BNF for Children 2011-2012

94 2.5.1 Vasodilator antihypertensive drugs BNFC 2011–20122 Cardiovascular systemContra-indications idiopathic systemic lupus erythematosus,severe tachycardia, high output heart failure,myocardial insufficiency due to mechanical obstruction,cor pulmonale; acute porphyria (section 9.8.2)Hepatic impairment reduce doseRenal impairment reduce dose if estimated glomerularfiltration rate less than 30 mL/minute/1.73 m 2Pregnancy neonatal thrombocytopenia reported, butrisk should be balanced against risk of uncontrolledmaternal hypertension; manufacturer advises avoidbefore third trimesterBreast-feeding present in milk but not known to beharmful; monitor infantSide-effects tachycardia, palpitation, flushing, hypotension,fluid retention, gastro-intestinal disturbances;headache, dizziness; systemic lupus erythematosuslikesyndrome after long-term therapy (especially inslow acetylator individuals); rarely rashes, fever, peripheralneuritis, polyneuritis, paraesthesia, arthralgia,myalgia, increased lacrimation, nasal congestion,dyspnoea, agitation, anxiety, anorexia; blood disorders(including leucopenia, thrombocytopenia,haemolytic anaemia), abnormal liver function, jaundice,raised plasma creatinine, proteinuria and haematuriareportedLicensed use not licensed for use in childrenIndication and doseHypertension. By mouthNeonate 250–500 micrograms/kg every 8–12hours increased as necessary to max. 2–3 mg/kgevery 8 hoursChild 1 month–12 years 250–500 micrograms/kg every 8–12 hours increased as necessary tomax. 7.5 mg/kg daily (not exceeding 200 mg daily)Child 12–18 years 25 mg twice daily, increased tousual max. 50–100 mg twice daily. By slow intravenous injectionNeonate 100–500 micrograms/kg repeated every4–6 hours as necessary; max. 3 mg/kg dailyChild 1 month–12 years 100–500 micrograms/kg repeated every 4–6 hours as necessary; max.3 mg/kg daily (not exceeding 60 mg daily)Child 12–18 years 5–10 mg repeated every 4–6hours as necessary. By continuous intravenous infusion (preferredroute in cardiac patients)Neonate 12.5–50 micrograms/kg/hour; max.2 mg/kg dailyChild 1 month–12 years 12.5–50 micrograms/kg/hour; max. 3 mg/kg dailyChild 12–18 years 3–9 mg/hour; max. 3 mg/kgdailyAdministration for intravenous injection, initiallyreconstitute 20 mg with 1 mL Water for Injections,then dilute to a concentration of 0.5–1 mg/mL withSodium Chloride 0.9% and administer over 5–20minutes.For continuous intravenous infusion, initially reconstitute20 mg with 1 mL Water for Injections, thendilute with Sodium Chloride 0.9%. Incompatible withGlucose intravenous infusion.For administration by mouth, diluted injection may begiven orallyHydralazine (Non-proprietary) ATablets, hydralazine hydrochloride 25 mg, net price56-tab pack = £9.32; 50 mg, 56-tab pack = £16.84Apresoline c (Amdipharm) ATablets, yellow, s/c, hydralazine hydrochloride 25 mg,net price 84-tab pack = £3.38Excipients include gluten, propylene glycol (see Excipients, p. 2)Injection, powder for reconstitution, hydralazinehydrochloride, net price 20-mg amp = £2.22Extemporaneous formulations available seeExtemporaneous Preparations, p. 6MINOXIDILCautions see notes above; acute porphyria (section9.8.2); interactions: Appendix 1 (vasodilator antihypertensives)Contra-indications phaeochromocytomaRenal impairment use with caution in significantimpairmentPregnancy avoid—possible toxicity including reducedplacental perfusion; neonatal hirsutism reportedBreast-feeding present in milk but not known to beharmfulSide-effects sodium and water retention; weight gain,peripheral oedema, tachycardia, hypertrichosis;reversible rise in creatinine and blood urea nitrogen;occasionally, gastro-intestinal disturbances, breasttenderness, rashesIndication and doseSevere hypertension. By mouthChild 1 month–12 years initially 200 micrograms/kgdaily in 1–2 divided doses, increased insteps of 100–200 micrograms/kg daily at intervalsof at least 3 days; max. 1 mg/kg dailyChild 12–18 years initially 5 mg daily in 1–2divided doses increased in steps of 5–10 mg atintervals of at least 3 days; max. 100 mg daily(seldom necessary to exceed 50 mg daily)Loniten c (Pharmacia) ATablets, scored, minoxidil 2.5 mg, net price 60-tabpack = £8.88; 5 mg, 60-tab pack = £15.83; 10 mg, 60-tab pack = £30.68Extemporaneous formulations available seeExtemporaneous Preparations, p. 6SODIUM NITROPRUSSIDECautions hypothyroidism, hyponatraemia, impairedcerebral circulation, hypothermia; monitor bloodpressure and blood-cyanide concentration, and iftreatment exceeds 3 days also blood-thiocyanateconcentration; avoid sudden withdrawal—terminateinfusion over 15–30 minutes; interactions: Appendix1 (nitroprusside)Contra-indications severe vitamin B 12 deficiency;Leber’s optic atrophy; compensatory hypertension