times dailyChild 1 month–18 years 0.1–0.3 mL 3 times dailyThyrotoxic crisis. By mouthChild 1 month—1 year 0.2–0.3 mL 3 times dailyAdministration Dilute well with milk or waterPROPYLTHIOURACILCautions monitor for hepatotoxicityHepatotoxicity Severe hepatic reactions have beenreported, including fatal cases and cases requiring livertransplant—discontinue if significant liver-enzyme abnormalitiesdevelopCounselling Patients should be told how to recognise signsof liver disorder and advised to seek prompt medical attentionif symptoms such as anorexia, nausea, vomiting, fatigue,abdominal pain, jaundice, dark urine, or pruritus developHepatic impairment reduce dose (see also Hepatotoxicityabove)Renal impairment estimated glomerular filtrationrate 10–50 mL/minute/1.73 m 2 , use 75% of normaldose; estimated glomerular filtration rate less than10 mL/minute/1.73 m 2 , use 50% of normal dosePregnancy see notes aboveBreast-feeding monitor infant’s thyroid status butamount in milk probably too small to affect infant;high doses may affect neonatal thyroid function; seealso notes aboveSide-effects see under Carbimazole; leucopenia;rarely cutaneous vasculitis, thrombocytopenia,aplastic anaemia, hypoprothrombinaemia, hepaticdisorders (including hepatitis, hepatic failure,encephalopathy, hepatic necrosis; see also Hepatotoxicityabove), nephritis, lupus erythematous-likesyndromesLicensed use not licensed for use in children under 6years of ageIndication and doseHyperthyroidism (including Graves’ disease). By mouthNeonate initially 2.5–5 mg/kg twice daily untileuthyroid then adjusted as necessary (see notesabove); higher doses occasionally required, particularlyin thyrotoxic crisisChild 1 month–1 year initially 2.5 mg/kg 3 timesdaily until euthyroid then adjusted as necessary(see notes above); higher doses occasionallyrequired, particularly in thyrotoxic crisisChild 1–5 years initially 25 mg 3 times daily untileuthyroid then adjusted as necessary (see notesabove); higher doses occasionally required, particularlyin thyrotoxic crisis