Acute effects of lamotrigine (BW430C) in persons with epilepsy

Sixteen epileptic patients took single doses of lamotrigine, 120 mg or 240 mg. Six photosensitive patients showed reduction (with abolition in two) in photosensitivity after lamotrigine administration. Five subjects with frequent interictal spikes showed reduction in spike frequency over 24 h after lamotrigine administration. The half-life (t1/2) of lamotrigine in subjects taking sodium valproate was prolonged, whereas the t1/2 in subjects taking carbamazepine and/or phenytoin was reduced. The area under the curve of co-medication plasma levels was not affected by a single dose of lamotrigine. Five patients reported mild and generally transitory side effects; some of which represented exacerbation of preexisting complaints.     

Antiepileptic drug treatment in the nineties in The Netherlands.

In this review the state of the art of treating patients with epilepsy in the nineties in the Netherlands is presented. It describes general strategies for treatment with antiepileptic drugs and the history of development of the classical anticonvulsant drugs. Eight new drugs, including vigabatrin, lamotrigine, felbamate, oxcarbazepine, gabapentin, tiagabine, levetiracetam and topiramate are discussed. A review of their pharmacological and clinical properties is presented. Dutch experience with these drugs is included.     

Effect of carbamazepine, oxcarbazepine and lamotrigine on the increase in extracellular glutamate elicited by veratridine in rat cortex and striatum

Lamotrigine, carbamazepine and oxcarbazepine inhibit veratrine-induced neurotransmitter release from rat brain slices in concentrations corresponding to those reached in plasma or brain in experimental animals or humans after anticonvulsant doses, presumably due to their sodium channel blocking properties. Microdialysis measurements of extracellular glutamate and aspartate were carried out in conscious rats in order to investigate whether corresponding effects occur in vivo. Veratridine (10 M) was applied via the perfusion medium to the cortex and the corpus striatum in the presence of the glutamate uptake inhibitor L-trans-pyrrolidine-2,4-dicarboxylic acid (1 mM in perfusion medium). Maximally effective anticonvulsant doses of carbamazepine (30 mg/kg), oxycarbazepine ( 60 mg/kg) and lamotrigine (15 mg/kg) were given orally.The uptake inhibitor increased extracellular glutamate and aspartate about 2-fold in striatum and about 7-fold and 3-fold, respectively, in cortex. Veratridine caused a further 2–3-fold increase in extracellular glutamate in striatum and cortex, respectively, but its effect on extracellular aspartate was less marked in both areas. None of the anticonvulsant compounds affected the veratridine-induced increases in extracellular glutamate or aspartate in the striatum which were, however, markedly inhibited by tetrodotoxin (1 M) and thus are sensitive to sodium channel blockade. In the cortex, the same drugs at the same doses did cause about 50% inhibition of the veratridine-induced increase in extracellular glutamate. Carbamazepine and to a lesser extent lamotrigine, but not oxcarbazepine, also inhibited the veratridine-induced increase in extracellular aspartate in the cortex.Although our results might seem to support the view that inhibition of glutamate and aspartate release is responsible for the anticonvulsant effects of lamotrigine, carbamazepine and oxcarbazepine, two complementary findings argue against this interpretation. First, as previously shown, inhibition of electrically induced release of glutamate requires 5 to 7 times higher concentrations of these compounds than release elicited by veratrine. Second, the present study indicates that doses totally suppressing convulsions caused no inhibition in the striatum and at best a 50% inhibition in the brain cortex. From this we conclude that the doses used here, although to some extent effective against veratridine, did not suppress the release of GLU and ASP elicited by the normal ongoing electrical activity of the glutamatergic and aspartatergic neurons and that the mechanism of the suppression of convulsions must be sought elsewhere.     

拉莫三嗪治疗癫痫的剂量及血药浓度

目的:研究拉莫三嗪治疗癫痫的有效血药浓度、剂量与疗效三者之间关系以及和/或丙戊酸等其它抗癫痫药合用时的相互影响。方法:83例患者分为3组,即拉莫三嗪组、拉莫三嗪+丙戊酸组及拉莫三嗪+丙戊酸+其它抗癫痫药组。拉莫三嗪的起始剂量拉莫三嗪组为2mg/(kg·d),联合用药组为0.2mg/(kg·d),丙戊酸成人起始剂量为负荷量。结果:联合用药组中的部分病例拉莫三嗪剂量高于国外推荐剂量。当拉莫三嗪剂量在2～7mg/kg、血药浓度在1～6mg/L,丙戊酸的剂量在4～28.19mg/kg、血药浓度在37.46～113.79mg/L时,癫痫有效控制率在67.6％～86.4％之间。结论:国外推荐的拉莫三嗪有效血药浓度及与其它抗癫痫药合用时的剂量可能偏低。     

Rectal absorption of lamotrigine compressed tablets

PURPOSE: Interruption of oral drug administration poses a significant clinical problem for antiepileptic drugs that have no parenteral formulation. If a drug is absorbed rectally, rectal administration can be a useful alternative when the oral route of administration is not possible. The purpose of this study was to compare the single-dose pharmacokinetics of lamotrigine (LTG) compressed tablets after rectal and oral administration in healthy volunteers. METHODS: A single LTG compressed tablet (100 mg) was administered orally and rectally to 12 volunteers in this single-dose, two-period, crossover study with a 2-week washout between doses. For rectal administration, tablets were crushed and suspended in 10 mL of water. Plasma samples were collected from 0 to 120 hr after each dose and analyzed for LTG by an HPLC method developed for this investigation. RESULTS: LTG plasma concentrations were lower after rectal administration versus oral administration. The average area under the curve was 28.90 +/- 9.5 microg/mL/hr after rectal administration and 51.71 +/- 19.2 microg/mL/hr after oral administration. The average maximum LTG concentration was 0.53 +/- 0.14 microg/mL after rectal administration and 1.45 +/- 0.35 microg/mL after oral administration. The relative bioavailability for LTG compressed tablets was 0.63 +/- 0.33 for rectal administration. There were no drug-related rashes or serious side effects. CONCLUSIONS: LTG suspension prepared from LTG compressed tablets is absorbed rectally, although not to the same extent or rate as when given orally.     

Lamotrigine-induced tic disorder: report of five pediatric cases

PURPOSE: To describe the clinical spectrum of lamotrigine (LTG)-induced tics (an uncommon side effect) in children. METHODS: Retrospective analysis of patients from our hospital-based practice who developed tics while on LTG. Data obtained from medical records, interviews with parents, video-EEGs, and homemade videotapes. RESULTS: Three males and two females (range, 2.5-12 years; mean, 6.9 years) developed a movement disorder within the first 10 months of therapy (maintenance doses, 4-17 mg/kg/day). Four patients exhibited simple motor tics; one patient experienced mostly vocal (i.e., gasping sounds) tics. Laryngoscopic evaluation of one 2.5-year-old with repetitive gasping sounds was normal. In three cases, tics resolved completely within 1 month of drug cessation; tics recurred in two of these patients after reintroduction of LTG. A fourth patient experienced gradual improvement after stopping LTG over 4 months; the fifth patient's simple motor tics improved spontaneously with a reduction in medication. None of the patients had clinical features of a neurodegenerative disorder, and none met diagnostic criteria for Tourette syndrome. Two patients, however, had a diagnosis of acquired epileptic aphasia syndrome, and one patient had nonprogressive expressive and receptive language dysfunction. A fourth patient had global static encephalopathy, and the fifth patient had only attentional problems. In all patients, tics were not associated with ictal EEG changes. CONCLUSIONS: LTG may infrequently induce simple motor tics, vocal tics, or both. Patients with severe language dysfunction may be particularly susceptible to this uncommon side effect. Further studies are necessary to clarify the population at risk.     

Efficacy and tolerability of lamotrigine in Juvenile Myoclonic Epilepsy in adults: A prospective,unblinded randomized controlled trial

PurposeControlled randomized studies recommending the clinical use of lamotrigine in adult populations with the diagnosis of Juvenile Myoclonic Epilepsy are still lacking. To compare the efficacy and tolerability of lamotrigine versus valproate in adult patients with JME.MethodsThis was a prospective, randomized, controlled, pragmatic, long-term and open-label treatment trial. Patients were randomized to use valproate or lamotrigine. The primary end points of the study were: (1) time from randomization to treatment failure (withdrawal); (2) time from randomization to seizures remission. Secondary ending points were: (1) frequency of clinically important adverse events and (2) change in the QOLIE-31 after randomization. The definition of seizure remission was based on disappearance of all seizure types and EEG discharges.ResultsWe found that the time to withdraw treatment after randomization was not significantly different in lamotrigine and valproate groups. Long-term seizures freedom was equal in the both groups of the trial; only 8 (19.1%) patients randomized to lamotrigine and 6 (19.4%) randomized to valproate were not seizure free after 4 months of treatment. Between 17.03% (lamotrigine) and 35.3% (valproate) of patients reported adverse reactions at some point in the intention-to treat study (p = 0.07). All subscales of the QOLIE-31 questionnaire, except that related to side effects of medication, improved more than 5 points with respect to baseline period in both groupsConclusionLamotrigine is effective in adult patients with Juvenile Myoclonic Epilepsy and better tolerated than valproate, although the incidence of idiosyncratic reactions could be a cause of concern.     

拉莫三嗪与奥卡西平单药治疗成人新诊断局灶性癫痫的长期疗效及安全性比较

目的 比较拉莫三嗪(LTG)和奥卡西平(OXC)单药治疗成人新诊断局灶性癫痫的长期疗效、耐受性和安全性。方法 收集本院癫痫专病门诊新诊断的局灶性癫痫,随机分成OXC组和LTG组,根据临床情况调整剂量,OXC最大剂量1200 mg/d,LTG最大剂量300 mg/d,至少随访3年,评估二种药物单药治疗成人新诊断局灶性癫痫无发作率、保留率及不良反应。结果 2009年6月-2016年6月符合入组标准146例,其中OXC组74例,LTG组72例,2组1年无发作率分别为35.1%和51.3%(χ2=3.9,P=0.047),3年无发作率分别为21.6%和40.2%(χ2=5.96,P=0.015),LTG组总体无发作率高于OXC组(P<0.05); OXC组和LTG组1年保留率分别为59.5%和69.4%(χ2=1.59,P=0.208),3年保留率分别为44.6%和51.4%(χ2=0.68,P=0.411),LTG组总体保留率亦高于OXC组,但无明显差异(P>0.05)。OXC组和LTG组最常见的不良反应均为皮疹(6.8% vs. 8.3%)。结论 LTG单药治疗新诊断成人局灶性癫痫的长期无发作率高于OXC,两者不良反应较轻,有较好的安全性。