BNF for Children 2011-2012

BNFC 2011–2012 15.1.3 Antimuscarinic drugs 635NITROUS OXIDECautions see notes above; interactions: Appendix 1(anaesthetics, general)Pregnancy may depress neonatal respiration if usedduring deliveryBreast-feeding breast-feeding can be resumed assoon as mother has recovered sufficiently fromanaesthesiaSide-effects see notes aboveIndication and doseMaintenance of anaesthesia in conjunctionwith other anaesthetic agents. By inhalation using suitable anaesthetic apparatusNeonate 50–66% in oxygenChild 1 month–18 years 50–66% in oxygenAnalgesia. By inhalation using suitable anaesthetic apparatus(see also notes above)Neonate up to 50% in oxygen, according to thechild’s needsChild 1 month–18 years up to 50% in oxygen,according to the child’s needs15.1.3 Antimuscarinic drugsImportantThe drugs in this section should be used by experiencedpersonnel only.Antimuscarinic drugs are used (less commonly nowadays)as premedicants to dry bronchial and salivarysecretions which are increased by intubation, upperairway surgery, or some inhalational anaesthetics, butthey should not be used for this indication in childrenwith cystic fibrosis. Antimuscarinics are also used beforeor with neostigmine (section 15.1.6) to prevent bradycardia,excessive salivation, and other muscarinicactions of neostigmine. They also prevent bradycardiaand hypotension associated with drugs such as halothane,propofol, and suxamethonium.Atropine sulphate is now rarely used for premedicationbut still has an emergency role in the treatment ofvagotonic side-effects. For its role in cardiopulmonaryresuscitation, see section 2.7.3.Hyoscine hydrobromide reduces secretions and alsoprovides a degree of amnesia, sedation and anti-emesis.Unlike atropine it may produce bradycardia rather thantachycardia. In some children hyoscine may cause thecentral anticholinergic syndrome (excitement, ataxia,hallucinations, behavioural abnormalities, and drowsiness).Glycopyrronium bromide reduces salivary secretions.When given intravenously it produces less tachycardiathan atropine. It is widely used with neostigmine forreversal of non-depolarising muscle relaxants (section15.1.5).Glycopyrronium or hyoscine hydrobromide are alsoused to control excessive secretions in upper airwaysor hypersalivation in palliative care and in childrenunable to control posture or with abnormal swallowingreflex; effective dose varies and tolerance may develop.The intramuscular route should be avoided if possible.Hyoscine transdermal patches may also be used (section4.6).ATROPINE SULPHATECautions see notes in section 1.2Duration of action Since atropine has a shorter duration ofaction than neostigmine, late unopposed bradycardia mayresult; close monitoring of the patient is necessaryContra-indications see notes in section 1.2Pregnancy not known to be harmful; use with cautionBreast-feeding small amount present in milk—usewith cautionSide-effects see notes in section 1.2Licensed use not licensed for use by oral route; notlicensed for use in children under 12 years for intraoperativebradycardia; not licensed for use in childrenunder 12 years by intravenous route for premedication;not licensed for the control of muscarinicside-effects of edrophonium in reversal ofcompetitive neuromuscular blockIndication and dosePremedication. By mouth 1–2 hours before induction ofanaesthesiaNeonate 20–40 micrograms/kgChild 1 month–18 years 20–40 micrograms/kg(max. 900 micrograms). By intravenous injection immediately beforeinduction of anaesthesiaNeonate 10 micrograms/kgChild 1 month–12 years 20 micrograms/kg(minimum 100 micrograms, max. 600 micrograms)Child 12–18 years 300–600 micrograms. By subcutaneous or intramuscular injection30–60 minutes before induction of anaesthesiaNeonate 10 micrograms/kgChild 1 month–12 years 10–30 micrograms/kg(minimum 100 micrograms, max. 600 micrograms)Child 12–18 years 300–600 microgramsIntra-operative bradycardia. By intravenous injectionNeonate 10–20 micrograms/kgChild 1 month–12 years 10–20 micrograms/kgChild 12–18 years 300–600 micrograms (largerdoses in emergencies)Control of muscarinic side-effects of neostigmine50 micrograms/kg in reversal of competitiveneuromuscular block. By intravenous injectionNeonate 20 micrograms/kgChild 1 month–12 years 20 micrograms/kg(max. 1.2 mg)Child 12–18 years 0.6–1.2 mg15 Anaesthesia