Tratamento da epilepsia idiopática canina - quadro clínico após interação medicamentosa / Treatment of canine idiopathic epilepsy - clinical picture after drug interaction

Background: The large number of diseases demand perennial development of the pharmaceutical industry. The drugtesting phase is essential to make them available safely. Awareness of pharmacological properties, adverse effects and drug interactions is required. Drug interactions are common in veterinary medicine and should be avoided. At times, epileptic seizures require polydrug therapy, predisposing patients to drug interactions. The interaction between carbamazepine and phenobarbital reported in the literature is an example. The aim of this paper is to report a clinical picture of drug interaction in the treatment of idiopathic epilepsy. Case: A 1-year-old Border Collie male dog, was admitted at the Veterinary Hospital of the Federal University of Lavras in post-ictal. The tutor reported that a year ago the animal had epileptic seizures and clusters with intervals of 21 to 25 days. Despite the continued use of previously prescribed phenobarbital (7.4 mg/kg, v.o., BID, until new recommendations) and carbamazepine (7.5 mg/kg, v.o., BID, until new recommendations), seizure control was not achieved. The physical examination indicated, tachypnea, ptialism, mydriasis, intense fatigue, and alienation from the environment. The patient did not respond to the threat-reflex test. Blood count, hepatic and renal blood chemistry, serum electrolyte (potassium, sodium, calcium and phosphorus), and phenobarbital dosages were requested. Based on the animal's history, breed characteristics, and alterations in the physical examination associated with normal results in complementary exams, idiopathic epilepsy was diagnosed. After analyzing the case, it was observed that the inefficiency in the control of seizures was possibly due to the drug interaction between phenobarbital and carbamazepine. Carbamazepine and phenobarbital reciprocally reduce their half-lives. To confirm the raised hypothesis, the serum concentration of carbamazepine was gradually reduced through weaning from its dose administered to the patient. Serial dosage of the concentration of phenobarbital in the bloodstream was performed. As a result, the serum phenobarbital, previously dosed at a concentration of 13.3 mg/dL with concomitant administration of carbamazepine, increased to 22 mg/dL 40 days after the beginning of weaning from carbamazepine (T0), and then to 36 mg/dL 100 days after T0. There was an increase in the concentration of phenobarbital in the bloodstream while the serum concentration of carbamazepine declined. The patient spaced out his seizures to every 50 to 60 days with phenobarbital monotherapy at a dose of 6 mg/kg. Discussion: Efficient control of clusters, such as the reduction of seizures by 50%, was only possible due to the meticulous perception of the possible interaction reported in medicine. Carbamazepine and phenobarbital are P450 isoenzyme inducers. The concomitant administration of both drugs potentiated the action of isoenzymes in the hepatic microsomal system, which led to an accelerated metabolic processing of the drugs. After weaning from carbamazepine, that is, reducing the action of carbamazepine on the isoenzymes of the P450 enzyme system, the concentration of phenobarbital normalized at 36 mg/ dL. Such concentration is within the reference range reported in the literature: 25 mg/dL to 35 mg/dL of serum phenobarbital for treatment efficacy. Therefore, the control of convulsive crises was achieved. The increase in the concentration of phenobarbital due only to weaning from carbamazepine, even after decreasing the daily dose of barbiturate prescribed to the animal, contributed to evidence of the interaction of these drugs. It is noted that prior knowledge of pharmacological properties, careful study of the patient's history, and the cooperation of the tutor were essential for the therapeutic success and practice of evidence-based veterinary medicine.

Assessment of carbamazepine acute toxicity in the cockle Cerastoderma edule through chemical, physiological and biochemical tools / Avaliação da toxicidade aguda da carbamazepina no berbigão Cerastoderma edule por meio de ferramentas químicas, fisiológicas e bioquímicas

The cockle Cerastoderma edule was exposed to four concentrations (5, 10, 20 and 70 μg L-¹) of carbamazepine (CBZ). This anticonvulsant was found to alter the mussel behavior of by reducing its clearance rate (CR). Analysis of CBZ accumulation in tissues of C. edule was carried out using HPLC-UV after 48 or 96 hours of exposure. In addition, an overproduction of H2O2 by the bivalves was detected following exposure to CBZ but nitrite levels remained unchanged. Moreover, superoxide dismutase and catalase activities showed a significant increase in relation to their contact with CBZ. The activity of the biotransformation enzyme gluthatione-S-transferase did not change during exposure. Malondialdehyde (MDA) levels indicating cellular damage, increased when bivalves were exposed to 20 and 70 μg l-¹ of carbamazepine for 96 h CBZ. The results also indicate that acetylcholinesterase activity (AChE) was inhibited in all CBZ concentrations during the 48 h exposure period. However, during the 96 h exposure period, AChE was only inhibited at the highest concentration. Further studies are needed now for more exploration of the toxicity of CBZ since it could be bioaccumulable throughout the food web and may affect non-target organisms.(AU)

O berbigão Cerastoderma edule foi exposto a quatro concentrações (5, 10, 20 e 70 μg L-¹) de carbamazepina (CBZ). Este anticonvulsivante alterou o comportamento do mexilhão, reduzindo sua taxa de depuração (CR). A análise do acúmulo de CBZ nos tecidos de C. edule foi realizada por HPLC-UV após 48 ou 96 horas de exposição. Além disso, uma superprodução de H2O2 pelos bivalves foi detectada após a exposição à CBZ, mas os níveis de nitrito permaneceram inalterados. Além disso, as atividades de superóxido dismutase e catalase apresentaram aumento significativo em relação ao contato com CBZ. A atividade da enzima de biotransformação glutationa-S-transferase não se alterou durante a exposição. Os níveis de malondialdeído (MDA), indicando dano celular, aumentaram quando os bivalves foram expostos a 20 e 70 μg l-1 de carbamazepina por 96 h CBZ. Os resultados também indicam que a atividade da acetilcolinesterase (AChE) foi inibida em todas as concentrações de CBZ durante o período de exposição de 48 horas. No entanto, durante o período de exposição de 96 horas, a AChE foi inibida apenas na concentração mais alta. Mais estudos são necessários agora para uma maior exploração da toxicidade da CBZ, uma vez que pode ser bioacumulável em toda a cadeia alimentar e pode afetar organismos não alvo.(AU)

Assessment of carbamazepine acute toxicity in the cockle Cerastoderma edule through chemical, physiological and biochemical tools / Avaliação da toxicidade aguda da carbamazepina no berbigão Cerastoderma edule por meio de ferramentas químicas, fisiológicas e bioquímicas

The cockle Cerastoderma edule was exposed to four concentrations (5, 10, 20 and 70 μg L-¹) of carbamazepine (CBZ). This anticonvulsant was found to alter the mussel behavior of by reducing its clearance rate (CR). Analysis of CBZ accumulation in tissues of C. edule was carried out using HPLC-UV after 48 or 96 hours of exposure. In addition, an overproduction of H2O2 by the bivalves was detected following exposure to CBZ but nitrite levels remained unchanged. Moreover, superoxide dismutase and catalase activities showed a significant increase in relation to their contact with CBZ. The activity of the biotransformation enzyme gluthatione-S-transferase did not change during exposure. Malondialdehyde (MDA) levels indicating cellular damage, increased when bivalves were exposed to 20 and 70 μg l-¹ of carbamazepine for 96 h CBZ. The results also indicate that acetylcholinesterase activity (AChE) was inhibited in all CBZ concentrations during the 48 h exposure period. However, during the 96 h exposure period, AChE was only inhibited at the highest concentration. Further studies are needed now for more exploration of the toxicity of CBZ since it could be bioaccumulable throughout the food web and may affect non-target organisms.

O berbigão Cerastoderma edule foi exposto a quatro concentrações (5, 10, 20 e 70 μg L-¹) de carbamazepina (CBZ). Este anticonvulsivante alterou o comportamento do mexilhão, reduzindo sua taxa de depuração (CR). A análise do acúmulo de CBZ nos tecidos de C. edule foi realizada por HPLC-UV após 48 ou 96 horas de exposição. Além disso, uma superprodução de H2O2 pelos bivalves foi detectada após a exposição à CBZ, mas os níveis de nitrito permaneceram inalterados. Além disso, as atividades de superóxido dismutase e catalase apresentaram aumento significativo em relação ao contato com CBZ. A atividade da enzima de biotransformação glutationa-S-transferase não se alterou durante a exposição. Os níveis de malondialdeído (MDA), indicando dano celular, aumentaram quando os bivalves foram expostos a 20 e 70 μg l-1 de carbamazepina por 96 h CBZ. Os resultados também indicam que a atividade da acetilcolinesterase (AChE) foi inibida em todas as concentrações de CBZ durante o período de exposição de 48 horas. No entanto, durante o período de exposição de 96 horas, a AChE foi inibida apenas na concentração mais alta. Mais estudos são necessários agora para uma maior exploração da toxicidade da CBZ, uma vez que pode ser bioacumulável em toda a cadeia alimentar e pode afetar organismos não alvo.

Epilepsia no período gravídico-puerperal / Epilepsy in puerperal-pregnancy period

A epilepsia, doença cerebral caracterizada pela predisposição à geração de crises epilépticas, representa a patologia neurológica grave mais frequente na gravidez. Quando não acompanhada corretamente, possui um acentuado nível de morbimortalidade materno-fetal, sendo especialmente relacionada a riscos de convulsão materna na gestação e malformações fetais. Este artigo discute o acompanhamento da gestante epiléptica, trazendo recomendações de cuidados no período pré-concepcional, manejo durante o pré-natal, condução do trabalho de parto, peculiaridades no puerpério e tratamento de crises convulsivas, quando necessário. Serão abordados tanto aspectos de tratamento farmacológico quanto de monitoramento e orientações gerais, com o objetivo de contribuir para um suporte mais abrangente e adequado a esse grupo mais vulnerável de pacientes sob o cuidado do médico ginecologista-obstetra e neurologista.(AU)

Epilepsy, which is a brain disease defined for a greater predisposition for epileptic crisis, represents the most frequent neurological pathology during pregnancy. Without proper monitoring it is related to high morbidity and mortality to both mother and baby, especially due to the risks of mother seizure during pregnancy and fetus malformation. This article discusses about health care giving and follow-up for the epileptic pregnant women, pointing recommendations for preconception care, prenatal management, labor conduct, peculiarities in puerperium and treatment of convulsive crisis when needed. There will be approached pharmacological and non-pharmacological aspects, such as follow up exams and general orientations, having as a goal to contribute to an more abrangent and proper support of this more vulnerable group of patients under the care responsibility of obstetrician-gynecologist ad neurologist doctors.(AU)

Anatomical, radiological and clinical features of mesial temporal lobe epilepsy: two illustrated cases reports / Aspectos anatômicos, radiológicos e clínicos da epilepsia do lobo temporal mesial: relato ilustrado de dois casos

Mesial temporal lobe epilepsy is the most commom form of focal epilepsy in adults. Its clinical features include focal seizure, dysmnestic symptoms ­ such as déjà vu or jamais vu ­ and autonomic or psychic aura. We reported two cases of mesial temporal lobe epilepsy with similar clinical features, but with entirely different etiologies. Mesial temporal sclerosis contributes up to 70% of all mesial temporal lobe epilepsy cases and MRI usually shows reduced hippocampal volume and increased signal intensity on T2-weighted imaging. Incomplete hippocampal inversion has uncertain relation with epilepsy and is characterized by an atypical verticalized and medially positioned anatomical pattern of the hippocampus and also a deep collateral sulcus.

A epilepsia do lobo temporal mesial é a forma mais comum de epilepsia focal em adultos. Suas características clínicas incluem crises focais, sintomas dismnésicos - como déjà vu ou jamais vu - e aura autonômica ou psíquica. Relatamos dois casos de pacientes com epilepsia do lobo temporal mesial com manifestações clínicas semelhantes, mas com etiologias completamente diferentes. A esclerose mesial temporal contribui com até 70% de todos os casos de epilepsia do lobo temporal mesial e, geralmente, na ressonância magnética, apresenta atrofia do hipocampo e hipersinal na imagem ponderada em T2. A rotação incompleta do hipocampo possui uma relação incerta com a epilepsia e é caracterizada por alteração da estrutura interna do hipocampo, com um sulco colateral verticalizado e profundo.

Pain management in children with erythromelalgia: case report / Tratamento da dor em criança com eritromelalgia: relato de caso

Abstract Erythromelalgia is a neuropathic pain syndrome due to an autosomal dominant gene, characterized by erythema, increased skin temperature and burning pain in hands and feet, whose treatment is often unsatisfactory. In this paper, we report a case of a 9 years old female patient whose first episode of burning pain, erythema and edema of the hands, without triggering factors, had instant relief after immersion in cold water. She presented with systemic arterial hypertension and had seizures. The patient was treated with gabapentin (150 mg.8 h−1) and amitriptyline (12.5 mg) orally, intravenous lidocaine infusion (120 mg), without relieving pain complaints. Due to the lack of response to the proposed treatment, it was decided to gradually reduce these medications and to introduce carbamazepine (200 mg) orally and, after 4 days of treatment, there was complete relief of the manifestations.

Resumo Eritromelalgia é uma síndrome dolorosa neuropática decorrente de gene autossômico dominante, caracterizada por eritema, aumento da temperatura da pele e dor em queimação, em mãos e pés, e o tratamento é muitas vezes insatisfatório. Neste caso, está o relato de uma paciente do sexo feminino, com nove anos e primeiro episódio de dor em queimação, eritema e edema em mãos, sem fatores desencadeantes, com alívio instantâneo após imersão em água fria. Apresentava hipertensão arterial sistêmica e teve crises convulsivas. Foi tratada com gabapentina (150 mg.8 h-1) e amitriptilina (12,5 mg) via oral, lidocaína (120 mg) venosa em infusão, sem alívio das queixas álgicas. Devido à ausência de resposta ao tratamento proposto, decidiu-se redução gradativa dessas medicações e introdução de carbamazepina (200 mg) via oral e após quatro dias de tratamento houve alívio completo das manifestações.

Carbamazepine adverse drug reactions.

INTRODUCTION: Carbamazepine (CBZ) is used for the treatment of epilepsy and other neurological and psychiatric disorders. The occurrence of adverse reactions (ADRs) to CBZ can negatively impact the quality of life of patients, as well as increase health-care costs. Thus, knowledge of CBZ-induced ADRs is important to achieve safer treatment outcomes. Areas covered: This review describes the clinical features, known mechanisms, and clinical management of the main CBZ-induced ADRs. In addition, pharmacogenetic studies focused on ADRs induced by CBZ are cited. Expert commentary: CBZ-induced ADRs are well known in the literature. The metabolite CBZ-10,11-epoxide plays an important role in the mechanism that underlies the ADRs induced by CBZ. Several factors should be considered for a safer use of CBZ, such as monotherapy prescription when possible, an adequate dose titration, knowledge of previous ADRs in the patient, and routine monitoring of CBZ plasma concentrations in symptomatic patients. Pharmacogenetics is a potential tool for CBZ therapy improvement, and the design of multicenter studies focused on the identification of biomarkers for CBZ-induced ADRs could provide useful information for a safer CBZ therapy.

Síndrome de sensibilidad a fármacos con eosinofilia y síntomas sistémicos debido a la carbamazepina: Caso pediátrico / Drug reaction with eosinophilia and systemic symptoms due to carbamazepine: Pediatric case

Entre las reacciones medicamentosas graves en la piel, se encuentran el síndrome de Stevens-Johnson, la necrólisis epidérmica tóxica y el síndrome de sensibilidad a fármacos con eosinofilia y síntomas sistémicos (drug reaction with eosinophilia and systemic symptoms; DRESS, por sus siglas en inglés), que son poco comunes en la población pediátrica (incidencia: 1/1000-10 000 niños), sin embargo, tienen mal pronóstico. El síndrome de sensibilidad a fármacos con eosinofilia y síntomas sistémicos consiste en erupciones cutáneas, alteraciones hematológicas, linfadenopatía y afectación de órganos. Se presenta el caso de un paciente masculino de 12 años que desarrolló esta patología después de iniciar el tratamiento anticonvulsivo con carbamazepina. Se considera que es importante que el personal de la salud tenga conocimiento de esta enfermedad para que sea incluida entre los diagnósticos diferenciales de pacientes con afecciones similares, ya que este síndrome es potencialmente mortal.

Severe skin reactions include Stevens-Johnson Syndrome, toxic epidermal necrolysis and Drug reaction with Eosinophilia and Systemic Symptoms (DRESS) syndrome, which are uncommon in the pediatric population (incidence 1/1000-10 000 children), but they have bad prognosis. Drug-sensitive Syndrome with eosinophilia and systemic symptoms consists in rash, hematological abnormalities, lymphadenopathy and organ involvement. We report the case of a 12-year-old male patient who developed this pathology after initiating anticonvulsant therapy with carbamazepine. We consider that it is important to be aware of this disease and to include it among the differential diagnoses in patients with similar conditions because this syndrome is life-threatening.

[Drug reaction with eosinophilia and systemic symptoms due to carbamazepine. Pediatric case]. / Síndrome de sensibilidad a fármacos con eosinofilia y síntomas sistémicos debido a la carbamazepina. Caso pediátrico.

Severe skin reactions include Stevens-Johnson Syndrome, toxic epidermal necrolysis and Drug reaction with Eosinophilia and Systemic Symptoms (DRESS) syndrome, which are uncommon in the pediatric population (incidence 1/1000- 10 000 children), but they have bad prognosis. Drug-sensitive Syndrome with eosinophilia and systemic symptoms consists in rash, hematological abnormalities, lymphadenopathy and organ involvement. We report the case of a 12-year-old male patient who developed this pathology after initiating anticonvulsant therapy with carbamazepine. We consider that it is important to be aware of this disease and to include it among the differential diagnoses in patients with similar conditions because this syndrome is life-threatening.

Entre las reacciones medicamentosas graves en la piel, se encuentran el síndrome de Stevens-Johnson, la necrólisis epidérmica tóxica y el síndrome de sensibilidad a fármacos con eosinofilia y síntomas sistémicos (drug reaction with eosinophilia and systemic symptoms; DRESS, por sus siglas en inglés), que son poco comunes en la población pediátrica (incidencia: 1/1000- 10 000 niños), sin embargo, tienen mal pronóstico. El síndrome de sensibilidad a fármacos con eosinofilia y síntomas sistémicos consiste en erupciones cutáneas, alteraciones hematológicas, linfadenopatía y afectación de órganos. Se presenta el caso de un paciente masculino de 12 años que desarrolló esta patología después de iniciar el tratamiento anticonvulsivo con carbamazepina. Se considera que es importante que el personal de la salud tenga conocimiento de esta enfermedad para que sea incluida entre los diagnósticos diferenciales de pacientes con afecciones similares, ya que este síndrome es potencialmente mortal.

Carbamazepine-loaded solid lipid nanoparticles and nanostructured lipid carriers: Physicochemical characterization and in vitro/in vivo evaluation.

Solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) represent promising alternatives for drug delivery to the central nervous system. In the present work, four different nanoformulations of the antiepileptic drug Carbamazepine (CBZ) were designed and prepared by the homogenization/ultrasonication method, with encapsulation efficiencies ranging from 82.8 to 93.8%. The formulations remained stable at 4 °C for at least 3 months. Physicochemical and microscopic characterization were performed by photon correlation spectroscopy (PCS), transmission electron microscopy (TEM), atomic force microscopy (AFM); thermal properties by differential scanning calorimetry (DSC), thermogravimetry (TGA) and X-ray diffraction analysis (XRD). The results indicated the presence of spherical shape nanoparticles with a mean particle diameter around 160 nm in a narrow size distribution; the entrapped CBZ displayed an amorphous state. The in vitro release profile of CBZ fitted into a Baker-Lonsdale model for spherical matrices and almost the 100% of the encapsulated drug was released in a controlled manner during the first 24 h. The apparent permeability of CBZ-loaded nanoparticles through a cell monolayer model was similar to that of the free drug. In vivo experiments in a mice model of seizure suggested protection by CBZ-NLC against seizures for at least 2 h after intraperitoneal administration. The developed CBZ-loaded lipid nanocarriers displayed optimal characteristics of size, shape and drug release and possibly represent a promising tool to improve the treatment of refractory epilepsy linked to efflux transporters upregulation.

PAMAM dendrimers as a carbamazepine delivery system for neurodegenerative diseases: A biophysical and nanotoxicological characterization.

Carbamazepine (CBZ) is an antiepileptic drug, which also could be used in the treatment of neurodegenerative diseases, such as the Alzheimer's disease. However, its use has been limited due to its low solubility, inefficient pharmacokinetic profiles, and multiple side effects. PAMAM dendrimers, ethylenediamine core, generation 4.0 (amine terminal groups) and 4.5 (carboxylate terminal groups) (DG4.0 and DG4.5 respectively) are polymers that can increase drug solubility through complexation. Thus, the aim of this work was to obtain and characterize complexes between CBZ and dendrimers. Both DG4.0 and DG4.5 allowed the incorporation of ∼20 molecules of CBZ per dendrimer, into their hydrophobic pockets. DG4.0-CBZ and DG4.5-CBZ complexes were found to be stable for 90 days at 37 °C and resistant to a lyophilization process, presenting controlled drug release. Also, the complexes nanotoxicity was tested ex vivo (human red blood cells), in vitro (N2a cell line), and in vivo (zebrafish). No hemolytic effect was observed in the ex vivo model. As regards in vitro toxicity, the DG4.5-CBZ complexes significantly reduced the toxicity caused by the free drug. Moreover, the DG4.5-CBZ did not cause neurotoxicity or cardiotoxicity in zebrafish larvae. In conclusion, a stable and biocompatible drug delivery system based on the DG4.5 capable of complex the CBZ has been developed. This achievement highlights the advantages of using negatively charged dendrimers for nanomedicine.

Analysis of unbound plasma concentration of oxcarbazepine and the 10-hydroxycarbazepine enantiomers by liquid chromatography with tandem mass spectrometry in healthy volunteers.

This study describes the development and validation of a method for the analysis of unbound plasma concentrations of oxcarbazepine (OXC) and of the enantiomers of its active metabolite 10-hydroxycarbazepine (MHD) [S-(+)- and R-(-)-MHD] using liquid chromatography with tandem mass spectrometry (LC-MS/MS). Additionally, the free fraction of the drug is described in healthy volunteers (n=12) after the oral administration of 300mg OXC/12h for 5days. Plasma aliquots of 200µL were submitted to ultrafiltration procedure and 50µL of the ultrafiltrate were extracted with a mixture of tert-butyl methyl ether:dichloromethane (2:1, v/v). OXC and the MHD enantiomers were separated on a OD-H chiral phase column. The method was linear in the range of 4.0-2.0µg/mL for OXC and of 20.0-6.0µg/mL plasma for the MHD enantiomers. The limit of quantification was 4ng for OXC and 20ng for each MHD enantiomer/mL plasma. The intra- and inter-day precision and inaccuracy were less than 15%. The free fraction at the time of peak plasma concentration of OXC was 0.27 for OXC, 0.37 for S-(+)-MHD and 0.42 for R-(-)-MHD. Enantioselectivity in the free fraction of MHD was observed, with a higher proportion of R-(-)-MHD compared to S-(+)-MHD.

Polirradiculoneuropatia periférica desmielinizante associada ao uso de carbamazepina em cão: relato de caso / Demyelinating peripheral polyradiculoneuropathy associated with the use of carbamazepine in dog: case report

Diversos fármacos são utilizados no tratamento da epilepsia e, assim como outros medicamentos, podem induzir a ocorrência de efeitos adversos, alguns tão graves que geram a necessidade de descontinuidade e substituição da terapia. A carbamazepina pode levar a alterações nos sistemas cardiovascular, respiratório e neurológico, sendo descritos na literatura casos de indução de miastenia gravis como distúrbio neuromuscular. Este estudo relata o caso de um cão que desenvolveu polirradiculoneuropatia desmielinizante, tendo como provável desencadeante a terapia com carbamazepina. O paciente apresentou tetraplegia, ausência de reflexos espinhais nos quatro membros, fraqueza cervical, diminuição do reflexo palpebral bilateral e esforço respiratório. A eletroneuromiografia demonstrou sinais de desmielinização. Este, portanto, é o primeiro relato de associação entre carbamazepina e polirradiculoneuropatia desmielinizante em cão.(AU)

Different drugs are used in the treatment of epilepsy and, like other drugs, may induce the occurrence of adverse effects, some of them so severe that the drug must be discontinued and replaced. Carbamazepine may lead to changes in the cardiovascular, respiratory, and neurological systems, and cases of induction of myasthenia gravis as a neuromuscular disorder have been described in the literature. This paper reports the case of a dog that developed demyelinating polyradiculoneuropathy, probably triggered by carbamazepine. The patient presented tetraplegia, absence of spinal reflexes in the four limbs, cervical weakness, decreased bilateral eyelid reflex and respiratory effort. Electroneuromyography showed signs of demyelination. This, therefore, is the first report of association between carbamazepine and demyelinating polyradiculoneuropathy in dogs.(AU)

Polirradiculoneuropatia periférica desmielinizante associada ao uso de carbamazepina em cão: relato de caso / Demyelinating peripheral polyradiculoneuropathy associated with the use of carbamazepine in dog: case report

Diversos fármacos são utilizados no tratamento da epilepsia e, assim como outros medicamentos, podem induzir a ocorrência de efeitos adversos, alguns tão graves que geram a necessidade de descontinuidade e substituição da terapia. A carbamazepina pode levar a alterações nos sistemas cardiovascular, respiratório e neurológico, sendo descritos na literatura casos de indução de miastenia gravis como distúrbio neuromuscular. Este estudo relata o caso de um cão que desenvolveu polirradiculoneuropatia desmielinizante, tendo como provável desencadeante a terapia com carbamazepina. O paciente apresentou tetraplegia, ausência de reflexos espinhais nos quatro membros, fraqueza cervical, diminuição do reflexo palpebral bilateral e esforço respiratório. A eletroneuromiografia demonstrou sinais de desmielinização. Este, portanto, é o primeiro relato de associação entre carbamazepina e polirradiculoneuropatia desmielinizante em cão.(AU)

Different drugs are used in the treatment of epilepsy and, like other drugs, may induce the occurrence of adverse effects, some of them so severe that the drug must be discontinued and replaced. Carbamazepine may lead to changes in the cardiovascular, respiratory, and neurological systems, and cases of induction of myasthenia gravis as a neuromuscular disorder have been described in the literature. This paper reports the case of a dog that developed demyelinating polyradiculoneuropathy, probably triggered by carbamazepine. The patient presented tetraplegia, absence of spinal reflexes in the four limbs, cervical weakness, decreased bilateral eyelid reflex and respiratory effort. Electroneuromyography showed signs of demyelination. This, therefore, is the first report of association between carbamazepine and demyelinating polyradiculoneuropathy in dogs.(AU)

Population pharmacokinetics of oxcarbazepine and its metabolite 10-hydroxycarbazepine in healthy subjects.

Oxcarbazepine is indicated for the treatment of partial or generalised tonic-clonic seizures. Most of the absorbed oxcarbazepine is converted into its active metabolite, 10-hydroxycarbazepine (MHD), which can exist as R-(-)- and S-(+)-MHD enantiomers. Here we describe the influence of the P-glycoprotein (P-gp) inhibitor verapamil, on the disposition of oxcarbazepine and MHD enantiomers, both of which are P-gp substrates. Healthy subjects (n=12) were randomised to oxcarbazepine or oxcarbazepine combined with verapamil at doses of 300mg b.i.d. and 80mg t.i.d., respectively. Blood samples (n=185) were collected over a period of 12h post oxcarbazepine dose. An integrated PK model was developed using nonlinear mixed effects modelling using a meta-analytical approach. The pharmacokinetics of oxcarbazepine was described by a two-compartment model with absorption transit compartments and first-order elimination. The concentration-time profiles of both MHD enantiomers were characterised by a one-compartment distribution model. Clearance estimates (95% CI) were 84.9L/h (69.5-100.3) for oxcarbazepine and 2.0L/h (1.9-2.1) for both MHD enantiomers. The volume of distribution was much larger for oxcarbazepine (131L (97-165)) as compared to R-(-)- and S-(+)-MHD (23.6L (14.4-32.8) vs. 31.7L (22.5-40.9), respectively). Co-administration of verapamil resulted in a modest increase of the apparent bioavailability of oxcarbazepine by 12% (10-28), but did not affect parent or metabolite clearances. Despite the evidence of comparable systemic levels of OXC and MHD following administration of verapamil, differences in brain exposure to both moieties cannot be excluded after P-glycoprotein inhibition.

[Skin reaction to carbamazepine or DRESS syndrome: a case presentation]. / Reacción cutánea al tratamiento con carbamazepina o síndrome DRESS: presentación de un caso.

Carbamazepine is a frequently used drug that can produce adverse reactions like vertigo, somnolence and severe skin reactions like Drug Rash with Eosinophilia and Systemic Symptoms Syndrome (DRESS Syndrome). This syndrome is characterized by a late-appearing, slow-progressing cutaneous eruption accompanied by atypical lymphocytes, eosinophilia, and systemic symptoms such as fever, lymphadenopathy, hepatic compromise, and renal dysfunction that can be severe enough to cause death. We present a case that aims to highlight the importance of an early diagnosis of DRESS syndrome to adjust therapy and improve survival. The patient is a female patient prescribed carbamazepine for trigeminal neuralgia who presented with skin lesions, which were initially attributed to a hypersensitivity reaction. The lesions worsened in spite of treatment and systemic symptoms ensued. A diagnosis of DRESS syndrome was proposed and steroid treatment was initiated with rapid improvement.

La carbamazepina es un medicamento de empleo habitual que puede producir efectos secundarios y en algunos casos reacciones adversas como vértigos, somnolencia y reacciones cutáneas que pueden ser severas como el síndrome DRESS (Drug Rash with Eosinophilia and Systemic Symptoms). Se caracteriza por erupción cutánea tardía y lenta progresión, linfocitos atípicos con eosinofilia y síntomas sistémicos como fiebre, adenopatías, hepatopatía y trastornos renales, pudiendo llegar a la muerte del paciente. Se presenta un caso para destacar la importancia del diagnóstico temprano del síndrome DRESS, que garantice un manejo adecuado para la supervivencia del paciente. Es una paciente bajo tratamiento con carbamazepina para neuralgia del trigémino, que al tiempo comienza con lesiones cutáneas que se interpretan como reacción de hipersensibilidad. Al no mejorar con tratamiento inicial y empeorar el cuadro cutáneo, acompañándose de síntomas generales, se realizan análisis complementarios y se plantea el diagnóstico de síndrome DRESS que se resuelve definitivamente con esteroides.

Epileptic spasms without hypsarrhythmia in infancy and childhood: tonic spasms as a seizure type.

Epileptic spasms were defined by the International League Against Epilepsy Task Force on Classification and Terminology in 2001 as a specific seizure type. Epileptic spasms without hypsarrhythmia have been described in some series of patients, occurring either in infancy or childhood. More prolonged epileptic spasms without hypsarrhythmia were previously defined as a different seizure type, and referred to as "tonic spasm seizures". Here, we present a 5-year-old boy who started having epileptic spasms without hypsarrhythmia at 8 months of age, effectively treated with oxcarbazepine. With the withdrawal of medication, epileptic spasms returned. Video-EEG monitoring revealed high-voltage slow waves superimposed by low-voltage fast activity, followed by an electrodecremental phase and a burst of asymmetric fast activity, time-locked to clinical tonic spasm seizures. Brain MRI showed left temporal atrophy with temporal pole grey/white matter junction blurring and ictal PET-CT showed left basal frontal hypermetabolism. Seizures were refractory to several AEDs and vigabatrin was introduced with seizure cessation. Despite efforts to classify epileptic spasms, these are still considered as part of the group of unknown seizure types. In some cases, a focal origin has been suggested, leading to the term "periodic spasms" and "focal spasms". In this case, epileptic spasms without hypsarrhythmia, associated with tonic spasms, may be a variant of focal spasms and might be considered as an epileptic syndrome. [Published with video sequence].