Drug utilization profile in adult patients with refractory epilepsy at a tertiary referral center / Perfil de utilizacao de farmacos por pacientes adultos com epilepsia refrataria em um centro terciario de referencia

Objective To evaluate the utilization profile of antiepileptic drugs in a population of adult patients with refractory epilepsy attending a tertiary center. Method Descriptive analyses of data were obtained from the medical records of 112 patients. Other clinical and demographic characteristics were also registered. Results Polytherapies with ≥3 antiepileptic drugs were prescribed to 60.7% of patients. Of the old agents, carbamazepine and clobazam were the most commonly prescribed (72.3% and 58.9% of the patients, respectively). Among the new agents, lamotrigine was the most commonly prescribed (36.6% of the patients). At least one old agent was identified in 103 out of the 104 polytherapies, while at least one new agent was prescribed to 70.5% of the population. The most prevalent combination was carbamazepine + clobazam + lamotrigine. The mean AED load found was 3.3 (range 0.4–7.7). Conclusion The pattern of use of individual drugs, although consistent with current treatment guidelines, is strongly influenced by the public health system. .

Objetivo Avaliar o perfil de utilização de fármacos antiepilépticos em uma população de pacientes adultos com epilepsia refratária atendidos em um centro terciário. Método Análises descritivas dos dados obtidos dos registros médicos de 112 pacientes. Também foram consideradas as características clínicas e demográficas. Resultados Foram prescritas politerapias com ≥3 antiepilépticos a 60,7% dos pacientes. Em relação aos fármacos de primeira geração, carbamazepina e clobazam foram os mais frequentemente prescritos (a 72,3% e 58,9% dos pacientes, respectivamente). Dentre os novos antiepilépticos, a lamotrigina foi o mais prescrito (36,6% dos pacientes). Ao menos um antiepiléptico de primeira geração foi encontrado em 103 das 104 politerapias; ao menos um novo antiepiléptico foi prescrito a 70,5% da população. A combinação mais prevalente foi carbamazepina+clobazan+lamotrigina. A carga média de antiepilépticos foi 3.3 (0.4 a 7.7). Conclusão O padrão de utilização de antiepilépticos, embora concordante com guias atuais, é fortemente influenciado pelo sistema público de saúde. .

Lamotrigine therapeutic drug monitoring in a tertiary epilepsy centre / Monitorização terapêutica da lamotrigina em um centro terciário de epilepsia

Objective: to review the experience with lamotrigine therapeutic drug monitoring in a tertiary epilepsy centre aiming to characterize the plasma concentrations profile. Methods: inclusion of adults and children to whom lamotrigine concentrations were requested from October 2008 to April 2010. A chromatographic method was validated to determine lamotrigine concentrations. Reference range adopted (plasma): 2.5-15.0 mg/L. Results: 115 patients were included (86 adults, 29 children). Mean±standard deviation lamotrigine dosages for adults and children were statistically different (5.1±2.0 versus 7.4±3.4 mg/kg/day respectively, p<0.0001), so as lamotrigine concentrations (5.13±4.0 versus 9.0±5.6 mg/L respectively, p=0.0006). Approximately 68% of all quantifications were within the reference range. From the 29 quantifications below 2.5 mg/L, 27 corresponded to lamotrigine+enzyme inducers therapies. There was no correlation between lamotrigine concentrations and dosages neither for pediatric nor for adult groups. Patients on monotherapy had lamotrigine concentrations significantly higher than those on lamotrigine+inducers therapies (p<0.001), and patients on lamotrigine+valproic acid therapy had lamotrigine concentrations higher than those on lamotrigine+inducers (p<0.001). There was no significant difference among mean dosages according to different comedications. Conclusion: our observations about the influence of polytherapies on lamotrigine pharmacokinetics confirm the relevance of quantifying this antiepileptic drug plasma concentrations in the process of treatment optimization...

Objetivo: revisar a experiência de um centro terciário de epilepsia com a monitorização terapêutica da lamotrigina objetivando caracterizar o perfil de concentrações plasmáticas encontradas. Métodos: inclusão de todos adultos e crianças para os quais solicitou-se quantificação plasmáticas de lamotrigina de Outubro/2008 a Abril/2010. Um método cromatográfico foi validado para determinar as concentrações de lamotrigina. Intervalo de referência adotado (plasma): 2.5-15.0 mg/L. Resultados: 115 pacientes foram incluídos (86 adultos, 29 crianças). Média±desvio-padrão das doses de lamotrigina para adultos e crianças foram significativamente diferentes (5.1±2.0 versus 7.4±3.4 mg/kg/dia respectivamente, p<0.0001), assim como as concentrações (5.13±4.0 versus 9.0±5.6 mg/L, p=0.0006). Aproximadamente 68% das quantificações estavam dentro do intervalo de referência. Das 29 quantificações abaixo de 2.5 mg/L, 27 correspondiam a associações lamotrigina+indutores enzimáticos. Não houve correlação entre concentrações e doses de lamotrigina. Pacientes em monoterapia tiveram concentrações de lamotrigina significativamente maiores do que pacientes utilizando lamotrigina+indutores enzimáticos (p<0.001); pacientes em uso de lamotrigina+ácido valproico apresentaram concentrações maiores comparativamente àqueles em uso de lamotrigina+indutores (p<0.001). Não houve diferença significativa entre doses médias de acordo com diferentes comedicações. Conclusão: a influência de politerapias sobre a farmacocinética da lamotrigina confirma a relevância dese quantificar as concentrações plasmáticas deste antiepilético no processo de otimização terapêutica...

Drug utilization profile in adult patients with refractory epilepsy at a tertiary referral center.

OBJECTIVE: To evaluate the utilization profile of antiepileptic drugs in a population of adult patients with refractory epilepsy attending a tertiary center. METHOD: Descriptive analyses of data were obtained from the medical records of 112 patients. Other clinical and demographic characteristics were also registered. RESULTS: Polytherapies with ≥3 antiepileptic drugs were prescribed to 60.7% of patients. Of the old agents, carbamazepine and clobazam were the most commonly prescribed (72.3% and 58.9% of the patients, respectively). Among the new agents, lamotrigine was the most commonly prescribed (36.6% of the patients). At least one old agent was identified in 103 out of the 104 polytherapies, while at least one new agent was prescribed to 70.5% of the population. The most prevalent combination was carbamazepine + clobazam + lamotrigine. The mean AED load found was 3.3 (range 0.4-7.7). CONCLUSION: The pattern of use of individual drugs, although consistent with current treatment guidelines, is strongly influenced by the public health system.