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Antiepileptic Drugs (antiepileptic + drug)
Kinds of Antiepileptic Drugs Terms modified by Antiepileptic Drugs Selected AbstractsAnticonvulsant 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] Prognostic Significance of Failure of the Initial Antiepileptic Drug in Children with Absence EpilepsyEPILEPSIA, Issue 6 2001Elaine Wirrell Summary: ,Purpose: In children with childhood absence epilepsy (CAE) and juvenile absence epilepsy (JAE), to determine the impact of failure of initial antiepileptic drug (AED) for lack of efficacy in eventual seizure control and long-term remission of epilepsy. Methods: Centralized EEG records for the province of Nova Scotia allowed identification of all children seen with CAE or JAE between 1977 and 1985. Information regarding success or failure of initial AED in fully controlling seizures and long-term seizure control and remission of epilepsy was collected by patient questionnaire and chart review. Results: Eighty-six of 92 eligible patients were followed up (75 CAE, 11 JAE). Initial AED treatment was successful in 52 (60%) of 86. Success tended to be greater for valproate (VPA) than for other AEDs (p = 0.07), and lower if generalized tonic,clonic or myoclonic seizures coexisted (p < 0.004 and p < 0.03). Terminal remission was more likely if the initial AED was successful than if it had failed (69% vs. 41%; p < 0.02). Compared with those in whom the initial AED was successful, subjects whose initial AED had failed were more likely to progress to juvenile myoclonic epilepsy (JME) at last follow-up (32% vs. 10%; p < 0.02) and to develop intractable epilepsy (17% vs. 2%; p < 0.04). Conclusions: Initial AED was successful in 60% of children with AE. If the first AED failed, the outcome was less favorable, with a lower rate of terminal remission and a higher rate of progression to JME and intractable epilepsy. [source] The teratogenic risk of antiepileptic drug polytherapyEPILEPSIA, Issue 5 2010Frank J. E. Vajda Summary Purpose:, To compare the risks of fetal malformation during pregnancy associated with antiepileptic drug (AED) polytherapy and monotherapy. Methods:, Statistical analysis of malformation rate and antiepileptic drug exposure data from the Australian Register of Antiepileptic Drugs in Pregnancy, and from the literature. Results:, The calculated relative risk (RR) value for AED polytherapy compared with monotherapy was below 1.0 in only 3 of 14 literature publications. In the register, at 1 year postnatally there were fetal malformations in 5.32% of 282 AED polytherapy pregnancies, and in 7.84% of 791 AED monotherapy pregnancies, an RR of 0.68 [95% confidence interval (CI) 0.39,1.17). For pregnancies exposed to valproate, the RR of fetal malformation (0.39, 95% CI 0.20,0.89) was lower in polytherapy (7.26%) than in monotherapy (17.9%); the difference did not depend on valproate dosage. The RR values for fetal malformation were not significantly different for AED polytherapy and monotherapy when valproate was not involved. Logistic regression suggested that coadministration of lamotrigine may have reduced the malformation risk from valproate. Discussion:, The fetal hazard of AED polytherapy relative to monotherapy may depend more on the degree of exposure to valproate than on the fact of polytherapy per se. Coadministration with lamotrigine may lower the fetal risk of valproate therapy. [source] Generic Products of Antiepileptic Drugs (AEDs): Is It an Issue?EPILEPSIA, Issue 10 2007Meir Bialer Summary:, The availability of generic products of antiepileptic drugs (AEDs) has raised the following concerns: (1) Do generic AEDs work as well as brand AEDs in terms of their efficacy, safety and quality? (2) Can generic AEDs be used as substitutions for brand AEDs? and (3) Can generic products of AEDs be used interchangeably? The traditional average bioequivalence analysis addresses concern 1 but does not provide a complete adequate response to concerns 2 and 3. Drug interchangeability can be classified as drug prescribability or drug switchability. Drug prescribability refers to the situation where a patient is treated for the first time so that either a brand or a bioequivalent generic AED can be chosen. Drug switchability refers to the situation in which a brand AED is switched to a bioequivalent generic product of the same AED. The traditional average bioequivalence approach is sufficient to evaluate the prescribability of generic products, but does not ensure the switchability between prescribable formulations. The necessity of assuring switchability of two formulations can be addressed by individual bioequivalence. While the switch to generic AEDs is well tolerated by many patients and in general cost-effective, seizure control should not be sacrificed on the basis of cost alone, as the major end point in treating epilepsy with AEDs is seizure control without side effects. Until we have individual (within patient) bioequivalence data on generic AEDs and/or the tools to a priori identify the subset of patients susceptible to the generic switch, a switch of AED products in seizure-free patients is not recommended. [source] The Pharmacokinetics of Antiepileptic Drugs in Rats: Consequences for Maintaining Effective Drug Levels during Prolonged Drug Administration in Rat Models of EpilepsyEPILEPSIA, Issue 7 2007Wolfgang Löscher Summary:, Rodent models of chronic epilepsy with spontaneous recurrent seizures likely represent the closest parallel to the human condition. Such models may be best suited for therapy discovery for pharmacoresistant epilepsy and for antiepileptogenic or disease-modifying therapeutics. However, the use of such rodent models for therapy discovery creates problems with regard to maintaining effective drug levels throughout a prolonged testing period. This is particularly due to the fact that rodents such as rats and mice eliminate most drugs much more rapidly than humans. Thus, knowledge about elimination rate of a test drug in a laboratory species is essential for development of a treatment paradigm that allows maintaining adequate drug levels in the system over the period of treatment. Currently, the most popular models of epilepsy with spontaneous seizures are poststatus epilepticus models of temporal lobe epilepsy in rats. Such models are both used for studies on antiepileptogenesis and drug resistance. For validation of these models, current antiepileptic drugs (AEDs) have to be used. In this article, the elimination rates of these AEDs and their effective plasma levels in rats are reviewed as a guide for developing treatment protocols for chronic drug testing. The advantages and disadvantages of several technologies for drug delivery are discussed, and some examples for calculation of adequate treatment protocols are given. As shown in this review, because of the rapid elimination of most AEDs in rats, it is no trivial task to maintain effective steady-state AED levels in the plasma throughout the day over multiple days to ensure that there will be adequate levels in the system for the purpose of the experiment. However, the use of an adequate dosing regimen that is based on elimination rate is an absolute prerequisite when using rat models for discovery of new antiepileptogenic therapies or therapies for pharmacoresistant epilepsy, because otherwise such models may lead to erroneous conclusions about drug efficacy. [source] Experimental and Clinical Evidence for Loss of Effect (Tolerance) during Prolonged Treatment with Antiepileptic DrugsEPILEPSIA, Issue 8 2006Wolfgang Löscher Summary:, Development of tolerance (i.e., the reduction in response to a drug after repeated administration) is an adaptive response of the body to prolonged exposure to the drug, and tolerance to antiepileptic drugs (AEDs) is no exception. Tolerance develops to some drug effects much more rapidly than to others. The extent of tolerance depends on the drug and individual (genetic?) factors. Tolerance may lead to attenuation of side effects but also to loss of efficacy of AEDs and is reversible after discontinuation of drug treatment. Different experimental approaches are used to study tolerance in laboratory animals. Development of tolerance depends on the experimental model, drug, drug dosage, and duration of treatment, so that a battery of experimental protocols is needed to evaluate fully whether tolerance to effect occurs. Two major types of tolerance are known. Pharmacokinetic (metabolic) tolerance, due to induction of AED-metabolizing enzymes has been shown for most first-generation AEDs, and is easy to overcome by increasing dosage. Pharmacodynamic (functional) tolerance is due to "adaptation" of AED targets (e.g., by loss of receptor sensitivity) and has been shown experimentally for all AEDs that lose activity during prolonged treatment. Functional tolerance may lead to complete loss of AED activity and cross-tolerance to other AEDs. Convincing experimental evidence indicates that almost all first-, second-, and third-generation AEDs lose their antiepileptic activity during prolonged treatment, although to a different extent. Because of diverse confounding factors, detecting tolerance in patients with epilepsy is more difficult but can be done with careful assessment of decline during long-term individual patient response. After excluding confounding factors, tolerance to antiepileptic effect for most modern and old AEDs can be shown in small subgroups of responders by assessing individual or group response. Development of tolerance to the antiepileptic activity of an AED may be an important reason for failure of drug treatment. Knowledge of tolerance to AED effects as a mechanism of drug resistance in previous responders is important for patients, physicians, and scientists. [source] Evidence-based Treatment of Idiopathic Generalized Epilepsies with Older Antiepileptic DrugsEPILEPSIA, Issue 2005Nikolas Hitiris Summary:, Older antiepileptic drugs continue to play a major role in the treatment of the idiopathic generalized epilepsies. Comparative studies of ethosuximide and valproate have demonstrated equivalence in the treatment of childhood absence epilepsy. Valproate can be regarded as the recommended first-line treatment for juvenile myoclonic epilepsy based on case series reports. Studies in patients with generalized tonic-clonic seizures have not separated out idiopathic from secondary generalized events. Treatment for the other idiopathic generalized epilepsy syndromes lacks evidence other than a few case reports and diverse expert opinion. Further randomized controlled trials of older antiepileptic drugs are recommended to solidify the evidence-based treatment of the idiopathic generalized epilepsies. [source] Hyperhomocysteinemia in Children Treated with Antiepileptic Drugs Is Normalized by Folic Acid SupplementationEPILEPSIA, Issue 10 2005Martina Huemer Summary:,Purpose: To assess the prevalence of hyperhomocysteinemia in pediatric patients treated with antiepileptic drugs (AEDs) and to evaluate the effect of folic acid supplementation on plasma total homocysteine (tHcy) concentrations in hyperhomocysteinemic patients. Methods: 123 patients from three regional hospitals participated in the study. Patients with hyperhomocysteinemia were included in a 3-month double-blind randomized trial testing oral folic acid supplementation (1 mg/day) versus placebo. Results: Hyperhomocysteinemia (tHcy >10.4 ,mol/L) was present in 19 of 123 patients. Patients with hyperhomocysteinemia were older (13.7 ± 4 vs. 11.0 ± 3.9 years) and had significantly lower folate and cobalamin concentrations. Multidrug (two or more) AED treatment and duration of therapy correlated significantly with elevated total homocysteine (tHcy) and low folate. In contrast, polymorphisms in the methylene tetrahydrofolate reductase gene (MTHFR 677 C,T, 1298 A,C, 1793 G,A) had no significant impact on tHcy. Nine of 19 patients with hyperhomocysteinemia were randomized to placebo, whereas the remaining 10 patients received folic acid supplementation. Folic acid supplementation resulted in a significant increase of folate and decrease of tHcy, whereas both parameters remained unchanged in the placebo group. Conclusions: Hyperhomocysteinemia is present in 15.5% of children receiving long-term AED treatment. Multidrug treatment and long duration of therapy enhance the risk for hyperhomocysteinemia. Folic acid supplementation significantly reduces tHcy. We recommend assessment of serum folate and plasma tHcy in children receiving AEDs. [source] Response: Efficacy and Tolerability of the New Antiepileptic DrugsEPILEPSIA, Issue 12 2004Jacqueline A. French No abstract is available for this article. [source] Efficacy and Tolerability of the New Antiepileptic Drugs, II: Treatment of Refractory Epilepsy.EPILEPSIA, Issue 11 2004QSS Subcommittees of the American Academy of Neurology, Report of the TTA, the American Epilepsy Society No abstract is available for this article. [source] Australian Pregnancy Registry of Women Taking Antiepileptic DrugsEPILEPSIA, Issue 11 2004Frank Vajda No abstract is available for this article. [source] Efficacy and Tolerability of the New Antiepileptic Drugs, I: Treatment of New-Onset Epilepsy: Report of the TTA and QSS Subcommittees of the American Academy of Neurology and the American Epilepsy SocietyEPILEPSIA, Issue 5 2004Jacqueline A. French Summary: Purpose: To assess the evidence demonstrating efficacy, tolerability, and safety of seven new antiepileptic drugs [AEDs; gabapentin (GBP), lamotrigine (LTG), topiramate (TPM), tiagabine (TGB), oxcarbazepine (OXC), levetiracetam (LEV), and zonisamide (ZNS), reviewed in the order in which these agents received approval by the U.S. Food and Drug Administration] in the treatment of children and adults with newly diagnosed partial and generalized epilepsies. Methods: A 23-member committee, including general neurologists, pediatric neurologists, epileptologists, and doctors in pharmacy, evaluated the available evidence based on a structured literature review including MEDLINE, Current Contents, and Cochrane Library for relevant articles from 1987 until September 2002, with selected manual searches up to 2003. Results: Evidence exists, either from comparative or dose-controlled trials, that GBP, LTG, TPM, and OXC have efficacy as monotherapy in newly diagnosed adolescents and adults with either partial or mixed seizure disorders. Evidence also shows that LTG is effective for newly diagnosed absence seizures in children. Evidence for effectiveness of the new AEDs in newly diagnosed patients with other generalized epilepsy syndromes is lacking. Conclusions: The results of this evidence-based assessment provide guidelines for the prescription of AEDs for patients with newly diagnosed epilepsy and identify those seizure types and syndromes for which more evidence is necessary. [source] Stopping Antiepileptic Drugs after Successful Surgery: What Do We Know? and What Do We Still Need to Learn?EPILEPSIA, Issue 2 2004Anne T. Berg No abstract is available for this article. [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] Interactions Between Oxcarbazepine and Conventional Antiepileptic Drugs in the Maximal Electroshock Test in Mice: An Isobolographic AnalysisEPILEPSIA, Issue 4 2003Jarogniew J. Luszczki Summary: ,Purpose: The aim of this study was to determine the types of interactions between oxcarbazepine (OCBZ) and conventional antiepileptic drugs (AEDs) against maximal electroshock-induced seizures (MES test) in mice, by using a method of isobolographic analysis. Methods: Adverse effects of combinations were evaluated in the chimney test (motor performance), also using the isobolographic method, which allowed determination of the median toxic dose (TD50) values for individual combinations; thus the protective indices could be determined. Results: OCBZ and phenytoin (PHT) at the fixed-ratio combination of 1:1 were significantly infraadditive (antagonistic) with respect to the antiseizure protection against MES and simultaneously additive in terms of side effects in the chimney test. Interestingly, combinations between OCBZ and clonazepam (CZP) in the MES test proved antagonistic or synergistic, depending on the proportion of both AEDs in the mixture. Low doses of OCBZ with high doses of CZP exerted antagonism. Conversely, high doses of OCBZ combined with low doses of CZP resulted in a synergistic interaction. Remaining combinations between OCBZ and phenobarbital, valproate, or carbamazepine were purely additive, either as regards the anticonvulsant activity against MES or in terms of motor impairment in the chimney test. Conclusions: The results of this study indicate that interaction of OCBZ and CZP at fixed-ratio combination of 1:1 might be profitable from a clinical point of view. Conversely, combinations of OCBZ with PHT may not be clinically efficient. [source] Postmarketing Surveillance of New Antiepileptic Drugs: The Tribulations of TrialsEPILEPSIA, Issue 9 2002Jacqueline A. French First page of article [source] Embryonic Arrhythmia by Inhibition of HERG Channels: A Common Hypoxia-related Teratogenic Mechanism for Antiepileptic Drugs?EPILEPSIA, Issue 5 2002Faranak Azarbayjani Summary: ,Purpose: There is evidence that drug-induced embryonic arrhythmia initiates phenytoin (PHT) teratogenicity. The arrhythmia, which links to the potential of PHT to inhibit a specific potassium channel (Ikr), may result in episodes of embryonic ischemia and generation of reactive oxygen species (ROS) at reperfusion. This study sought to determine whether the proposed mechanism might be relevant for the teratogenic antiepileptic drug trimethadione (TMO). Methods: Effects on embryonic heart rhythm during various stages of organogenesis were examined in CD-1 mice after maternal administration (125,1,000 mg/kg) of dimethadione (DMO), the pharmacologically active metabolite of TMO. Palatal development was examined after administration of a teratogenic dose of DMO and after simultaneous treatment with DMO and a ROS-capturing agent (,-phenyl- N -tert-butyl-nitrone; PBN). The Ikr blocking potentials of TMO and DMO were investigated in HERG-transfected cells by using voltage patch-clamping tests. Results: DMO caused stage-specific (gestation days 9,13 only) and dose-dependent embryonic bradycardia and arrhythmia at clinically relevant maternal plasma concentrations (3,11 mM). Hemorrhage in the nasopharyngeal part of the embryonic palate (within 24 h) preceded cleft palate in fetuses at term. Simultaneous treatment with PBN significantly reduced the incidence of DMO-induced cleft palate, from 40 to 13%. Voltage patch-clamping studies showed that particularly DMO (70% inhibition), but also TMO, had Ikr blocking potential at clinically relevant concentrations. Conclusions: TMO teratogenicity, in the same way as previously shown for PHT, was associated with Ikr -mediated episodes of embryonic cardiac arrhythmia and hypoxia/reoxygenation damage. [source] Antiepileptogenesis and Seizure Prevention Trials with Antiepileptic Drugs: Meta-Analysis of Controlled TrialsEPILEPSIA, Issue 4 2001Nancy R. Temkin Summary: ,Purpose: To synthesize evidence concerning the effect of antiepileptic drugs (AEDs) for seizure prevention and to contrast their effectiveness for provoked versus unprovoked seizures. Methods: Medline, Embase, and The Cochrane Clinical Trials Register were the primary sources of trials, but all trials found were included. Minimal requirements: seizure-prevention outcome given as fraction of cases; AED or control assigned by random or quasi-random mechanism. Single abstracter. Aggregate relative risk and heterogeneity evaluated using Mantel,Haenszel analyses; random effects model used if heterogeneity was significant. Results: Forty-seven trials evaluated seven drugs or combinations for preventing seizures associated with fever, alcohol, malaria, perinatal asphyxia, contrast media, tumors, craniotomy, and traumatic brain injury. Effective: Phenobarbital for recurrence of febrile seizures [relative risk (RR), 0.51; 95% confidence interval (CI), 0.32,0.82) and cerebral malaria (RR, 0.36; CI, 0.23,0.56). Diazepam for contrast media,associated seizures (RR, 0.10; CI, 0.01,0.79). Phenytoin for provoked seizures after craniotomy or traumatic brain injury (craniotomy: RR, 0.42; CI, 0.25,0.71; TBI: RR, 0.33; CI, 0.19,0.59). Carbamazepine for provoked seizures after traumatic brain injury (RR, 0.39; CI, 0.17,0.92). Lorazepam for alcohol-related seizures (RR, 0.12; CI, 0.04,0.40). More than 25% reduction ruled out valproate for unprovoked seizures after traumatic brain injury (RR, 1.28; CI, 0.76,2.16), and carbamazepine for unprovoked seizures after craniotomy (RR, 1.30; CI, 0.75,2.25). Conclusions: Effective or promising results predominate for provoked (acute, symptomatic) seizures. For unprovoked (epileptic) seizures, no drug has been shown to be effective, and some have had a clinically important effect ruled out. [source] Quality-of-Life and Behavioral Outcome Measures in Randomized Controlled Trials of Antiepileptic Drugs: A Systematic Review of Methodology and Reporting StandardsEPILEPSIA, Issue 11 2000Gus A. Baker Summary: Purpose: To review the methodology and use of quality-of-life and behavioral measures used in randomized controlled trials (RCTs) of antiepileptic drugs in patients with epilepsy. Methods: Trial reports were found by searching a previously developed comprehensive database of epilepsy RCTs and searching through journals by hand. Inclusion and exclusion criteria were applied, and methodological and quality-of-life and behavioral measure data were extracted. Results: There were 52 different measures used in 46 trials, with the Profile of Mood States, the Minnesota Multiphasic Personality Inventory, and the Washington Psychosocial Seizure Inventory being applied the most frequently. Overall, evidence of the reliability, validity, and sensitivity of measures used in populations of people with epilepsy was sparse. There was also little information on the clinical interpretation of the results. Conclusion: Our results highlight a consistent failure to apply quality-of-life and behavioral measures in RCTs in a systematic way. We found repeated evidence of researchers' failure to review the use of previous measures and selection of measures without evidence of their appropriateness for use in a population with epilepsy. We recommend the use of quality-of-life and behavioral measures in RCTs with proven psychometric properties in a population with 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] Antiepileptic Drugs in Migraine, Cluster Headache, and Mood DisordersHEADACHE, Issue 2001F. Michael Cutrer MD No abstract is available for this article. [source] Antiepileptic Drugs: How They Work in HeadacheHEADACHE, Issue 2001F. Michael Cutrer MD Antiepileptic drugs (AEDs) are promising agents for the prevention of migraine and other head pain. Migraine and epilepsy share several clinical features and respond to many of the same pharmacologic agents, suggesting that similar mechanisms may be involved in their pathophysiology. The mechanisms of action of AEDs are not fully understood, and a single drug may have more than one mechanism, both in epilepsy and in migraine. Valproate, topiramate, and gabapentin are likely to affect nociception by modulating gamma-aminobutyric acid- (GABA-) and/or glutamate-mediated neurotransmission. All three AEDs enhance GABA-mediated inhibition. Valproate and gabapentin interfere with GABA metabolism to prevent its ultimate conversion to succinate, and topiramate potentiates GABA-mediated inhibition by facilitating the action of GABA receptors. In addition, topiramate acts directly on non- N -methyl-D-aspartate, alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid/kainate glutamate receptors. Valproate, topiramate, and possibly gabapentin inhibit sodium ion channels. All three drugs modulate calcium ion channel activity. Valproate blocks T-type calcium ion channels; topiramate inhibits high-voltage-activated L-type calcium ion channels; and gabapentin binds to the ,2, subunit of L-type calcium ion channels. AEDs may be useful in migraine prevention through such mechanisms as modulating the biochemical phenomena of aura or acting directly on the nociceptive system. Further evaluations of AEDs in migraine models will provide a better understanding of the pathophysiology and prevention of migraine. [source] Antiepileptic Drugs in Migraine PreventionHEADACHE, Issue 2001Ninan T. Mathew MD Migraineurs may continue to experience attacks, despite daily use of one or more agents from a wide range of drugs, including , -blockers, calcium channel blockers, serotonin antagonists, tricyclic antidepressants, monoamine oxidase inhibitors, and antiepileptic agents. Divalproex sodium is the only antiepileptic drug approved for migraine prevention. Gabapentin, topiramate, and other antiepileptic agents are being evaluated for migraine prevention and treatment. Prospective, double-blind, placebo-controlled clinical trials of divalproex, gabapentin, and topiramate for migraine prevention generally were composed of a prospective baseline period, a dose titration period, and a fixed-dose treatment period. The primary efficacy variable was a reduction in the 28-day frequency of migraine headache. Patients receiving divalproex for 12 weeks at doses up to 1500 mg/day achieved significant decreases in the migraine frequency (P<.05), corresponding to reductions of 30% to 40% compared with baseline. Nearly half of the divalproex-treated patients had a 50% or more reduction from baseline in headache frequencies (P.05). Asthenia, vomiting, somnolence, tremor, and alopecia were common adverse events associated with divalproex. Significant reductions in migraine frequency were also observed with gabapentin (1800 to 2400 mg/day) when compared with placebo (P<.01), and nearly half of all patients treated at the highest dose experienced a reduction in headache rate of 50% or more. Somnolence was the most commonly reported adverse event among the gabapentin-treated patients. Two single-center, double-blind, placebo-controlled clinical trials evaluated topiramate for migraine prevention. A lower 28-day migraine frequency was seen during 18 weeks of administration at a maximum daily dose of 200 mg (P = .09). In a second study, a significantly lower mean 28-day migraine frequency was observed during 16 weeks of treatment with topiramate (P = .0015). Mean reduction in migraine frequency was also significantly greater in topiramate-treated patients (P = .0037). Paresthesias, diarrhea, somnolence, and altered taste were commonly reported adverse events in the topiramate-treated patients. Unlike some patients given divalproex or gabapentin, some given topiramate reported weight loss. Large, double-blind, placebo-controlled trials may prove the effectiveness of novel antiepileptic drugs in migraine prevention. [source] Antiepileptic Drugs in the Management of Cluster Headache and Trigeminal NeuralgiaHEADACHE, Issue 2001Todd D. Rozen MD Cluster headache and trigeminal neuralgia are relatively rare but debilitating neurologic conditions. Although they are clinically and diagnostically distinct from migraine, many of the same pharmacologic agents are used in their management. For many patients, the attacks are so frequent and severe that abortive therapy is often ineffective; therefore, chronic preventive therapy is necessary for adequate pain control. Cluster headache and trigeminal neuralgia have several distinguishing clinical features. Cluster headache is predominantly a male disorder; trigeminal neuralgia is more prevalent in women. Individuals with cluster headaches often develop their first attack before age 25; most patients with trigeminal neuralgia are between age 50 and 70. Cluster headaches are strongly associated with tobacco smoking and triggered by alcohol consumption; trigeminal neuralgia can be triggered by such stimuli as shaving and toothbrushing. Although the pain in both disorders is excruciating, cluster headache pain is episodic and unilateral, typically surrounds the eye, and lasts 15 to 180 minutes; the pain of trigeminal neuralgia lasts just seconds and is usually limited to the tissues overlying the maxillary and mandibular divisions of the trigeminal nerve. Cluster headache is unique because of its associated autonomic symptoms. Although the pathophysiology of cluster headache and trigeminal neuralgia are not completely understood, both appear to have central primary processes, and these findings have prompted investigations of the effectiveness of the newer antiepileptic drugs for cluster headache prevention and for the treatment of trigeminal neuralgia. The traditional antiepileptic drugs phenytoin and carbamazepine have been used for the treatment of trigeminal neuralgia for a number of years, and while they are effective, they can sometimes cause central nervous system effects such as drowsiness, ataxia, somnolence, and diplopia. Reports of studies in small numbers of patients or individual case studies indicate that the newer antiepileptic drugs are effective in providing pain relief for trigeminal neuralgia and cluster headache sufferers, with fewer central nervous system side effects. Divalproex has been shown to provide effective pain control and to reduce cluster headache frequency by more than half in episodic and chronic cluster headache sufferers. Topiramate demonstrated efficacy in a study of 15 patients, with a mean time to induction of cluster headache remission of 1.4 weeks (range, 1 day to 3 weeks). In the treatment of trigeminal neuralgia, gabapentin has been shown to be effective in an open-label study. When added to an existing but ineffective regimen of carbamazepine or phenytoin, lamotrigine provided improved pain relief; it also may work as monotherapy. Topiramate provided a sustained analgesic effect when administered to patients with trigeminal neuralgia. The newer antiepileptic drugs show considerable promise in the management of cluster headache and trigeminal neuralgia. [source] Antiepileptic Drugs in Migraine, Cluster Headache, and Mood DisordersHEADACHE, Issue 2001Article first published online: 31 MAR 200 No abstract is available for this article. [source] Antiepileptic drugs in the preventive treatment of migraine in children and adolescentsDRUG DEVELOPMENT RESEARCH, Issue 6 2007Catello Vollono Abstract Migraine prevalence in childhood ranges from 2.7 to 10% causing a significant impact on quality of life. No drugs are currently approved for use in the prevention of pediatric migraine. Antiepileptic drugs such as valproate and topiramate have been approved for the preventive treatment of migraine in adults. The present study aimed at reviewing evidence on the efficacy and safety of antiepileptic drugs in the preventive treatment of migraine in children and adolescents. We searched PubMed from 1988 to May 2007 and reviewed, abstracted, and classified relevant literature. Thirteen studies were reviewed. Data from randomized controlled trials are available only for valproate and topiramate. They show that both topiramate and valproate are effective in reducing headache frequency, intensity, and duration. As for safety and tolerability, topiramate is well tolerated, while there are insufficient data regarding the tolerability of valproate. Open-label or retrospective studies suggest that levetiracetam, zonisamide, and gabapentin are effective, but further evidence is warranted to confirm these data. Drug Dev Res 68:355,359, 2007. © 2007 Wiley-Liss, Inc. [source] Course and outcome of childhood epilepsy: A 15-year follow-up of the Dutch Study of Epilepsy in ChildhoodEPILEPSIA, Issue 7 2010Ada Geerts Summary Purpose:, To study the course and outcome of childhood-onset epilepsy during 15-year follow-up (FU). Methods:, We extended FU in 413 of 494 children with new-onset epilepsy recruited in a previously described prospective hospital-based study by questionnaire. Results:, Mean FU was 14.8 years (range 11.6,17.5 years). Five-year terminal remission (TR) was reached by 71% of the cohort. Course during FU was favorable in 50%, improving in 29%, and poor or deteriorating in 16%. Mean duration of seizure activity was 6.0 years (range 0,21.5 years), strongly depending on etiology and epilepsy type. Duration was <1 year in 25% of the cohort and exceeded 12 years in another 25%. Antiepileptic drugs (AEDs) were used by 86% during a mean of 7.4 years: one-third had their last seizure within 1 year of treatment, and one-third continued treatment at the end, although some had a 5-year TR. At last contact, 9% of the cohort was intractable. In multivariate analysis, predictors were nonidiopathic etiology, febrile seizures, no 3-month remission, and early intractability. Eighteen patients died; 17 had remote symptomatic etiology. Standardized mortality ratio for remote symptomatic etiology was 31.6 [95% confidence interval (CI) 18.4,50.6], versus 0.8 [95% CI 0.02,4.2] for idiopathic/cryptogenic etiology. Discussion:, In most children with newly diagnosed epilepsy, the long-term prognosis of epilepsy is favorable, and in particular, patients with idiopathic etiology will eventually reach remission. In contrast, epilepsy remains active in ,30% and becomes intractable in ,10%. AEDs probably do not influence epilepsy course; they merely suppress seizures. Mortality is significantly higher only in those with remote symptomatic etiology. [source] Antiepileptic drugs combined with high-frequency electrical stimulation in the ventral hippocampus modify pilocarpine-induced status epilepticus in ratsEPILEPSIA, Issue 3 2010Manola Cuellar-Herrera Summary Purpose:, To evaluate the effects of high-frequency electrical stimulation (HFS) in both ventral hippocampi, alone and combined with a subeffective dose of antiepileptic drugs, during the status epilepticus (SE) induced by lithium-pilocarpine (LP). Methods:, Male Wistar rats, stereotactically implanted in both ventral hippocampi, were injected with pilocarpine (30 mg/kg, i.p.) 24 h after lithium (3 mEq/kg) administration. One minute following pilocarpine injection, HFS (pulses of 60 ,s width at 130 Hz at subthreshold intensities and applied during 3 h) was applied alone or combined with subeffective doses of antiepileptic drugs. Results:, HFS alone reduced the incidence of severe generalized seizures. This effect was not evident when HFS was combined with phenytoin (33.3 mg/kg, i.p.). HFS combined with diazepam (0.41 mg/kg, i.p.) or phenobarbital (10 mg/kg, i.p.) reduced the incidence of severe generalized seizures and mortality rate, and augmented the latency to first forelimb clonus, generalized seizure, and status epilepticus (SE). When combined with gabapentin (46 mg/kg, i.p.), HFS reduced the incidence of severe generalized seizures, enhanced latency to SE, and decreased mortality rate. Discussion:, Subeffective doses of antiepileptic drugs that increase the ,-aminobutyric acid (GABA)ergic neurotransmission may represent a therapeutic tool to augment the HFS-induced anticonvulsant effects. [source] Antiepileptic drugs in children in developing countries: Research and treatment guideline needsEPILEPSIA, Issue 11 2009Mina Farkhondeh Summary Epilepsy is the most common neurologic disorder in childhood. Effective interventions are available for treatment; however, the treatment gap in children is more than 80% in many developing countries. An important reason for this huge treatment gap is limited access to antiepileptic drugs (AEDs). This article discusses the reasons for such a treatment gap, and possible ways forward in improving care of children with epilepsy worldwide. [source] | |||||||||||||||||||||||||||||||