BNF for Children 2011-2012

236 4.9.1 Dopaminergic drugs used in dystonias BNFC 2011–20124 Central nervous systemdihydrobiopterin reductase deficiency. For the use oftetrahydrobiopterin in metabolic disorders see section9.4.1.Children may experience nausea within 2 hours oftaking a dose; nausea and vomiting with co-careldopais rarely dose-limiting, but domperidone (section 4.6)can be useful in controlling these effects.In dystonic cerebral palsy, treatment with larger dosesof levodopa is associated with the development ofpotentially troublesome motor complications (includingresponse fluctuations and dyskinesias). Response fluctuationsare characterised by large variations in motorperformance, with normal function during the ‘on’ period,and weakness and restricted mobility during the‘off’ period.Sudden onset of sleepExcessive daytime sleepiness and sudden onset ofsleep can occur with co-careldopa.Children starting treatment with these drugs, andtheir carers, should be warned of the risk and of theneed to exercise caution when performing skilledtasks e.g. driving or operating machinery. Childrenwho have experienced excessive sedation or suddenonset of sleep should refrain from performing skilledtasks until these effects have stopped occurring.Management of excessive daytime sleepiness shouldfocus on the identification of an underlying cause,such as depression or concomitant medication. Children,and their carers, should be counselled onimproving sleep behaviour.Licensed use not licensed for use in childrenIndication and doseDopamine-sensitive dystonias including Segawasyndrome and dystonias related to cerebralpalsy. By mouth, expressed as levodopaChild 3 months–18 years initially 250 micrograms/kg2–3 times daily of a preparation containing1:4 carbidopa:levodopa, increased accordingto response every 2–3 days to max. 1 mg/kgthree times dailyTreatment of defects in tetrahydrobiopterinsynthesis and dihydrobiopterin reductasedeficiency. By mouth, expressed as levodopaNeonate initially 250–500 micrograms/kg 4 timesdaily of a preparation containing 1:4 carbidopa:-levodopa, increased according to response every4–5 days to maintenance dose of 2.5–3 mg/kg 4times daily; at higher doses consider preparationcontaining 1:10 carbidopa:levodopa; review regularly(every 3–6 months)Child 1 month–18 years initially 250–500 micrograms/kg4 times daily of a preparation containing1:4 carbidopa:levodopa, increased accordingto response every 4–5 days to maintenancedose of 2.5–3 mg/kg 4 times daily; at higher dosesconsider preparation containing 1:10 carbidopa:-levodopa; review regularly (every 3–6 months inearly childhood)CO-CARELDOPAA mixture of carbidopa and levodopa; the proportions areexpressed in the form x/y where x and y are the strengths inmilligrams of carbidopa and levodopa respectivelyCautions see also notes above; pulmonary disease,peptic ulceration, cardiovascular disease (includinghistory of myocardial infarction with residualarrhythmia), diabetes mellitus, osteomalacia, susceptibilityto angle-closure glaucoma, history of skinmelanoma (risk of activation), psychiatric illness(avoid if severe and discontinue if deterioration); warnchildren and carers about excessive drowsiness (seenotes above); in prolonged therapy, psychiatric,hepatic, haematological, renal, and cardiovascularsurveillance is advisable; warn patients to resumenormal activities gradually; avoid abrupt withdrawal;interactions: Appendix 1 (levodopa)Pregnancy use with caution—toxicity in animal studiesBreast-feeding may suppress lactation; present inmilk—avoidSide-effects see also notes above; anorexia, nauseaand vomiting, insomnia, agitation, postural hypotension(rarely labile hypertension), dizziness, tachycardia,arrhythmias, reddish discoloration of urine andother body fluids; rarely hypersensitivity; very rarelyangle-closure glaucoma; abnormal involuntarymovements and psychiatric symptoms which includehypomania and psychosis may be dose-limiting;depression, drowsiness, headache, flushing, sweating,gastro-intestinal bleeding, peripheral neuropathy,taste disturbance, pruritus, rash, and liver enzymechanges also reported; syndrome resembling neurolepticmalignant syndrome reported on withdrawalCo-careldopa (Non-proprietary) ATablets, co-careldopa 10/100 (carbidopa 10 mg(anhydrous), levodopa 100 mg), net price 100-tabpack = £7.30. Label: 14, counselling, skilled tasks, seenotes aboveTablets, co-careldopa 25/100 (carbidopa 25 mg(anhydrous), levodopa 100 mg), net price 100-tabpack = £24.45. Label: 14, counselling, skilled tasks, seenotes aboveTablets, co-careldopa 25/250 (carbidopa 25 mg(anhydrous), levodopa 250 mg), net price 100-tabpack = £34.58. Label: 14, counselling, skilled tasks, seenotes aboveSinemet c (MSD) ASinemet-62.5 c tablets, yellow, scored, co-careldopa12.5/50 (carbidopa 12.5 mg (anhydrous), levodopa50 mg), net price 90-tab pack = £6.28. Label: 14,counselling, skilled tasks, see notes aboveNote 2 tablets Sinemet-62.5 c : 1 tablet Sinemet Plus c ;Sinemet-62.5 c previously known as Sinemet LS cSinemet-110 c tablets, blue, scored, co-careldopa10/100 (carbidopa 10 mg (anhydrous), levodopa100 mg), net price 90-tab pack = £6.57. Label: 14,counselling, skilled tasks, see notes aboveSinemet-Plus c tablets, yellow, scored, co-careldopa25/100 (carbidopa 25 mg (anhydrous), levodopa100 mg), net price 90-tab pack = £9.66. Label: 14,counselling, skilled tasks, see notes aboveSinemet-275 c tablets, blue, scored, co-careldopa25/250 (carbidopa 25 mg (anhydrous), levodopa250 mg), net price 90-tab pack = £13.72. Label: 14,counselling, skilled tasks, see notes above