A CASE OF INTOXICATION WITH TEGRETOL

Phenomenology and treatment of tremor disorders

Tremor is classified according to anatomic distribution among body parts, and by frequency and amplitude during rest, postural maintenance, movement, intention, and the performance of specific tasks. Key historical features include age at onset, progression over time, family history, exacerbating and remitting factors and behaviors, response to alcohol and medications, and additional neurological signs and symptoms. Accurate diagnosis is a critical factor in predicting the natural history and response to treatment.

Carbamazepine toxicity and poisoning. Incidence, clinical features and management

Carbamazepine is the drug of first choice in the treatment of simple and complex partial seizures and trigeminal and glossopharyngeal neuralgias. It is usually preferred to phenobarbitone or phenytoin because of its powerful antiepileptic activity combined with a relative lack of adverse effects. In this article the mechanisms of action and pharmacological properties of carbamazepine are outlined in order to explain the pathogenesis of most side and toxic effects. Most of these effects, namely those affecting the nervous or cardiovascular systems, correlate well with an increased concentration of the drug in plasma and disappear spontaneously upon discontinuation of therapy. Other, less frequent toxic effects, namely aplastic anaemia or fatal hepatitis, may be ascribed to unforeseeable idiosyncratic reactions. Carbamazepine poisoning, usually accidental and sometimes secondary to the coadministration of other drugs, yields a clinical picture with neurological and cardiovascular signs. The outcome is usually favourable, sometimes with spontaneous improvement, and death is a distinct rarity. No specific antidotes are available. The oral administration of activated charcoal has been shown to be an effective therapeutic measure significantly reducing the plasma half-life of the drug.

Carbamazepine-induced nonepileptic myoclonus in a child with benign epilepsy

Myoclonic jerks involving the proximal limb musculature and tic-like movements (sniffing, coughing, or sighing) were observed in an 11-year-old boy with benign occipital epilepsy treated with carbamazepine (CBZ). The involuntary movements disappeared a few days after withdrawal of CBZ and reappeared with CBZ reintroduction. Plasma CBZ levels were always within the therapeutic range. Polygraphic studies failed to show any electroencephalogram (EEG) changes during myoclonic jerks. Appearance of nonepileptic myoclonus in epileptic children treated with CBZ should be carefully evaluated to prevent worsening of the clinical picture. The coexistence of other involuntary movements (tics) could suggest the correct diagnosis.

Carbamazepine toxicity: comparison of measurement of drug levels by HPLC and EMIT and model of carbamazepine kinetics

A 23-month-old boy accidently ingested 2000 mg (148 mg/kg) of carbamazepine. The delayed onset of convulsions coincided with the peak serum level of total parent drug and an active metabolite (carbamazepine 10,11-epoxide). Comparisons of homogeneous enzyme multiplied immunoassay technique (EMIT) and high pressure liquid chromatography (HPLC) revealed that the EMIT slightly over-estimated plasma carbamazepine levels due to immunochemical cross reactivity with the epoxide metabolite. The peak plasma levels of the parent drug plus the active metabolite were more accurately determined by HPLC. These results emphasize the need to understand both the presence of active metabolites and characteristics of the assay being used in managing clinical intoxication with carbamazepine.

Carbamezepine poisoning, a surprisingly severe case

A case of carbamazepine (Tegretol) poisoning is presented. The symptoms and signs were surprisingly severe after ingestion of only 10g. Treatment and unusual features of the case are discussed.

Tegretol no tratamento da epilepsia

O Tegretol (5-carbamil-5H-dibenzo-b,L-azepina) foi usado no tratamento de 68 pacientes com epilepsia; 54 apresentavam epilepsia temporal (42 com crises psicomotoras e 12 com crises complexas), 11 epilepsia focal de projeção não temporal e 3 epilepsia centrencefálica com crises P.M. Resultados satisfatórios foram observados em 82% dos 65 pacientes com epilepsia focal; os 3 pacientes com crises P.M. não foram influenciados pelo tratamento. A ação sobre as manifestações psíquicas que acompanhavam o quadro crítico ou intercrítico das crises ficou bem evidenciada. Os pacientes melhoraram de seus sintomas na grande maioria dos casos, conseguindo adaptar-se melhor no ambiente familiar, profissional e escolar. O efeito sobre as alterações eletrencefalográficas é moderado, e a evolução clínica não acompanha as modificações dos traçados. As doses usadas, em geral de 400 a 600 mg diários, são suficientes para o controle das crises na maioria dos casos e estão muito abaixo dos limites considerados como de segurança. As reações secundárias foram observadas em pequeno número de casos e foram sempre transitórias. O Tegretol representa, em nossa opinião, recurso de valor no trataemnto das epilepsias focais, particularmente nas crises psicomotoras.