BNF for Children 2011-2012

218 4.8.1 Control of the epilepsies BNFC 2011–20124 Central nervous systemCARBAMAZEPINECautions cardiac disease (see also Contra-indications);skin reactions (see also Blood, Hepatic, or Skin disorders,below and under Side-effects); test for HLA-B*1502 allele in individuals of Han Chinese or Thaiorigin (avoid unless no alternative—risk of Stevens-Johnson syndrome in the presence of HLA-B*1502allele); history of haematological reactions to otherdrugs; manufacturer recommends blood counts andhepatic and renal function tests (but evidence ofpractical value uncertain); may exacerbate absenceand myoclonic seizures; consider vitamin D supplementationin patients who are immobilised for longperiods or who have inadequate sun exposure ordietary intake of calcium; susceptibility to angle-closureglaucoma; cross-sensitivity reported with oxcarbazepine,and with phenytoin; avoid abrupt withdrawal;interactions: see p. 215 and Appendix 1(carbamazepine)Blood, hepatic, or skin disorders Children or their carersshould be told how to recognise signs of blood, liver, or skindisorders, and advised to seek immediate medical attention ifsymptoms such as fever, rash, mouth ulcers, bruising, orbleeding develop. Carbamazepine should be withdrawnimmediately in cases of aggravated liver dysfunction or acuteliver disease. Leucopenia that is severe, progressive, orassociated with clinical symptoms requires withdrawal (ifnecessary under cover of a suitable alternative).Contra-indications AV conduction abnormalities(unless paced); history of bone marrow depression,acute porphyria (section 9.8.2)Hepatic impairment metabolism impaired inadvanced liver disease; see also Blood, Hepatic, orSkin Disorders, aboveRenal impairment use with cautionPregnancy see Pregnancy, p. 216Breast-feeding amount probably too small to beharmful but monitor infant for possible adversereactions; see also Breast-feeding, p. 217Side-effects see notes above; also dry mouth, nausea,vomiting, oedema, ataxia, dizziness, drowsiness, fatigue,headache, hyponatraemia (leading in rare casesto water intoxication), blood disorders (includingeosinophilia, leucopenia, thrombocytopenia, haemolyticanaemia, and aplastic anaemia), dermatitis,urticaria; less commonly diarrhoea, constipation,involuntary movements (including nystagmus), visualdisturbances; rarely abdominal pain, anorexia,hepatitis, jaundice, vanishing bile duct syndrome,cardiac conduction disorders, hypertension, hypotension,peripheral neuropathy, dysarthria, aggression,agitation, confusion, depression, hallucinations,restlessness, paraesthesia, lymph node enlargement,muscle weakness, systemic lupus erythematosus,delayed multi-organ hypersensitivity disorder; veryrarely pancreatitis, stomatitis, hepatic failure, tastedisturbance, exacerbation of coronary artery disease,AV block with syncope, circulatory collapse, hypercholesterolaemia,thrombophlebitis, thromboembolism,pulmonary hypersensitivity (with dyspnoea,pneumonitis, or pneumonia), psychosis, neurolepticmalignant syndrome, osteomalacia (see Cautions),osteoporosis, galactorrhoea, gynaecomastia,impaired male fertility, interstitial nephritis, renalfailure, sexual dysfunction, urinary frequency, urinaryretention, arthralgia, muscle pain, muscle spasm,conjunctivitis, angle-closure glaucoma, hearing disorders,acne, alterations in skin pigmentation, alopecia,hirsutism, sweating, photosensitivity, purpura,Stevens-Johnson syndrome, toxic epidermal necrolysis,aseptic meningitis; suicidal ideationPharmacokinetics plasma concentration for optimumresponse 4–12 mg/litre (20–50 micromol/litre) measured after 1–2 weeksLicensed use suppositories not licensed for use intrigeminal neuralgia or prophylaxis of bipolar disorderIndication and doseFocal and generalised tonic-clonic seizures,trigeminal neuralgia, prophylaxis of bipolardisorder. By mouthChild 1 month–12 years initially 5 mg/kg at nightor 2.5 mg/kg twice daily, increased as necessaryby 2.5–5 mg/kg every 3–7 days; usual maintenancedose 5 mg/kg 2–3 times daily; doses up to20 mg/kg daily have been usedChild 12–18 years initially 100–200 mg 1–2 timesdaily, increased slowly to usual maintenance dose200–400 mg 2–3 times daily; in some cases dosesup to 1.8 g daily may be needed. By rectumChild 1 month–18 years use approx. 25% morethan the oral dose (max. 250 mg) up to 4 timesdailyNote Different preparations may vary in bioavailability; toavoid reduced effect or excessive side-effects, it may beprudent to avoid changing the formulationAdministration Oral liquid has been used rectally—should be retained for at least 2 hours (but may havelaxative effect)Carbamazepine (Non-proprietary) ATablets, carbamazepine 100 mg, net price 28 = £5.69;200 mg, 28 = £4.99; 400 mg, 28 = £6.59. Label: 3, 8,counselling, blood, hepatic or skin disorder symptoms(see above), driving (see notes above)Brands include Epimaz cDental prescribing on NHS Carbamazepine Tablets may beprescribedTegretol c (Novartis) ATablets, scored, carbamazepine 100 mg, net price 84-tab pack = £2.07; 200 mg, 84-tab pack = £3.83;400 mg, 56-tab pack = £5.02. Label: 3, 8, counselling,blood, hepatic or skin disorder symptoms (see above),driving (see notes above)Chewtabs, orange, carbamazepine 100 mg, net price56-tab pack = £3.16; 200 mg, 56-tab pack = £5.88.Label: 3, 8, 21, 24, counselling, blood, hepatic or skindisorder symptoms (see above), driving (see notesabove)Liquid, sugar-free, carbamazepine 100 mg/5 mL. Netprice 300-mL pack = £6.12. Label: 3, 8, counselling,blood, hepatic or skin disorder symptoms (see above),driving (see notes above)Suppositories, carbamazepine 125 mg, net price 5 =£8.03; 250 mg, 5 = £10.71. Label: 3, 8, counselling,blood, hepatic or skin disorder symptoms (see above),driving (see notes above)DoseEpilepsy for short-term use (max. 7 days) when oraltherapy temporarily not possibleNote Suppositories of 125 mg may be considered to beapproximately equivalent in therapeutic effect to tablets of100 mg but final adjustment should always depend on clin-