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Valproic Acid (valproic + acid)
Kinds of Valproic Acid Selected AbstractsValproic Acid,induced Hair-texture Changes in a White WomanEPILEPSIA, Issue 2 2007Ingeborg Wilting No abstract is available for this article. [source] Absence Seizures Aggravated by Valproic AcidEPILEPSIA, Issue 7 2001Tally Lerman-Sagie Summary: ,Purpose: To report on pediatric patients with absence epilepsy who experienced absence seizure aggravation while receiving valproic acid (VPA). Methods: The charts of all children from four pediatric epilepsy clinics receiving VPA for absence epilepsy were reviewed. Patients were evaluated and followed up between 1994 and 2000. Results: Eight cases (six boys) of absence seizure aggravation were detected. Mean age at seizure onset was 5.8 years (range, 3,12 years). Six patients had simple absence seizures, one had myoclonic absences, and one had absences with automatisms. The electroencephalogram in all cases depicted generalized 3-Hz spike-and-wave activities. All eight patients experienced an increase in the frequency of absence seizures within days of VPA introduction. Dose increments resulted in further seizure aggravation. Serum levels of VPA were within therapeutic range in all patients. No case was attributed to VPA-induced encephalopathy. All patients improved on VPA discontinuation. In five children, VPA was reintroduced, resulting in further seizure aggravation. Conclusions: VPA can occasionally provoke absence seizure aggravation in patients with absence epilepsy. [source] Reply to Valproic Acid for the Treatment of Myeloid MalignanciesCANCER, Issue 10 2008Andrea Kuendgen MD No abstract is available for this article. [source] Valproic acid-induced congenital malformations: Clinical and experimental observationsCONGENITAL ANOMALIES, Issue 4 2000R. Padmanabhan ABSTRACT With a large number of epileptic women being in the childbearing age group, complications of pregnancy in epileptic patients are of concern. Epileptic women are treated with antiepileptic drugs (AED) whether they are pregnant or not. Contrary to prevailing opinion, recent data suggest that epilepsy per se contributes significantly to birth defects possibly because of the same genetic susceptibility that predisposes to epilepsy. Many of these defects closely resemble those attributed to exposure to AED. The syndromes attributed to various AED also considerably overlap with each other. Valproic acid (VPA) induces several minor and major malformations. The relative risk for spina bifida in VPA exposed pregnancies is nearly 20 times higher than that for the general population and about 10 times higher than that attributed to other anticonvulsants. Fetuses of experimental animals treated with VPA during pregnancy exhibit exencephaly unlike the human offspring in whom VPA induces spina bifida. The cranial and spinal malformations observed in humans and laboratory animals indicate that VPA has a preferentially deleterious effect on the neural crest. Several AEDs including VPA tend to lower maternal plasma folate levels. In view of the beneficial effects of periconceptional folate supplementation in prevention of neural tube defects (NTD), future research should be directed at the role of folate in the possible alleviation of VPA-induced NTD. It is also necessary to continue prospective studies to monitor the old and new AED prescribed and to evaluate the role of interactions between drugs used in combinations. [source] Clinical picture of EPM1-Unverricht-Lundborg diseaseEPILEPSIA, Issue 4 2008Reetta Kälviäinen Summary Unverricht-Lundborg disease (ULD), progressive myoclonic epilepsy type 1 (EPM1, OMIM254800), is an autosomal recessively inherited neurodegenerative disorder characterized by age of onset from 6 to 16 years, stimulus-sensitive myoclonus, and tonic,clonic epileptic seizures. Some years after the onset ataxia, incoordination, intentional tremor, and dysarthria develop. Individuals with EPM1 are mentally alert but show emotional lability, depression, and mild decline in intellectual performance over time. The diagnosis of EPM1 can be confirmed by identifying disease-causing mutations in a cysteine protease inhibitor cystatin B (CSTB) gene. Symptomatic pharmacologic and rehabilitative management, including psychosocial support, are the mainstay of EPM1 patients' care. Valproic acid, the first drug of choice, diminishes myoclonus and the frequency of generalized seizures. Clonazepam and high-dose piracetam are used to treat myoclonus, whereas levetiracetam seems to be effective for both myoclonus and generalized seizures. There are a number of agents that aggravate clinical course of EPM1 such as phenytoin aggravating the associated neurologic symptoms or even accelerating cerebellar degeneration. Sodium channel blockers (carbamazepine, oxcarbazepine) and GABAergic drugs (tiagabine, vigabatrin) as well as gabapentin and pregabalin may aggravate myoclonus and myoclonic seizures. EPM1 patients need lifelong clinical follow-up, including evaluation of the drug-treatment and comprehensive rehabilitation. [source] Effects of Antiepileptic Drugs on Refractory Seizures in the Intact Immature Corticohippocampal Formation In VitroEPILEPSIA, Issue 11 2003Pascale Paule Quilichini Summary:,Purpose: We developed a new in vitro preparation of immature rats, in which intact corticohippocampal formations (CHFs) depleted in magnesium ions become progressively epileptic. The better to characterize this model, we examined the effects of 14 antiepileptic drugs (AEDs) currently used in clinical practice. Methods: Recurrent ictal-like seizures (ILEs, four per hour) were generated in intact CHFs of P7,8 rats, and extracellular recordings were performed in the hippocampus and neocortex. AEDs were applied at clinically relevant concentrations (at least two), during 30 min after the third ILE. Their ability to prevent or to delay the next ILE was examined. Results: Valproic acid and benzodiazepines (clobazam and midazolam) but also phenobarbital and levetiracetam prevent the occurrence of seizures. In contrast, usual concentrations of carbamazepine (CBZ), phenytoin, vigabatrin, tiagabine, gabapentin, lamotrigine (LTG), topiramate, felbamate, and ethosuximide did not suppress ILEs. In addition, LTG and CBZ aggravate seizures in one third of the cases. Conclusions: This intact in vitro preparation in immature animals appears to be quite resistant to most AEDs. Blockade of seizures was achieved with drugs acting mainly at the ,-aminobutyric acid (GABA)A -receptor site but not with those that increase the amount of GABA. Drugs with a broad spectrum of activity are efficient but not those preferentially used in partial seizures or absences. We suggest that this preparation may correspond to a model of epilepsy with generalized convulsive seizures and could be helpful to develop new AEDs for refractory infantile epilepsies. [source] Low Serum Biotinidase Activity in Children with Valproic Acid MonotherapyEPILEPSIA, Issue 10 2001K. H. Schulpis Summary: ,Purpose: Valproic acid (VPA) is an effective antiepileptic drug (AED), which is associated with dose-related adverse reactions such as skin rash, hair loss (alopecia), etc. Profound as well as partial biotinidase deficiency causes dermatologic manifestations similar these. Therefore, it was of interest to evaluate serum biotinidase activity in patients receiving VPA monotherapy. Methods: Seventy-five patients with seizures, mean age, 8.6 years (±1.9 years) were divided into three groups. Group A (n = 25) was treated with VPA 28.7 ± 8.5 mg/kg/24 h, group B (n = 25) with 41.6 ± 4.9 mg/kg/24 h, and group C with 54.5 ± 5.8 mg/kg/24 h. Their "trough" VPA serum levels were 40.9 ± 13.2, 86.25 ± 11.5, and 137 ± 14.5 ,g/ml, respectively. Fifty healthy children were the controls. Patients and controls underwent clinical and laboratory evaluations including liver function data, complete blood counts, NH3, and so on, after 45 days of VPA treatment. Biotinidase serum levels were evaluated fluorometrically. Results: Liver function data were found elevated in the groups B and C. On the contrary, biotinidase activity was significantly statistically lowered (p < 0.001) in groups B and C (1.22 ± 1.11, 0.97 ± 0.07 mmol/min/L respectively), as compared with controls (5.20 ± 0.90 mmol/min/L). Strong inverse correlations were observed between liver enzymes and VPA blood levels with the activity of the enzyme. Additionally, no inhibitory effect on biotinidase activity was found, when the enzyme was incubated in vitro with high (1.2 mM) concentrations of the drug. Skin lesions (seborrheic rash, alopecia) were improved in our patients after biotin (10 mg/day) supplementation. Conclusions: It is suggested that VPA impairs the liver mitochondrial function, resulting in a low biotinidase activity and or biotin deficiency. Biotin supplementation could restore some of the side effects of the drug. [source] Novel targets for valproic acid: up-regulation of melatonin receptors and neurotrophic factors in C6 glioma cellsJOURNAL OF NEUROCHEMISTRY, Issue 5 2005Lyda M. Rincón Castro Abstract Valproic acid (VPA) is a potent anti-epileptic and effective mood stabilizer. It is known that VPA enhances central GABAergic activity and activates the mitogen-activated protein kinase,extracellular signal-regulated kinase (MAPK,ERK) pathway. It can also inhibit various isoforms of the enzyme, histone deacetylase (HDAC), which is associated with modulation of gene transcription. Recent in vivo studies indicate a neuroprotective role for VPA, which has been found to up-regulate the expression of brain-derived neurotrophic factor (BDNF) in the rat brain. Given the interaction between the pineal hormone, melatonin, and GABAergic systems in the central nervous system, the effects of VPA on the expression of the mammalian melatonin receptor subtypes, MT1 and MT2, were examined in rat C6 glioma cells. The effects of VPA on the expression of glial cell line-derived neurotrophic factor (GDNF) and BDNF were also examined. RT-PCR studies revealed a significant induction of melatonin MT1 receptor mRNA in C6 cells following treatment with 3 or 5 mm VPA for 24 h or 5 mm VPA for 48 h. Western analysis and immunocytochemical detection confirmed that the VPA-induced increase in MT1 mRNA results in up-regulation of MT1 protein expression. Blockade of the MAPK,ERK pathway by PD98059 enhanced the effect of VPA on MT1 expression, suggesting a negative role for this pathway in MT1 receptor regulation. In addition, significant increases in BDNF, GDNF and HDAC mRNA expression were observed after treatment with VPA for 24 or 48 h. Taken together, the present findings suggest that the neuroprotective properties of VPA involve modulation of neurotrophic factors and receptors for melatonin, which is also thought to play a role in neuroprotection. Moreover, the foregoing suggests that combinations of VPA and melatonin could provide novel therapeutic strategies in neurological and psychiatric disorders. [source] Anti-tumor mechanisms of valproate: A novel role for an old drugMEDICINAL RESEARCH REVIEWS, Issue 5 2002Roman A. Blaheta Abstract Valproic acid (VPA, 2-propylpentanoic acid) is an established drug in the long-term therapy of epilepsy. During the past years, it has become evident that VPA is also associated with anti-cancer activity. VPA not only suppresses tumor growth and metastasis, but also induces tumor differentiation in vitro and in vivo. Several modes of action might be relevant for the biological activity of VPA: (1) VPA increases the DNA binding of activating protein-1 (AP-1) transcription factor, and the expression of genes regulated by the extracellular-regulated kinase (ERK)-AP-1 pathway; (2) VPA downregulates protein kinase C (PKC) activity; (3) VPA inhibits glycogen synthase kinase-3, (GSK-3,), a negative regulator of the Wnt signaling pathway; (4) VPA activates the peroxisome proliferator-activated receptors PPAR, and ,; (5) VPA blocks HDAC (histone deacetylase), causing hyperacetylation. The findings elucidate an important role of VPA for cancer therapy. VPA might also be useful as low toxicity agent given over long time periods for chemoprevention and/or for control of residual minimal disease. © 2002 Wiley Periodicals, Inc. Med Res Rev, 22, No. 5, 492,511, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/med.10017 [source] Neuroendocrine transdifferentiation induced by VPA is mediated by PPAR, activation and confers resistance to antiblastic therapy in prostate carcinomaTHE PROSTATE, Issue 6 2008Adriano Angelucci Abstract BACKGROUND Prostate cancer (PCa) is the most commonly diagnosed cancer in men in the Western Countries. When prostatectomy fails to eradicate the primary tumor, PCa is generally refractory to all therapeutic approaches. Valproic acid (VPA) is a promising anticancer agent recently assigned to the class of histone deacetylase (HDAC) inhibitors. However molecular mechanisms underlying VPA action in PCa cells are largely unknown and further experimental validation to prove its potential application in clinic practice is needed. RESULTS In our study we show that VPA is a potent inducer of neuro-endocrine transdifferentiation (NET) in androgen receptor null PCa cells, both in vitro and in vivo. NET was an early event detectable through the expression of neuro-endocrine (NE) markers within 72 hr after VPA treatment and it was associated to a reduction in the overall cell proliferation. When we interrupted VPA treatment we observed the recovery in residual cells of the basal proliferation rate both in vitro and in a xenograft model. The NET process was related to Bcl-2 over-expression in non-NE PCa cells and to the activation of PPAR, in NE cells. The use of specific PPAR, antagonist was able to reduce significantly the expression of NE markers induced by VPA. CONCLUSIONS Our data indicate that the use of VPA as monotherapy in PCa has to be considered with extreme caution, since it may induce an unfavorable NET. In order to counteract the VPA-induced NET, the inhibition of PPAR, may represent a suitable adjuvant treatment strategy and awaits further experimental validation. Prostate 68: 588,598, 2008. © 2008 Wiley-Liss, Inc. [source] Valproic acid increases SMN levels in spinal muscular atrophy patient cells,ANNALS OF NEUROLOGY, Issue 5 2003Charlotte J. Sumner MD Spinal muscular atrophy (SMA) is an inherited motor neuron disease caused by mutation of the telomeric copy of the survival motor neuron gene (SMN1). Although a centromeric copy of the survival motor neuron gene (SMN2) is retained in all patients with SMA, it differs from SMN1 at a critical nucleotide such that the majority of SMN2 transcripts lack exon 7 and encode an unstable, truncated protein. Here, we show that valproic acid increases levels of exon 7,containing SMN transcript and SMN protein in type I SMA patient,derived fibroblast cell lines. Valproic acid may increase SMN levels both by activating the SMN promoter and by preventing exon 7 skipping in SMN transcripts. Valproic acid and related compounds warrant further investigation as potential treatment for SMA. Ann Neurol 2003;54:647,654 [source] Nonstationary disposition of valproic acid during prolonged intravenous infusion: contributions of unbound clearance and protein bindingBIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 6 2001Tori L. Arens Abstract Circadian variations in disposition have been observed for a variety of agents, including anticonvulsants. Valproic acid (VPA), an anticonvulsant used to control generalized and partial seizures, has exhibited diurnal oscillations in steady-state concentrations during long-term administration to humans and non-human primates. The present study was conducted to assess potential diurnal changes in the disposition of VPA during prolonged i.v. infusion in rats. Animals, maintained on a strict 12-h per day light cycle, were equipped with venous cannulae and an arterial microdialysis probe. VPA was administered as a 50-mg/kg loading dose followed by a 42 mg/kg/h infusion for 70 h. Blood and microdialysate samples were obtained at timed intervals after establishment of steady-state throughout two complete light/dark cycles; and total (serum) and unbound (microdialysate) VPA was determined by gas chromatography. Modest oscillations (6,7 h period) in total and unbound VPA were observed; clearance and binding parameters were not different between light and dark periods. However, unbound clearance increased, and unbound fraction decreased, with time over the course of the infusion. These results suggest that time-dependent changes in VPA disposition occur in rats, although oscillations in steady-state concentrations do not appear to be diurnal in nature. Copyright © 2001 John Wiley & Sons, Ltd. [source] Valproic acid and phenobarbital blood levels during the first month of treatment with the ketogenic dietACTA NEUROLOGICA SCANDINAVICA, Issue 4 2010G. Coppola Coppola G, Verrotti A, D'Aniello A, Arcieri S, Operto FF, Della Corte R, Ammendola E, Pascotto A. Valproic acid and phenobarbital blood levels during the first month of treatment with the ketogenic diet. Acta Neurol Scand: 2010: 122: 303,307. © 2010 John Wiley & Sons A/S. Objective,,, The aim of this study was to assess how the ketogenic diet influences the blood levels of antiepileptic drugs in the first month of treatment in a pediatric population with drug-resistant epilepsy. Methods,,, The plasma concentrations of antiepileptic drugs were investigated in an open study on 36 consecutive children and adolescents (20 males), aged between 6 months and 16 years (mean age 4.7 years), who were put on the ketogenic diet because of medically refractory epilepsy. The plasma levels of antiepileptic drugs were determined 30 days and immediately before the diet and on days 8, 15, 22 and 29 after the start of the diet. The daily dose of each drug was not changed during the first month of treatment, while the daily dose of benzodiazepines was reduced by up to 30% if excessive sedation or drowsiness occurred. Results,,, While plasma concentrations of phenobarbital did not change in the first month on the ketogenic diet (mean increase of 2.3 mg/l ± 1.0), valproic acid showed a slight but not significant decrease (mean decresase of 6.7 mg/l ± 3.2), 2 weeks after the start of the diet. Conclusions,,, Adjustments in the daily dose of either drug before the start of the diet do not however appear to be justified. [source] Effects of the antiepileptic drugs on peripheral nerve functionACTA NEUROLOGICA SCANDINAVICA, Issue 1 2010E. Boylu Objective,,, We aimed to compare the effects of antiepileptic drugs and provide findings of peripheral nerve impairment using standard electrophysiological techniques. Materials and methods,,, Young adult outpatients with epilepsy on monotherapy for no less than 6 months with carbamazepine (CBZ), valproic acid (VPA), oxcarbazepine (OXC) and topiramate (TPM) were examined. Patients who had any other disease that could effect nerve conduction studies and who had neuropathic symptoms were excluded. Results,,, Each group contained 15 patients and 20 healthy subjects were examined as the control group. Prolonged latency of median sensory nerve (P = 0.004), ulnar sensory nerve (P = 0.01) and sural nerve (P = 0.003) with a diminished nerve conduction velocity was observed in the CBZ group (P = 0.014, P = 0.002, P = 0.025, respectively). No correlation was found between VPA, OXC and TPM and the nerve conduction studies (P > 0.05). Conclusions,,, Valproic acid, oxcarbazepine and topiramate don't have effects on nerve conduction studies. Mild electrophysiological changes contribute to carbamazepine therapy. [source] Valproic acid blood genomic expression patterns in children with epilepsy , a pilot studyACTA NEUROLOGICA SCANDINAVICA, Issue 3 2004Y. Tang Objective , Valproic acid (VPA) is a commonly used anticonvulsant with multiple systemic effects. The purpose of this pilot study is to examine the blood genomic expression pattern associated with VPA therapy in general and secondly VPA efficacy in children with epilepsy. Materials and methods , Using oligonucleotide microarrays, gene expression in whole blood was assessed in pediatric epilepsy patients following treatment with VPA compared with children with epilepsy prior to initiation of anticonvulsant therapy (drug free patients). Results , The expression of 461 genes was altered in VPA patients (n = 11) compared with drug free patients (n = 7), among which a significant number of serine threonine kinases were down-regulated. Expression patterns in children seizure free on VPA therapy (n = 8) demonstrated 434 up-regulated genes, many in mitochondria, compared with VPA children with continuing seizures (n = 3) and drug free seizure patients (n = 7). Conclusion , VPA therapy is associated with two significant and unique blood gene expression patterns: chronic VPA monotherapy in general and a separate blood genomic profile correlated with seizure freedom. These expression patterns provide new insight into previously undetected mechanisms of VPA anticonvulsant activity. [source] Review of animal models for autism: implication of thyroid hormoneCONGENITAL ANOMALIES, Issue 1 2006Miyuki Sadamatsu ABSTRACT,, Autism is a behaviorally defined disorder associated with characteristic impairments in social interactions and communication, as well as restricted and repetitive behaviors and interest. Its prevalence was once thought to be 2/10 000, but recently several large autism prevalence reviews revealed that the rate of occurrence was roughly 30/10 000. While it has been considered a developmental disorder, little is certain about its etiology. Neuroanatomical studies at the histological level in the brains of autistic patients provide many arguments in the etiology of autism. Results from postmortem and imaging studies have implicated many major structures of the brain including the limbic system, cerebellum, corpus callosum, basal ganglia and brainstem. There is no single biological or clinical marker for autism. While several promising candidate genes have been presented, the critical loci are yet unknown. Environmental influences such as rubella virus, valproic acid, and thalidomide exposure during pregnancy are also considered important, as concordance in monozygotic twins is less than 100% and the phenotypic expression of the disorder varies widely. It is thus hypothesized that non-genetic mechanisms contribute to the onset of autistic syndrome. In light of these ambiguities, hope is held that an animal model of autism may help elucidate matters. In this article, we overview most of the currently available animal models for autism, and propose the rat with mild and transient neonatal hypothyroidism as a novel model for autism. [source] Preclinical abuse potential assessment of the anticonvulsant zonisamideDRUG DEVELOPMENT RESEARCH, Issue 2 2001Jenny L. Wiley Abstract Zonisamide (Zonegran®) is a broad-spectrum antiepileptic agent that shares some pharmacological properties with other anticonvulsants, including phenytoin, carbamazepine, and valproic acid, but is differentiated from these agents by the ability to significantly block T-type calcium channels. Zonisamide interacts with the ,-amino-butyric acid (GABA) receptor in an allosteric manner, and thus does not modulate GABA receptor effects. However, given the potential of drugs within the latter class for drug abuse in humans, an evaluation of zonisamide for abuse potential is an important component of its potential side-effect profile. In the present study, zonisamide was tested in animal models of the subjective and reinforcing effects of central nervous system (CNS) depressant drugs, e.g., diazepam discrimination in rats and intravenous self-administration in rhesus monkeys, respectively. In addition, zonisamide was evaluated for physical dependence liability in a chronic infusion model using rats. Zonisamide did not substitute for diazepam in rats trained to discriminate 2.5-mg/kg diazepam from vehicle nor was it self-administered by rhesus monkeys experienced in methohexital-reinforced responding. Continuous infusion of zonisamide (400 or 600 mg/kg/day) did not prevent the loss of body weight associated with discontinued pentobarbital infusion. These doses of zonisamide did produce some incomplete attenuation of observable signs of pentobarbital withdrawal, likely due to direct sedative or depressant effects of these high doses. These results suggest that zonisamide would not produce diazepam-like intoxication in humans nor would it likely be subject to abuse when made more widely available. Further, when administered chronically, zonisamide would not be expected to produce physical dependence of the CNS depressant type. Taken together, these results support the prediction that zonisamide would have low abuse liability. Drug Dev. Res. 54:66,74, 2001. © 2001 Wiley-Liss, Inc. [source] Quantitation of valproic acid in pharmaceutical preparations using dispersive liquid-liquid microextraction followed by gas chromatography-flame ionization detection without prior derivatizationDRUG TESTING AND ANALYSIS, Issue 7 2010Hamid Reza Sobhi Abstract Dispersive liquid-liquid microextraction (DLLME), coupled with gas chromatography-flame ionization detection (GC-FID), has been successfully used for the extraction and determination of valproic acid (VPA) in pharmaceutical preparations. In the developed method, an appropriate mixture of extracting and disperser solvents was rapidly injected into an aqueous sample. Having formed a cloudy solution, the mixture was centrifuged and then the extracting solvent was sedimented at the bottom of a conical test tube. The extract was then injected into a GC system directly, without any further pretreatment. Initially, microextraction efficiency factors were optimized and the optimum experimental conditions found were as follows: tetrachloroethylene (9.0 µL) as extracting solvent; acetone (1.0 mL) as disperser solvent; 5 mL acidic aqueous sample (pH 1) without salt addition. Under the selected conditions, the calibration curve showed linearity in the range of 0.1,5.0 mg/L with regression coefficient corresponding to 0.9998. The limit of detection was found to be 0.05 mg/L. Finally, the method was applied for the determination of VPA in two different pharmaceutical preparations. A reasonable intra-assay (3.9,10.8%, n = 3) and inter-assay (5.6,11.4%, n = 3) precision illustrated the good performance of the analytical procedure. The protocol proved to be rapid and cost-effective for screening purposes. Copyright © 2010 John Wiley & Sons, Ltd. [source] The metabolic syndrome in overweight epileptic patients treated with valproic acidEPILEPSIA, Issue 2 2010Alberto Verrotti Summary Purpose:, To evaluate the presence of metabolic syndrome (MS) in children and adolescents treated with valproate (VPA). Methods:, One hundred fourteen patients (54 male and 60 female) were studied. These patients were followed from the beginning of therapy for at least 24 months; at the end of follow-up, 46 patients (40.4%) had a considerable increase in body weight, whereas the other patients (59.6%) remained with the same weight. The MS was defined as having at least three of the following: abdominal obesity, dyslipidemia, glucose intolerance, and hypertension. Results:, Forty-six patients developed obesity; 20 (43.5%) of 46 patients developed MS. Abnormal glucose homeostasis was identified in 45% of patients. High total serum cholesterol concentrations were noted in 10 (50%), high serum triglyceride concentrations in 7 (35%), and low high-density lipoprotein (HDL) in 15 (75%) of the 20 subjects with MS. However, there were no significant differences in the features of MS between boys and girls with MS. Conclusions:, Patients who gain weight during VPA therapy can develop MS with a possible risk of cardiovascular disease. [source] Ghrelin levels are reduced in prepubertal epileptic children under treatment with carbamazepine or valproic acidEPILEPSIA, Issue 2 2010Flavia Prodam Summary A relationship between ghrelin and epilepsy has been already shown in humans, although the results are controversial. Ghrelin levels are reduced in obesity. Epileptic patients progressively develop a therapy-linked weight gain; however, the mechanisms for this have not been fully explained. The aim of our study is to evaluate if ghrelin secretion is modulated by treatment with carbamazepine or valproic acid in young prepubertal epileptic children. Ghrelin levels were reduced in normal-weight young epileptic prepubertal children under treatment with carbamazepine (p < 0.0001) or valproic acid (p < 0.006) compared to healthy age- and weight-matched subjects. Ghrelin was also lower in children under carbamazepine when compared to those under valproic acid (p < 0.01). A derangement in ghrelin secretion in epilepsy during specific pharmacologic therapies and independent of weight gain could be hypothesized. [source] Histologic and morphologic effects of valproic acid and oxcarbazepine on rat uterine and ovarian cellsEPILEPSIA, Issue 1 2010Ali Cansu Summary Purpose:, To determine the histologic and morphologic effects of valproic acid (VPA) and oxcarbazepine (OXC) on rat uterine and ovarian cells. Methods:, Fifty-six female prepubertal Wistar rats (21,24 days old and weighing between 47.5 and 58.1 g) were divided equally into four groups, which were given drinking water (controls), 300 mg/kg/day of VPA, 100 mg/kg/day of OXC or VPA + OXC via gavage, for 90 days. Ovaries and uteri of rats on proestrous and diestrous phases of estrous cycle were extirpated and placed in a fixation solution. The tissue specimens were assessed with apoptosis (TUNEL) staining protocols, eosinophil counting, and electron microscopic techniques. Results:, In uteri, apoptosis in stroma, mitochondrial swelling, and cristolysis were observed in the VPA group, and OXC led to negative effects on epithelial cell and intracellular edema. In ovaries, both drugs increased apoptosis and intracytoplasmic edema. Organelle structure disruption was also observed in the OXC group. More conspicuous degenerative modifications were determined in the VPA + OXC group. In uteri, the number of TUNEL-positive luminal epithelial cells was 7.20 ± 1.32 in controls, and significantly increased to 29.60 ± 1.58, 34.20 ± 2.53, and 54.80 ± 2.04 in VPA, OXC, and VPA + OXC groups, respectively (p < 0.001). The highest number of TUNEL-positive glandular epithelium cells was observed in the VPA + OXC group; however, the number of TUNEL-positive stroma cells was highest in the VPA group. The highest number of eosinophils in stroma was in the VPA group. Conclusion:, VPA and OXC trigger apoptotic and degenerative effects on rat uterine and ovarian cells. VPA also prevents implantation of embryo to the uterus and causes abortion via endometrial eosinophil infiltration. [source] Rufinamide: Clinical pharmacokinetics and concentration,response relationships in patients with epilepsyEPILEPSIA, Issue 7 2008Emilio Perucca Summary Rufinamide is a new, orally active antiepileptic drug (AED), which has been found to be effective in the treatment of partial seizures and drop attacks associated with the Lennox-Gastaut syndrome. When taken with food, rufinamide is relatively well absorbed in the lower dose range, with approximately dose-proportional plasma concentrations up to 1,600 mg/day, but less than dose-proportional plasma concentrations at higher doses due to reduced oral bioavailability. Rufinamide is not extensively bound to plasma proteins. During repeated dosing, steady state is reached within 2 days, consistent with its elimination half-life of 6,10 h. The apparent volume of distribution (Vd/F) and apparent oral clearance (CL/F) are related to body size, the best predictor being body surface area. Rufinamide is not a substrate of cytochrome P450 (CYP450) enzymes and is extensively metabolized via hydrolysis by carboxylesterases to a pharmacologically inactive carboxylic acid derivative, which is excreted in the urine. Rufinamide pharmacokinetics are not affected by impaired renal function. Potential differences in rufinamide pharmacokinetics between children and adults have not been investigated systematically in formal studies. Although population pharmacokinetic modeling suggests that in the absence of interacting comedication rufinamide CL/F may be higher in children than in adults, a meaningful comparison of data across age groups is complicated by age-related differences in doses and in proportion of patients receiving drugs known to increase or to decrease rufinamide CL/F. A study investigating the effect of rufinamide on the pharmacokinetics of the CYP3A4 substrate triazolam and an oral contraceptive interaction study showed that rufinamide has some enzyme-inducing potential in man. Findings from population pharmacokinetic modeling indicate that rufinamide does not modify the CL/F of topiramate or valproic acid, but may slightly increase the CL/F of carbamazepine and lamotrigine and slightly decrease the CL/F of phenobarbital and phenytoin (all predicted changes were <20%). These changes in the pharmacokinetics of associated AEDs are unlikely to make it necessary to change the dosages of these AEDs given concomitantly with rufinamide, with the exception that consideration should be given to reducing the dose of phenytoin. Based on population pharmacokinetic modeling, lamotrigine, topiramate, or benzodiazepines do not affect the pharmacokinetics of rufinamide, but valproic acid may increase plasma rufinamide concentrations, especially in children in whom plasma rufinamide concentrations could be increased substantially. Conversely, comedication with carbamazepine, vigabatrin, phenytoin, phenobarbital, and primidone was associated with a slight-to-moderate decrease in plasma rufinamide concentrations, ranging from a minimum of ,13.7% in female children comedicated with vigabatrin to a maximum of ,46.3% in female adults comedicated with phenytoin, phenobarbital, or primidone. In population modeling using data from placebo-controlled trials, a positive correlation has been identified between reduction in seizure frequency and steady-state plasma rufinamide concentrations. The probability of adverse effects also appears to be concentration-related. [source] Anticonvulsant profile and teratogenicity of 3,3-dimethylbutanoylurea: A potential for a second generation drug to valproic acidEPILEPSIA, Issue 7 2008Jakob Avi Shimshoni Summary Purpose: The purpose of this study was to evaluate the anticonvulsant activity and teratogenic potential of branched aliphatic acylureas represented by isovaleroylurea (IVU), pivaloylurea (PVU) and 3,3-dimethylbutanoylurea (DBU), as potential second-generation drugs to valproic acid (VPA). Methods: The anticonvulsant activity of IVU, PVU, and DBU was determined in mice and rats utilizing the maximal electroshock seizure (MES) and the pentylenetetrazole (scMet) tests. The ability of DBU to block electrical-, or chemical-induced seizures was further examined in three acute seizure models: the psychomotor 6 Hz model, the bicuculline and picrotoxin models and one model of chronic epilepsy (i.e., the hippocampal kindled rat model). The induction of neural tube defects (NTDs) by IVU, PVU, and DBU was evaluated after i.p. administration at day 8.5 of gestation to a mouse strain highly susceptible to VPA-induced teratogenicity. The pharmacokinetics of DBU was studied following i.v. administration to rats. Results: DBU emerged as the most potent compound having an MES-ED50of 186 mg/kg (mice) and 64 mg/kg (rats) and an scMet-ED50of 66 mg/kg (mice) and 26 mg/kg (rats). DBU underwent further evaluation in the hippocampal kindled rat (ED50= 35 mg/kg), the psychomotor 6 Hz mouse model (ED50= 80 mg/kg at 32 mA and ED50= 133 mg/kg at 44 mA), the bicuculline- and picrotoxin-induced seizure mouse model (ED50= 205 mg/kg and 167 mg/kg, respectively). In contrast to VPA, DBU, IVU, and PVU did not induce a significant increase in NTDs as compared to control. DBU was eliminated by metabolism with a half-life of 4.5 h. Conclusions: DBU's broad spectrum and potent anticonvulsant activity, along with its high safety margin and favorable pharmacokinetic profile, make it an attractive candidate to become a new, potent, and safe AED. [source] Adiponectin and visfatin concentrations in children treated with valproic acidEPILEPSIA, Issue 2 2008Markus Rauchenzauner Summary Chronic antiepileptic therapy with valproic acid (VPA) is associated with increased body weight and insulin resistance in adults and children. Attempts to determine the underlying pathophysiologic mechanisms have failed. Adipocytokines have recently been defined as a link between glucose and fat metabolism. We herein demonstrate that VPA-associated overweight is accompanied by lower adiponectin and higher leptin concentrations in children. The absence of any relationship with visfatin concentration does not suggest a role of this novel insulin-mimetic hormone in VPA-associated metabolic alterations. Therefore, adiponectin and leptin but not visfatin may be considered as potential regulators of glucose and fat metabolism during VPA-therapy. [source] Interaction between Anticonvulsants and Human Placental Carnitine TransporterEPILEPSIA, Issue 3 2004Shu-Pei Wu Summary: Purpose: To examine the inhibitory effect of anticonvulsants (AEDs) on carnitine transport by the human placental carnitine transporter. Methods: Uptake of radiolabeled carnitine by human placental brush-border membrane vesicles was measured in the absence and presence of tiagabine (TGB), vigabatrin (VGB), gabapentin (GBP), lamotrigine (LTG), topiramate (TPM), valproic acid (VPA), and phenytoin (PHT). The mechanism of the inhibitory action of TGB was determined. Results: Most of the AEDs inhibited placental carnitine transport. Kinetic analyses showed that TGB had the greatest inhibitory effect [50% inhibitory concentration (IC50, 190 ,M)], and the order of inhibitory potency was TGB > PHT > GBP > VPA > VGB, TPM > LTG. Further studies showed that TGB competitively inhibited carnitine uptake by the human placental carnitine transporter, suggesting that it may be a substrate for this carrier. Conclusions: Although the involvement of carnitine deficiency in fetal anticonvulsant syndrome requires further evaluation, potential interference with placental carnitine transport by several AEDs was demonstrated. Despite the higher inhibitory potency of TGB, given the therapeutic unbound concentrations, the results for VPA and PHT are probably more clinically significant. [source] Anticonvulsant Profile and Teratogenicity of N -methyl-tetramethylcyclopropyl Carboxamide: A New Antiepileptic DrugEPILEPSIA, Issue 2 2002Nina Isoherranen Summary: ,Purpose: The studies presented here represent our efforts to investigate the anticonvulsant activity of N -methyl-tetramethylcyclopropyl carboxamide (M-TMCD) and its metabolite tetramethylcyclopropyl carboxamide (TMCD) in various animal (rodent) models of human epilepsy, and to evaluate their ability to induce neural tube defects (NTDs) and neurotoxicity. Methods: The anticonvulsant activity of M-TMCD and TMCD was determined after intraperitoneal (i.p.) administration to CF#1 mice, and either oral or i.p. administration to Sprague,Dawley rats. The ability of M-TMCD and TMCD to block electrical-, chemical-, or sensory-induced seizures was examined in eight animal models of epilepsy. The plasma and brain concentrations of M-TMCD and TMCD were determined in the CF#1 mice after i.p. administration. The induction of NTDs by M-TMCD and TMCD was evaluated after a single i.p. administration at day 8.5 of gestation in a highly inbred mouse strain (SWV) that is susceptible to valproic acid,induced neural tube defects. Results: In mice, M-TMCD afforded protection against maximal electroshock (MES)-induced, pentylenetetrazol (Metrazol)-induced, and bicuculline-induced seizures, as well as against 6-Hz "psychomotor" seizures and sound-induced seizures with ED50 values of 99, 39, 81, 51, and 10 mg/kg, respectively. In rats, M-TMCD effectively prevented MES- and Metrazol-induced seizures and secondarily generalized seizures in hippocampal kindled rats (ED50 values of 82, 45, and 39 mg/kg, respectively). Unlike M-TMCD, TMCD was active only against Metrazol-induced seizures in mice and rats (ED50 values of 57 and 52 mg/kg, respectively). Neither M-TMCD nor TMCD was found to induce NTDs in SWV mice. Conclusions: The results obtained in this study show that M-TMCD is a broad-spectrum anticonvulsant drug that does not induce NTDs and support additional studies to evaluate its full therapeutic potential. [source] Absence Seizures Aggravated by Valproic AcidEPILEPSIA, Issue 7 2001Tally Lerman-Sagie Summary: ,Purpose: To report on pediatric patients with absence epilepsy who experienced absence seizure aggravation while receiving valproic acid (VPA). Methods: The charts of all children from four pediatric epilepsy clinics receiving VPA for absence epilepsy were reviewed. Patients were evaluated and followed up between 1994 and 2000. Results: Eight cases (six boys) of absence seizure aggravation were detected. Mean age at seizure onset was 5.8 years (range, 3,12 years). Six patients had simple absence seizures, one had myoclonic absences, and one had absences with automatisms. The electroencephalogram in all cases depicted generalized 3-Hz spike-and-wave activities. All eight patients experienced an increase in the frequency of absence seizures within days of VPA introduction. Dose increments resulted in further seizure aggravation. Serum levels of VPA were within therapeutic range in all patients. No case was attributed to VPA-induced encephalopathy. All patients improved on VPA discontinuation. In five children, VPA was reintroduced, resulting in further seizure aggravation. Conclusions: VPA can occasionally provoke absence seizure aggravation in patients with absence epilepsy. [source] Teratogenic Effects of Antiepileptic Drugs: Use of an International Database on Malformations and Drug Exposure (MADRE)EPILEPSIA, Issue 11 2000Carla Arpino Summary: Purpose: The study goal was to assess teratogenic effects of antiepileptic drugs (AEDs) through the use of a surveillance system (MADRE) of infants with malformations. Methods: Information on all malformed infants (1990,1996) with maternal first-trimester drug exposure was collected by the International Clearinghouse for Birth Defects and Monitoring Systems (ICBDMS). Cases were defined as infants presenting with a specific malformation, and controls were defined as infants presenting with any other birth defect. Exposure was defined by the use of AEDs during the first trimester of pregnancy. The association of AEDs with malformations was then estimated by calculating the odds ratios with 95% confidence intervals and testing their homogeneity among registries. Results: Among 8005 cases of malformations, 299 infants were exposed in utero to AEDs. Of those exposed to monotherapy, 65 were exposed to phenobarbital, 10 to methylphenobarbital, 80 to valproic acid, 46 to carbamazepine, 24 to phenytoin, and 16 to other AEDs. Associations were found for spina bifida with valproic acid. Infants exposed to phenobarbital and to methylphenobarbital showed an increased risk of oral clefts. Cardiac malformations were found to be associated with phenobarbital, methylphenobarbital, valproic acid, and carbamazepine. Hypospadias was associated with valproic acid. Porencephaly and other specified anomalies of brain, anomalies of face, coarctation of aorta, and limb reduction defects were found to be associated with valproic acid. Conclusions: Using the MADRE system, we confirmed known teratogenic effects of AEDs. We also found increased risks for malformations that had never been reported associated with AEDs or for which the association was suggested by case reports. [source] Developmental and Therapeutic Pharmacology of Antiepileptic DrugsEPILEPSIA, Issue 2000Hisao Miura Summary: We investigated the clinical effects and plasma levels of zonisamide (ZNS) in children with cryptogenic localization-related epilepsies. ZNS is absorbed slowly from the gastrointestinal tract, and its biological half-life is long as compared with that of other common antiepileptic drugs. The peak-to-trough plasma level ratios during a day were as small as 1.28 ± 0.15 in children taking a daily dose of 8 mg/kg of ZNS once a day as a single drug. The plasma level (,g/ml) to dose (mg/kg/day) ratios estimated by the trough and peak plasma levels both increased with advancing age, but the peak-to-trough plasma level ratios were maintained almost uniformly throughout the pediatric age period. A wide range of the plasma levels was associated with complete freedom from seizures. The range of the plasma levels in patients who did not respond to ZNS was higher than that in the controlled group. However, the clinical effects of ZNS were in agreement with the range of generally accepted therapeutic plasma levels of ZNS, 15,40 ,g/ml. Any patient who receives polytherapy is at risk to develop 1 or more drug interactions. Concurrent administration of carbamazepine (CBZ) decreases plasma concentrations of ZNS. However, ZNS does not alter plasma concentrations of CBZ or its primary metabolite, carbamazepine-10,11-epoxide (CBZ-E). It is evident that the concurrent administration of lamotrigine (LTG) affects plasma concentrations of CBZ-E, while plasma CBZ levels remain unaltered. However, the effect of LTG on plasma concentrations of CBZ-E is small, and none of the study patients showed toxic plasma concentrations of CBZ-E or associated clinical toxicity. Drug-protein binding interactions are another source of side effects. A simultaneous administration of valproic acid increases the total plasma CBZ-E levels relative to the CBZ dose associated with the raised free fractions of CBZ and CBZ-E. The high free plasma concentrations of CBZ-E above 1.5 ,g/ml may be responsible for the side effects. [source] Valproic Acid-Induced Hyperammonemic Encephalopathy with Triphasic WavesEPILEPSIA, Issue 7 2000Akira Kifune Summary: Purpose: To examine a patient with valproic acid (VPA)-induced hyperammonemic encephalopathy accompanied by triphasic waves. Methods: A 61-year-old male patient with epilepsy experienced disturbance of consciousness after VPA dose was increased because of poor seizure control. The electroencephalogram (EEG) taken on admission revealed triphasic waves and high-amplitude ,-activity with frontal predominance. Although serum hepatic enzymes, such as AST and ALT, were normal, serum ammonium level was high at 96 ,g/dl (normal range, 3,47 ,g/dl). Serum amino acid analysis showed multiple minor abnormalities. Administration of VPA was discontinued immediately after admission, while other anticonvulsants were continued. Results: The patient's condition was improved on the fourth day of admission. An EEG, serum ammonium level, and amino acid profile were normal on the eighth day. Based on VPA administration, serum ammonium levels, and results of amino acid analysis, this patient had VPA-induced hyperammonemic encephalopathy. Conclusions: Our case indicates that caution is required if triphasic waves appear in VPA-induced hyperammonemic encephalopathy. [source] | |||||||||||||||||||||||||||||||||||||