BNF for Children 2011-2012

BNFC 2011–2012 15.1.5 Neuromuscular blocking drugs 643Side-effects Benzylisoquinolinium non-depolarisingneuromuscular blocking drugs (except cisatracurium)are associated with histamine release, which cancause skin flushing, hypotension, tachycardia, bronchospasm,and very rarely, anaphylactoid reactions. Mostaminosteroid neuromuscular blocking drugs produceminimal histamine release. Drugs with vagolytic activitycan counteract any bradycardia that occurs duringsurgery. Acute myopathy has also been reported afterprolonged use in intensive care.Atracurium, a mixture of 10 isomers, is a benzylisoquinoliniumneuromuscular blocking drug with an intermediateduration of action. It undergoes non-enzymaticmetabolism which is independent of liver and kidneyfunction, thus allowing its use in children with hepatic orrenal impairment. Cardiovascular effects are associatedwith significant histamine release. Neonates may bemore sensitive to the effects of atracurium and lowerdoses may be required.Cisatracurium is a single isomer of atracurium. It ismore potent and has a slightly longer duration of actionthan atracurium and provides greater cardiovascularstability because cisatracurium lacks histamine-releasingeffects. In children aged 1 month to 12 years,cisatracurium has a shorter duration of action andproduces faster spontaneous recovery.Mivacurium, a benzylisoquinolinium neuromuscularblocking drug, has a short duration of action. It ismetabolised by plasma cholinesterase and muscleparalysis is prolonged in individuals deficient in thisenzyme. It is not associated with vagolytic activity organglionic blockade although histamine release canoccur, particularly with rapid injection. In childrenunder 12 years mivacurium has a faster onset, shorterduration of action, and produces more rapid spontaneousrecovery.Pancuronium, an aminosteroid neuromuscular blockingdrug, has a long duration of action and is often usedin children receiving long-term mechanical ventilationin intensive care units. It lacks a histamine-releasingeffect, but vagolytic and sympathomimetic effects cancause tachycardia and hypertension. The half-life ofpancuronium is prolonged in neonates; neonates shouldreceive postoperative intermittent positive pressureventilation.Rocuronium exerts an effect within 2 minutes and hasthe most rapid onset of any of the non-depolarisingneuromuscular blocking drugs. It is an aminosteroidneuromuscular blocking drug with an intermediateduration of action. It is reported to have minimal cardiovasculareffects; high doses produce mild vagolyticactivity. In children under 12 years, rocuronium has afaster onset and shorter duration of action.Vecuronium, an aminosteroid neuromuscular blockingdrug, has an intermediate duration of action. It does notgenerally produce histamine release and lacks cardiovasculareffects. In neonates and infants, vecuroniumhas a faster onset and a longer duration of action;recovery is longer in these children. Unexpected sustainedneuromuscular blockade may occur in neonates.ATRACURIUM BESILATE(Atracurium besylate)Cautions see notes abovePregnancy see notes aboveBreast-feeding see notes aboveSide-effects see notes above; seizures also reportedLicensed use not licensed for use in neonatesIndication and doseTo avoid excessive dosage in obese children, doseshould be calculated on the basis of ideal weight forheightNeuromuscular blockade (short to intermediateduration) for surgery. By intravenous administrationNeonate initially by intravenous injection 300–500 micrograms/kg followed either by intravenousinjection, 100–200 micrograms/kg repeated asnecessary or by intravenous infusion, 300–400 micrograms/kg/hour adjusted according toresponseChild 1 month–18 years initially by intravenousinjection 300–600 micrograms/kg then 100–200 micrograms/kg repeated as necessary orinitially by intravenous injection 200–600 micrograms/kgfollowed by intravenous infusion, 300–600 micrograms/kg/hour adjusted according toresponseNeuromuscular blockade during intensive care. By intravenous administrationNeonate initially by intravenous injection 300–500 micrograms/kg followed either by intravenousinjection, 100–200 micrograms/kg repeated asnecessary or by intravenous infusion, 300–400 micrograms/kg/hour adjusted according toresponse; higher doses may be necessaryChild 1 month–18 years initially by intravenousinjection 300–600 micrograms/kg (optional) thenby intravenous infusion, 270–1770 micrograms/kg/hour (usual dose 650–780 micrograms/kg/hour)Administration for continuous intravenous infusion,dilute to a concentration of 0.5–5 mg/mL with Glucose5% or Sodium Chloride 0.9%; stability varieswith diluent.Neonatal intensive care, dilute 60 mg/kg body-weightto a final volume of 50 mL with Glucose 5% or SodiumChloride 0.9%; minimum concentration of 500 micrograms/mL,max. concentration of 5 mg/mL; anintravenous infusion rate of 0.1 mL/hour provides adose of 120 micrograms/kg/hourAtracurium (Non-proprietary) AInjection, atracurium besilate 10 mg/mL, net price2.5-mL amp = £1.85; 5-mL amp = £3.37; 25-mL vial=£14.45Tracrium c (GSK) AInjection, atracurium besilate 10 mg/mL, net price2.5-mL amp = £1.66; 5-mL amp = £3.00; 25-mL vial =£12.91CISATRACURIUMCautions see notes abovePregnancy see notes aboveBreast-feeding see notes aboveSide-effects see notes above; also bradycardia15 Anaesthesia