BNF for Children 2011-2012

BNFC 2011–2012 2.1.2 Phosphodiesterase type-3 inhibitors 75Child 10–18 years initially 0.5–1 mg in 3 divideddoses for 24 hours then 62.5–250 micrograms dailyin 1–2 divided doses (higher doses may be necessary)Note The above doses may need to be reduced if digoxin (oranother cardiac glycoside) has been given in the preceding 2weeks. When switching from intravenous to oral route mayneed to increase dose by 20–30% to maintain the sameplasma-digoxin concentration. Plasma monitoring may berequired when changing formulation to take account ofvarying bioavailabilities. For plasma concentration monitoring,blood should ideally be taken at least 6 hours after a doseAdministration for intravenous infusion, dilute withSodium Chloride 0.9% or Glucose 5% to a max.concentration of 62.5 micrograms/mL; loading dosesshould be given over 30–60 minutes and maintenancedose over 10–20 minutes.For oral administration, oral solution must not bedilutedDigoxin (Non-proprietary) ATablets, digoxin 62.5 micrograms, net price 28-tabpack = £2.03; 125 micrograms, 28-tab pack = £1.12;250 micrograms, 28-tab pack = £1.13Injection, digoxin 250 micrograms/mL, net price 2-mL amp = 70pExcipients include alcohol, propylene glycol (see Excipients, p. 2)Paediatric injection, digoxin 100 micrograms/mLAvailable from ‘special-order’ manufacturers or specialistimporting companies, see p. 809Lanoxin c (Aspen) ATablets, digoxin 125 micrograms, net price 500-tabpack = £8.09; 250 micrograms (scored), 500-tab pack= £8.09Injection, digoxin 250 micrograms/mL, net price 2-mL amp = 66pLanoxin-PG c (Aspen) ATablets, blue, digoxin 62.5 micrograms, net price 500-tab pack = £8.09Elixir, yellow, digoxin 50 micrograms/mL. Do notdilute, measure with pipette. Net price 60 mL = £5.35.Counselling, use of pipetteDigoxin-specific antibodyDigoxin-specific antibody fragments are indicated forthe treatment of known or strongly suspected digoxin ordigitoxin overdosage when measures beyond the withdrawalof the cardiac glycoside and correction of anyelectrolyte abnormalities are felt to be necessary (seealso notes above).Digibind c (GSK) AInjection, powder for preparation of infusion, digoxinspecificantibody fragments (F(ab)) 38 mg. Net priceper vial = £93.97 (hosp. and poisons centres only)DoseConsult product literature or Poisons Information Centre2.1.2 Phosphodiesterase type-3 inhibitorsEnoximone and milrinone are phosphodiesterase type-3 inhibitors that exert most of their effect on the myocardium.They possess positive inotropic and vasodilatoractivity and are useful in infants and children withlow cardiac output especially after cardiac surgery.Phosphodiesterase type-3 inhibitors should be limitedto short-term use because long-term oral administrationhas been associated with increased mortality in adultswith congestive heart failure.ENOXIMONECautions heart failure associated with hypertrophiccardiomyopathy, stenotic or obstructive valvular diseaseor other outlet obstruction; monitor blood pressure,heart rate, ECG, central venous pressure, fluidand electrolyte status, renal function, platelet count,hepatic enzymes; avoid extravasation; interactions:Appendix 1 (phosphodiesterase type-3 inhibitors)Hepatic impairment dose reduction may be requiredRenal impairment consider dose reductionPregnancy manufacturer advises use only if potentialbenefit outweighs riskBreast-feeding manufacturer advises caution—noinformation availableSide-effects ectopic beats; less frequently ventriculartachycardia or supraventricular arrhythmias (morelikely in children with pre-existing arrhythmias);hypotension; also headache, insomnia, nausea andvomiting, diarrhoea; occasionally, chills, oliguria,fever, urinary retention; upper and lower limb painLicensed use not licensed for use in childrenIndication and doseCongestive heart failure, low cardiac outputfollowing cardiac surgery. By intravenous injection and continuous intravenousinfusionNeonate initial loading dose of 500 micrograms/kg by slow intravenous injection, followed by 5–20 micrograms/kg/minute by continuous intravenousinfusion over 24 hours adjusted accordingto response; max 24 mg/kg over 24 hoursChild 1 month–18 years initial loading dose of500 micrograms/kg by slow intravenous injection,followed by 5–20 micrograms/kg/minute by continuousintravenous infusion over 24 hoursadjusted according to response; max. 24 mg/kgover 24 hoursAdministration for intravenous administration, diluteto concentration of 2.5 mg/mL with Sodium Chloride0.9% or Water for Injections; the initial loading doseshould be given by slow intravenous injection over atleast 15 minutes. Use plastic apparatus—crystal formationif glass usedPerfan c (INCA-Pharm) AInjection, enoximone 5 mg/mL. For dilution beforeuse. Net price 20-mL amp = £15.02Excipients include alcohol, propylene glycol (see Excipients, p. 2)MILRINONECautions see under Enoximone; also correct hypokalaemia;monitor renal function; interactions:Appendix 1 (phosphodiesterase type-3 inhibitors)Renal impairment use half to three-quarters normaldose and monitor response if estimated glomerularfiltration rate less than 50 mL/minute/1.73 m 2Pregnancy manufacturer advises use only if potentialbenefit outweighs risk2 Cardiovascular system