Tegretol

Carbamazepine

As monotherapy or combination therapy for partial seizures (simple or complex, w/ or w/o loss of consciousness), w/ or w/o secondary generalization; generalized tonic-clonic seizures; mixed forms of seizures. Acute mania & maintenance treatment of bipolar affective disorders to prevent or attenuate recurrence. Alcohol-withdrawal syndrome. Idiopathic trigeminal neuralgia & trigeminal neuralgia secondary to multiple sclerosis (typical or atypical). Idiopathic glossopharyngeal neuralgia.

Epilepsy Adult Initially 100-200 mg once daily or bd, slowly increasing until optimum response is achieved (generally 400 mg bd or tds). Childn & adolescent Oral susp 10-20 mg/kg/day in divided doses. Max recommended dose: 1,200 mg/day for childn >15 yr, 1,000 mg/day for childn 6-15 yr, 35 mg/kg/day for childn up to 6 yr. Childn >4 yr Initially 100 mg/day, increasing by 100 mg at wkly intervals, ≤4 yr Initially 20-60 mg/day, increasing by 20-60 mg every 2nd day. Trigeminal neuralgia Initially 200-400 mg/day (in elderly, 100 mg bd) increased gradually until freedom from pain is achieved, then reduce dose to the lowest possible maintenance level. Max: 1,200 mg/day. Alcohol-withdrawal syndrome 200 mg tds-qds on the 1st 2 days of treatment. In severe cases, may be increased to 1,200 mg/day during the 1st few days of treatment. Acute mania & maintenance treatment of bipolar affective disorders Approx 400-1,600 mg daily. Normal daily dose: 400-600 mg, given in 2-3 divided doses. The dosage should be increased fairly rapidly in acute mania, whereas small increments are recommended for maintenance therapy of bipolar disorders.

Should be taken with food: Avoid grapefruit juice. CR divitab: May be halved along the score-line. Do not chew/crush.

Hypersensitivity to carbamazepine & oxcarbazepine, structurally-related drugs (eg, TCAs), or to parabens. Patients w/ AV block, bone-marrow depression or a history of hepatic porphyria (eg, acute intermittent porphyria, variegate porphyria, porphyria cutanea tarda). Not recommended in combination w/ MAOIs. MAOIs should be discontinued a min of 2 wk before initiating Tegretol. Syr: Fructose intolerance (hereditary problems of fructose intolerance).

Prior or existing haematological disease, history of haematological adverse reactions to other drugs; impaired Na metabolism; patients w/ current or previous heart, liver or kidney disease. Determine complete blood counts (including platelets, reticulocytes & serum Fe) at baseline & at regular intervals thereafter. Discontinue if there is any evidence of significant bone marrow depression. Rare reports of severe dermatological reactions, including toxic epidermal necrolysis & SJS; w/draw Tegretol once signs of severe skin reactions are ascertained. Should not be used in patients who test positive for the presence of HLA-A*3101 or HLA-B*1502 alleles unless the benefits clearly outweigh the risks. Discontinue at any signs of hypersensitivity or systemic hypersensitivity reactions. Should not be used in patients w/ absences or mixed seizures (including typical & atypical absences). Perform baseline & periodic evaluation of hepatic function before & during treatment, particularly in patients w/ history of liver disease & in elderly patients. Baseline & periodic complete urinalysis & BUN determinations are recommended. Risk of hyponatremia. May reduce serum conc of thyroid hormones. Presence of slight anticholinergic activity. Possibility of activation of latent psychosis, & of confusion & agitation (particularly in elderly patients). Monitor patients for suicidal ideation & behaviour. Risk of photosensitization. Concomitant use w/ CYP3A4 inhibitors, inducers or substrates; epoxide hydrolase inhibitors; direct-acting anticoagulants. Abrupt w/drawal may lead to seizures. Associated w/ ataxia, dizziness, somnolence, hypotension, confusional state or sedation. Exercise caution when driving or using machines. Congenital malformations may occur. Women of childbearing potential should use reliable contraception during treatment & for 2 wk after the last dose. Reports of breakthrough bleeding in women taking OCs. Pregnancy & lactation.

Leukopenia; dizziness, ataxia, somnolence; nausea, vomiting; allergic dermatitis, pruritus, urticaria; fatigue; γ-glutamyltransferase increased. Eosinophilia, thrombocytopenia; oedema, fluid retention, wt gain, hyponatraemia, reduced plasma osmolality; headache, diplopia; accommodation disorders; dry mouth; elevated alkaline phosphatase.

Raised plasma levels of carbamazepine w/ isoniazid; verapamil, diltiazem; dextropropoxyphene, ibuprofen; possibly desipramine, viloxazine, fluoxetine, fluvoxamine, trazodone, paroxetine; possibly cimetidine, omeprazole; acetazolamide; danazol; macrolide antibiotics (eg, erythromycin, troleandomycin, josamycin, clarithromycin, ciprofloxacin); azole derivatives (eg, itraconazole, ketoconazole, fluconazole, voriconazole); terfenadine, loratadine; HIV protease inhibitors (eg, ritonavir); stiripentol, vigabatrin; loxapine, olanzapine, quetiapine; oxybutynin, dantrolene; ticlopidine; grapefruit juice, nicotinamide (only at high doses). Raised plasma levels of carbamazepine-10,11-epoxide w/ loxapine, quetiapine, primidone, progabide, valproate, valnoctamide, valpromide. Lowered plasma levels of carbamazepine w/ phenobarb, primidone, methsuximide, felbamate, oxcarbazepine, phensuximide, phenytoin, fosphenytoin, clonazepam; cisplatin, doxorubicin; rifampicin; theophylline, aminophylline; isotretinoin; herbal prep containing St John's wort (Hypericum perforatum). Dosage of the following drugs may be adjusted to meet clinical requirements: Buprenorphine, methadone, fentanyl, paracetamol, phenazone (antipyrine), tramadol; doxycycline, rifabutin; oral anticoagulants; TCAs, bupropion, citalopram, mianserin, nefazodone, sertraline, trazodone; aprepitant; clobazam, clonazepam, ethosuximide, felbamate, lamotrigine, eslicarbazepine, oxcarbazepine, primidone, tiagabine, topiramate, valproate, zonisamide; itraconazole, ketoconazole, voriconazole; praziquantel, albendazole; imatinib, cyclophosphamide, lapatinib, temsirolimus; clozapine, haloperidol, bromperidol, olanzapine, quetiapine, risperidone, ziprasidone, aripiprazole, paliperidone; HIV protease inhibitors (eg, indinavir, ritonavir, saquinavir); alprazolam, midazolam; theophylline; Ca channel blockers (dihydropyridine group) eg, felodipine; digoxin, quinidine, propranolol, simvastatin, atorvastatin, lovastatin, cerivastatin, ivabradine; corticosteroids eg, prednisolone, dexamethasone; ciclosporin, tacrolimus, everolimus, sirolimus; tadalafil. Potential hepatotoxicity w/ long-term administration of carbamazepine & paracetamol. May lower plasma levels of bupropion & raise its metabolite hydroxybupropion. Enhanced elimination of thyroid hormones. Attenuated effect of hormonal contraceptives. Increased toxicity w/ levetiracetam; INH. Potentiated neurotoxic effects of lithium & metoclopramide. Increased neuroleptic malignant syndrome or SJS w/ neuroleptic therapy. Symptomatic hyponatraemia w/ diuretics (hydrochlorothiazide, furosemide). Antagonized effects of non-depolarizing muscle relaxants (eg, pancuronium). Reduced alcohol tolerance. Reduced plasma conc of direct acting oral anti-coagulants. False positive perphenazine conc in HPLC analysis. False positive TCA conc in fluorescence polarized immunoassays.

Anticonvulsants / Drugs for Neuropathic Pain

N03AF01 - carbamazepine ; Belongs to the class of carboxamide derivatives antiepileptic.

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