Lamotrigine in add-on therapy: assessment of efficacy in drug resistant epilepsy

The authors presented the results of treatment with lamotrigine (LTG, Lamictal) in 13 patients with drug resistant epilepsy (add-on therapy). There were 8f, 5m. aged 16-60 years, mean age 28.8 years. Generalized seizures occurred in 8 patients (62%). In this group there was 1 patient (aged 16 years) with the Lennox-Gastaut syndrome and 1 patient (aged 20 years) with valproate resistant juvenile myoclonic epilepsy. Complex partial seizures and complex partial with secondary generalization occurred in 5 patients (38%). Before LTG addition mean seizure frequency was from 3/month to several times/day. The mean duration of epilepsy was 16.6 years. The 8 patients were treated with CBZ and VPA, one with PHT and VPA, one CBZ and VGB. Monotherapy with VPA was introduced in 3 patients. After 6 months of treatment with LTG the efficacy was evaluated. 12 patients took LTG with VPA, 1 LTG with CBZ. Complete reduction of seizures was achieved in 3 cases (23%), at least 50% reduction in 3 patients (23%), reduction below 50% in 4 patients (31%). In 3 cases (23%) the results of treatment were negative (increase or no change in seizure frequency). Beneficial psychotropic effect was observed in 9 patients (69%). Adverse effects occurred in 2 patients (15%). Headache, vertigo, sleepness were observed in one case. Rash occurred in 1 patient (treated with LTG and VPA). After 6 months 3 patients were excluded from the study because of negative effects of treatment. LTG is helpful and well tolerated in drug-resistant epilepsy.     

Therapeutic drug monitoring of lamotrigine in patients suffering from resistant partial seizures

Sixty patients, all potential candidates for ongoing lamotrigine (LTG) treatment as add-on therapy for resistant partial seizures and receiving carbamazepine (CBZ) and/or valproate (VPA) treatment, were submitted to therapeutic drug monitoring (TDM). The aim was to evaluate the possible relation between serum levels and the clinical effect of LTG, to verify whether CNS toxicity has to be considered the result of a pharmacokinetic or a pharmacodynamic interaction with CBZ, and to investigate whether possible changes in the clinical response during long-term treatment are dependent on LTG serum level variations. Sixteen patients achieved complete control, 26 a >or=50% reduction in seizures, the remainder did not respond. Mean LTG serum concentrations were higher in responders than in nonresponders, the difference being statistically insignificant. The best results were observed in VPA-cotreated patients with the highest LTG blood levels. CNS toxicity occurred after giving LTG to subjects who subsequently developed the highest LTG concentrations, whereas CNS toxicity seemed unrelated to CBZ and CBZ-epoxide serum concentrations. No decrease in LTG, CBZ and VPA serum levels was observed even in patients showing a reduction in the response during long-term treatment.     

The Efficacy of Valproate-Lamotrigine Comedication in Refractory Complex Partial Seizures: Evidence for a Pharmacodynamic Interaction

PURPOSE: To assess the comparative therapeutic value of valproate (VPA), lamotrigine (LTG), and their combination in patients with complex partial seizures resistant to other established antiepileptic drugs (AEDs). METHODS: After a 3-month prospective baseline, 20 adults with refractory complex partial seizures not exposed previously to VPA and LTG were scheduled to receive three consecutive add-on treatments with VPA, LTG, or their combination, according to an open, response-conditional, crossover design. Each period consisted of a 6- to 12-week dose optimization followed by 3-month evaluation at stabilized serum drug levels. Only patients not responding to one phase proceeded to the next. RESULTS: A >50% reduction in seizure frequency was observed in three of 20 patients given VPA and in four of 17 patients given LTG. Of the remaining 13 patients, four became seizure free, and an additional four experienced seizure reductions of 62-78% when VPA and LTG were given in combination. Mild tremor was observed in three patients receiving VPA and in all patients taking the VPA--LTG combination. In patients responding to combination therapy, optimized dosages and peak serum levels of both VPA and LTG were lower than those during separate administration. CONCLUSIONS: A considerable proportion of patients who failed to respond to VPA and LTG separately improved when the two drugs were combined, although serum levels of both agents were lower during combination therapy. Despite methodologic limitations in the nonrandomized treatment sequence, these findings suggest that VPA and LTG exhibit a favorable pharmacodynamic interaction in patients with refractory partial epilepsy. The dosage of both drugs, however, may need to be reduced to minimize the risk of intolerable side effects.     

The LAM-SAFE Study: Lamotrigine versus carbamazepine or valproic acid in newly diagnosed focal and generalised epilepsies in adolescents and adults

OBJECTIVE: To investigate efficacy and safety of lamotrigine (LTG) versus carbamazepine (CBZ) or valproic acid (VPA) in newly diagnosed focal (FE) and idiopathic generalised (GE) epilepsies in adolescents and adults. METHODS: Open-label randomised comparative multicentre 24-week monotherapy trial in newly diagnosed epilepsy patients of >or=12 years of age. Patients with FE were treated with LTG or CBZ, those with GE received LTG or VPA. The primary efficacy variable was the number of seizure-free patients during study weeks 17 and 24. RESULTS: Two hundred and thirty-nine patients were included. One hundred and seventy-six patients suffered from FE and 63 from GE. In the FE group, 88 patients each were treated with CBZ or LTG. Ninety-four percent of the CBZ patients and 89% of the LTG patients became seizure-free according to an intent-to-treat analysis (not statistically different). The rate of patients discontinuing treatment due to adverse events or a lack of efficacy was 19% with CBZ compared to 9% with LTG (not statistically different). In the GE group, 30 patients received VPA and 33 LTG. During study weeks 17 and 24, 61% of the LTG patients and 84% of the VPA patients had become seizure-free (not statistically significant). The drop-out rate due to lack of efficacy or adverse events was 12% with LTG and 3% with VPA (not statistically different). CONCLUSIONS: This study indicates that the effectiveness of LTG in focal and generalised epilepsy syndromes as initial monotherapy in patients >or=12 years is in the range of standard first-line antiepileptic drugs.     

Pregabalin drug interaction studies: lack of effect on the pharmacokinetics of carbamazepine, phenytoin, lamotrigine, and valproate in patients with partial epilepsy

PURPOSE: Pregabalin (PGB) is an alpha2-delta ligand with demonstrated efficacy in epilepsy, neuropathic pain, and anxiety disorders. PGB is highly efficacious as adjunctive therapy in patients with refractory partial seizures. METHODS: Given its efficacy as adjunctive therapy, the potential for interaction of PGB with other antiepileptic drugs (AEDs) was assessed in patients with partial epilepsy in open-label, multiple-dose studies. Patients received PGB, 600 mg/day (200 mg q8h) for 7 days, in combination with their individualized maintenance monotherapy with valproate (VPA), phenytoin (PHT), lamotrigine (LTG), or carbamazepine (CBZ). RESULTS: Trough steady-state concentrations of CBZ (and its epoxide metabolite), PHT, LTG, and VPA were unaffected by concomitant PGB administration. Likewise, PGB steady-state pharmacokinetic parameter values were similar among patients receiving CBZ, PHT, LTG, or VPA and, in general, were similar to those observed historically in healthy subjects receiving PGB alone. The PGB-AED combinations were generally well tolerated. PGB may be added to VPA, LTG, PHT, or CBZ therapy without concern for pharmacokinetic drug-drug interactions.     

Effect of antiepileptic drugs on spontaneous seizures in epileptic rats

The present study investigated whether spontaneously seizing animals are a valid model for evaluating antiepileptic compounds in the treatment of human epilepsy. We examined whether clinically effective antiepileptic drugs (AEDs), including carbamazepine (CBZ), valproic acid (VPA), ethosuximide (ESM), lamotrigine (LTG), or vigabatrin (VGB) suppress spontaneous seizures in a rat model of human temporal lobe epilepsy, in which epilepsy is triggered by status epilepticus induced by electrical stimulation of the amygdala. Eight adult male rats with newly diagnosed epilepsy and focal onset seizures were included in the study. Baseline seizure frequency was determined by continuous video-electroencephalography (EEG) monitoring during a 7 days baseline period. This was followed by a 2-3 days titration period, a 5-7 days treatment period, and a 2-3 days wash-out period. During the 5-7 days treatment period, animals were treated successively with CBZ (120 mg/kg/day), VPA (600 mg/kg/day), ESM (400 mg/kg/day), LTG (20 mg/kg/day), and VGB (250 mg/kg/day). VPA, LTG, and VGB were the most efficient of the compounds investigated, decreasing the mean seizure frequency by 83, 84, and 60%, respectively. In the VPA group, the percentage of rats with a greater than 50% decrease in seizure frequency was 100%, in the LTG group 88%, in the VGB group 83%, in the CBZ group 29%, and in the ESM group 38%. During the 7 day treatment period, 20% of the VPA-treated animals and 14% of the CBZ-treated animals became seizure-free. These findings indicate that rats with focal onset spontaneous seizures respond to the same AEDs as patients with focal onset seizures. Like in humans, the response to AEDs can vary substantially between animals. These observations support the idea that spontaneously seizing animals are a useful tool for testing novel compounds for the treatment of human epilepsy.     

Lamotrigine versus vigabatrin as an add-on therapy in refractory epilepsy: prospective study

Lamotrigine (LTG) and Vigabatrin (VGB) has been licensed widely as adjunctive therapy for partial and secondary generalized seizures. We compared the efficiency of Lamotrigine and Vigabatrin as adjuvant therapy for 33 patients (16 male and 17 female) with drug-resistant partial epileptic seizures (simple and complex) with secondary generalization receiving combination therapy (carbamazepine--CBZ and valproic acid--VPA). Patients were enrolled if they had experienced two partial seizures (simple or complex) and one secondary generalization/month, despite combination therapy. Neurologic evaluation including CT, MRI and EEG was performed every 3 months during observation. Blood specimens for CBZ and VPA plasma concentration were obtained prior to the first LTG or VGB dose and twice a year during the treatment. The assessment of LTG and VGB effectiveness was performed in 2-month intervals during 2-3 years for vigabatrin (mean daily dose 2.0 g) and 1-2 years for Lamotrigine (mean daily dose 0.3 g). The treatment (CBZ, VPA or both) with Vigabatrin or Lamotrigine as adjunctive therapy was effective in about a half of patients with refractory epilepsy. Findings suggest that the reduction in partial seizures (simple or complex) frequency with Vigabatrin is greater than that with Lamotrigine. On the other hand, Lamotrigine seems to be more effective in patients with partial epileptic seizures with secondary generalization.     

Effectiveness of First Antiepileptic Drug

PURPOSE: To investigate the interaction among efficacy, tolerability, and overall effectiveness of the first antiepileptic drug (AED) in patients with newly diagnosed epilepsy. METHODS: The 470 patients were diagnosed, treated and followed up from January 1984 at a single center. Outcome was classified as seizure freedom for at least the last year or failure of initial treatment because of inadequate seizure control, adverse events, or for other reasons. RESULTS: Overall, 47% of patients became seizure-free with the first prescribed AED. A higher proportion (p = 0.025) of patients with symptomatic or cryptogenic epilepsy changed treatment because of intolerable side effects (17%), and a lower proportion (p = 0.007) became seizure-free (43.5%) compared with those with idiopathic epilepsy (8.5% and 58%, respectively). Most patients (83%) received carbamazepine (CBZ; n = 212), sodium valproate (VPA; n = 101), or lamotrigine (LTG; n = 78). The majority of seizure-free patients required only a moderate daily AED dose (93.1% with < or =800 mg CBZ, 91.3% with < or =1,500 mg VPA, 93.8% with < or =300 mg LTG), with commonest dose ranges being 400-600 mg for CBZ, 600-1,000 mg for VPA, and 125-200 mg for LTG. Most withdrawals due to poor tolerability also occurred at or below these dose levels (CBZ: 98%; VPA: 100%; LTG: 75%). Patients taking CBZ (27%) had a higher incidence of adverse events necessitating a change of treatment than did those treated with VPA (13%) or LTG (10%), resulting in fewer becoming seizure-free (CBZ vs. VPA, p = 0.02; CBZ vs. LTG, p = 0.002). CONCLUSIONS: Nearly 50% of newly diagnosed patients became seizure-free on the first-ever AED, with >90% doing so at moderate or even modest dosing. Tolerability was as important as efficacy in determining overall effectiveness.     

Association between antiepileptic drug dose and long-term response in patients with refractory epilepsy

Seizures in patients with medically refractory epilepsy remain a substantial clinical challenge, not least because of the dearth of evidence-based guidelines as to which antiepileptic drug (AED) regimens are the most effective, and what doses of these drugs to employ. We sought to determine whether there were regions in the dosage range of commonly used AEDs that were associated with superior efficacy in patients with refractory epilepsy. We retrospectively analyzed treatment records from 164 institutionalized, developmentally disabled patients with refractory epilepsy, averaging 17 years of followup per patient. We determined the change in seizure frequency in within-patient comparisons during treatment with the most commonly used combinations of 12 AEDs, and then analyzed the response to treatment by quartile of the dose range for monotherapy with carbamazepine (CBZ), lamotrigine (LTG), valproate (VPA), or phenytoin (PHT), and the combination LTG/VPA. We found that of the 26 most frequently used AED regimens, only LTG/VPA yielded superior efficacy, similar to an earlier study. For the monotherapies, patients who were treated in the lowest quartile of the dose range had significantly better long-term reduction in seizure frequency compared to those treated in the 2nd and 3rd quartiles of the dose range. Patients with paired exposures to CBZ in both the lowest quartile and a higher quartile of dose range experienced an increase in seizure frequency at higher doses, while patients treated with LTG/VPA showed improved response with escalation of LTG dosage. We conclude that in this population of patients with refractory epilepsy, LTG/VPA was the most effective AED combination. The best response to AEDs used in monotherapy was observed at low dosage. This suggests that routine exposure to maximally tolerated AED doses may not be necessary to identify those patients with drug-resistant seizures who will have a beneficial response to therapy. Rather, responders to a given AED regimen may be identified with exposure to low AED doses, with careful evaluation of the response to subsequent titration to identify non-responders or those with exacerbation of seizure frequency at higher doses.     

A Pharmacoepidemiologic Study of Factors Influencing the Outcome of Treatment with Lamotrigine in Chronic Epilepsy

PURPOSE: To identify prognostic factors for freedom from seizures and long-term retention of treatment in patients receiving lamotrigine (LTG). METHODS: A multicenter, retrospective, case record study of 1,050 patients with chronic epilepsy was carried out. Logistic regression and Cox regression analyses were used to identify clinical features associated with freedom from seizures and retention of treatment, respectively. Long-term retention rates of LTG therapy were estimated using Kaplan-Meier survival analysis. RESULTS: The 1,050 patients with chronic epilepsy were included in the study. Patients with generalized epilepsy (p = 0.01), who were not receiving carbamazepine (CBZ; p = 0.02) were more likely to become seizure-free. Sixty percent of patients continued on LTG therapy >1 year and estimated retention at 8 years was 38%. Patients with generalized epilepsy (p = 0.002), patients receiving concurrent sodium valproate (VPA; p < 0.0001), those not previously exposed to gabapentin and vigabatrin (p < 0.0001), and those in whom the starting dose was lower (p < 0.0012), were more likely to remain on long-term treatment with LTG. The relationships with exposure to other antiepileptic drugs remained significant in patients with focal and with generalized epilepsy when considered separately. CONCLUSIONS: The best results from LTG treatment in terms of freedom from seizures and long-term retention of treatment were obtained in patients with generalized epilepsy. Retention of treatment was enhanced by VPA not only in generalized but also in focal epilepsy. The importance of a low starting dose of LTG was again confirmed. The apparent negative effect of CBZ in patients taking LTG merits further investigation.     

Pharmacokinetic Interactions Between Lamotrigine and Other Antiepileptic Drugs in Children with Intractable Epilepsy

Summary: Purpose : We wished to determine the oral pharmacokinetics of lamotrigine LTG and to assess possible interactions with other AEDs in an unselected population of children. Concentration data in plasma and in CSF for lamotrigine as well as for the other AEDs are presented.
Methods : Thirty-one children, children and young adults aged > 2 years with intractable generalized epilepsy despite adequate duration and dose of at least three conventional AEDs were studied.
Results : There was a linear relation between the dose administered and the maximal plasma concentration, indicating that saturation of absorption or elimination mechanisms did not occur in the dose range studied. The median elimination half-life (t1/2) in patients receiving concomitant valproate (VPA) was 43.3 h; in patients receiving carbamazepine (CBZ) and/or phenobarbital (PB), it was 14.1 h; and in patients receiving both VPA and CBZI PB or other antiepileptic drugs (AEDs), it was 28.9 h. No clinically important changes in the plasma levels of CBZ, VPA, valproate, ethosuximide, or PB were observed in the follow-up period (2–12 months). No dose adjustments of concomitant AEDs were necessary. The plasma concentration of clonazepam (CZP) was reduced when LTG was introduced.
Conclusions : The complex interaction between LTG and other AEDs in children with intractable epilepsy makes therapeutic drug monitoring (TDM) desirable.     

Concomitant use of divalproex sodium and lamotrigine in developmentally disabled patients with epilepsy: a retrospective evaluation of efficacy and tolerability

Objective. Epilepsy in institutionalized severe developmentally disabled patients poses a therapeutic challenge. Frequently these patients have multiple seizure (sz) types that are often intractable. Both divalproex sodium (VPA) and lamotrigine (LTG) have demonstrated efficacy. We sought to examine the efficacy of this specific combination in a group of institutionalized, developmentally disabled patients with epilepsy.Methods. Medical and pharmacy records of all patients with developmental disabilities and intractable seizures were reviewed to identify those who had received VPA and LTG. This retrospective evaluation was structured with respect to time frame and outcome measure. Phase 1 consisted of baseline monotherapy with VPA. Phase 2 consisted of titration/dose escalation. Phase 3 was treatment observation period with the combination of both. Seizure frequency and adverse effect data were obtained from nursing or residential staff records. Primary outcome measures were change in seizure frequency between Phases 1 and 3. Additional measures were percentage of patients seizure-free and those with >75% reduction in seizures. A Wilcoxan signed rank test was used for statistical analysis.Results. Of 293 patients, 25 (12M/13F, 31.7+/-10.2 years) had VPA monotherapy following which LTG was added. Mean doses of VPA and LTG were 1474+/-728 and 165+/-111mg/day, respectively. Baseline seizure frequency ranged from 1 to 25 per month. Mean seizure frequency significantly decreased (6.5+/-vs2.0+/-4.0seizures/month, P<0.001). Sixty-four percent of these patients had >/=75% reduction in seizures 28% became seizure-free.Conclusions. The combination of VPA and LTG appears efficacious in this group of developmentally disabled patients with intractable seizures. Rash, which has been associated with this combination, was notably absent and this may reflect the slower titration schedule used.     

Double-blind substitution of vigabatrin and valproate in carbamazepine-resistant partial epilepsy. 012 Study group

Patients from 12 countries reporting two or more partial seizures per month despite treatment with optimal doses of CBZ were randomised to additional vigabatrin (VGB, 2-4 g daily) or sodium valproate (VPA, 1-2 g daily) using a double-blind, double-dummy design. The study included a 6 month retrospective baseline on unchanged CBZ dosage, a month's prospective baseline, a short titration phase, and an assessment period lasting 3 months on duotherapy. CBZ was withdrawn over a further 2 months in responders ( > or = 50% monthly seizure reduction compared with baseline), who continued on alternative monotherapy for 3 or more months. If seizure control deteriorated, CBZ was reinstated and these patients were also followed up for 3 months. A total of 215 patients (108 VGB, 107 VPA) reporting a mean of seven partial seizures per month fulfilled the criteria for the intention-to-treat analysis. 53 and 51% of patients in the VGB and VPA group respectively achieved a monthly reduction in seizure numbers > or = 50%, respectively. 27 and 31% maintained alternative monotherapy. Overall, 17% (7% monotherapy, 10% duotherapy) of the VGB treated patients and 19% (8% monotherapy, 11% duotherapy) of the VPA group remained seizure-free during the final 3 month treatment period. VGB and VPA, which increase neuronal inhibition mediated by gamma aminobutyric acid, can be added to or substituted for CBZ when this Na+ channel blocker fails to control partial seizures. This lends credence to the hypothesis in support of a mechanistic approach to the management of epilepsy.     

Lack of an effect of valproate concentration on lamotrigine pharmacokinetics in developmentally disabled patients with epilepsy

PURPOSE: to describe the population pharmacokinetics of lamotrigine (LTG) in developmentally disabled (DD) patients with epilepsy and (2) to determine if there is an effect of valproate (VPA) concentration on the extent of the pharmacokinetic interaction between VPA and LTG. METHOD: a NONMEM population analysis of steady-state LTG serum concentrations was conducted in patients receiving LTG either as mono or polytherapy with either an enzyme inducer (IND)-carbamazepine (CBZ), phenytoin (PHT), phenobarbital (PB) or an inhibitor (VPA). RESULTS: sixty-two patients (33.6+/-11.3 years, 47+/-9.9 kg) receiving LTG monotherapy (n=19) or polytherapy with VPA (n=15), inducer(s) (n=32) or both (n=5) were evaluated. LTG dose of 369+/-236 mg per day (8.1+/-5.9 mg/kg per day) achieved LTG plasma concentrations of 6.8+/-3.3 microg/ml. The observed LTG monotherapy, LTG+IND, and LTG+VPA oral clearance (Cl/F) were 0. 69+/-0.2, 1.60+/-0.65 and 0.2+/-0.05 ml/kg per min, respectively. The final LTG Cl/F model was dependent on body weight, concomitant VPA, and either single or multiple inducers. Including the serum concentrations of CBZ, PHT, or VPA in the model, did not significantly improve estimates of Cl/F. CONCLUSION: LTG Cl/F in DD patients is similar to literature values for ambulatory adult patients; however, low weight adult patients have higher elimination rates, as well as an increased response to enzyme induction. VPA inhibition of LTG Cl/F is maximal within the usually accepted therapeutic range for VPA.     

Efficacy and tolerability of antiepileptic drugs in an Omani epileptic population

OBJECTIVE: The aim of this hospital-based study is to get an insight into the efficacy and tolerability of antiepileptic drugs (AED) in Omani epileptic patients. PATIENTS AND METHODS: All Omani patients (aged 14 years and above) suffering from epileptic seizures for at least 2 years and followed-up by board-certified neurologists in Sultan Qaboos University Hospital (SQUH) were evaluated. The treatment retention rate since first visit at SQUH and over the last 2 years was used as primary efficacy measure of AED therapy. Change in seizure-frequency and side effect profiles were also assessed. RESULTS: In this population of 203 confirmed epileptic patients, generalized tonic-clonic (40%) and partial seizures (39%) were most commonly observed, idiopathic/cryptogenic origin (81%) being the most frequent encountered origin. Sixty one percent of the patients were controlled with an AED in monotherapy and overall 34% of patients could be successfully maintained on monotherapy during the whole follow-up period at SQUH (median 6 years). The treatment retention rates for carbamazepine (CBZ) at a daily dose of 400-600 mg, sodium valproate (VPA) at a daily dose of 500-1000 mg, and phenytoin (PHT) at a daily dose of 300 mg, in monotherapy over the total follow-up period was 51, 50, and 21%, respectively. In contrast, over the last 2 years these rates were highest for VPA (91%) followed by CBZ (83%) and PHT (73%). Adverse drug reactions were recorded in 67% of patients, and were most commonly encountered with VPA. CONCLUSIONS: Despite a higher adverse effect profile for VPA, long-term treatment with CBZ and VPA appeared to be equally effective in terms of treatment retention rates and seizure control.     

Pharmacological outcomes in newly diagnosed epilepsy

The response to antiepileptic drugs (AEDs) has been examined in 780 adult and adolescent patients with newly diagnosed epilepsy presenting with a range of seizure types and epilepsy syndromes over a 20-year period. Carbamazepine (CBZ, n=312), sodium valproate (VPA, n=315), and lamotrigine (LTG, n=249) were the most common AEDs prescribed as monotherapy. More patients with localization-related epilepsies became seizure free with LTG (63%) than with CBZ (45%, P=0.006) or VPA (42%, P=0.006). For idiopathic generalized epilepsies a greater proportion of patients achieved control with VPA (68%) than with CBZ (31%) or LTG (45%). In particular, more patients with juvenile myoclonic epilepsy responded to VPA (75%) compared with LTG (39%, P=0.014). Seizure freedom was achieved with modest or moderate daily doses (median CBZ 400mg, VPA 1000 mg, (LTG) 150 mg) of all three AEDs in the majority of patients achieving remission. Time to first seizure did not differ among these three drugs when given as first treatment. Adverse effects leading to withdrawal were more frequent with CBZ (16%) than with VPA (7%, P=0.03) or LTG (7%, P=0.018). In patients failing initial monotherapy, response to a combination of two AEDs (27%) was not different from that with alternative monotherapy (32%). The majority of patients with newly diagnosed epilepsy responding to treatment did so rapidly and completely with moderate doses of AEDs, with no differences in time to first seizure.     

Adverse effects of carbamazepine,phenytoin, valproate and lamotrigine monotherapy in epileptic adult Chinese patients

Objective

Antiepileptic drugs (AEDs) have been widely used in patients with epilepsy but the adverse effects in adult Chinese patients have not been investigated. This study evaluated the adverse effects of four commonly prescribed AED monotherapies with carbamazepine (CBZ), phenytoin (PHT), valproate (VPA), and lamotrigine (LTG) in adult Chinese patients with epilepsy.

Methods

The prospective open-label clinical trial was conducted at the Chongqing Epilepsy Center. The study enrolled 505 adults with newly diagnosed epilepsy, including generalized tonic–clonic (n = 110), partial and partial secondarily generalized (n = 395) seizures. Patients were evaluated by two clinicians at the Center and were prescribed one type of AED monotherapy with CBZ, PHT, VPA or LTG for a 24-month period. An adverse effect profile, as well as efficacy of monotherapy, was obtained through a face-to-face interview with the patient at each visit. A physical examination and routine laboratory tests were performed during a clinical screening.

Results

A total of 62.6% (316/505) patients successfully completed the AED monotherapy study: 64.3% of those receiving CBZ, 55.9%—PHT, 61.5%—VPA, and 66.2%—LTG. However, 34.7% of the patients discontinued the AED monotherapy because of unsatisfactory seizure control. Overall, 18% of patients experienced adverse effects: for CBZ (25/168; 14.9%), PHT (18/59; 30.5%), VPA (32/192; 16.7%) and LTG (16/86; 18.6%). The most common drug-related adverse events included gastrointestinal disturbances, loss of appetite and nausea, weight gain and fatigue/tiredness. Tremor and nystagmus occurred in some patients receiving PHT and VPA. Two CBZ, one PHT and four LTG patients (n = 7) discontinued the study due to rash.

Conclusion

Adult Chinese patients with epilepsy accepted and tolerated monotherapy with CBZ, PHT, VPA, and LTG. No fatal adverse events occurred. Unsatisfactory seizure control was a primary reason for withdrawal from the AED monotherapy study.     

Seizure freedom with different therapeutic regimens in intellectually disabled epileptic patients.

BACKGROUND: Epilepsy is a frequent condition in persons with intellectual disability and is more often difficult to treat than in the average population. Seizure freedom is the primary therapeutic goal which has important implications for the patient's quality of life. The aim of this study was to find out which antiepileptic therapy regimens (monotherapy or combination therapy) are effective in achieving this goal in intellectually disabled epilepsy patients. We were especially interested in the impact of the new antiepileptic drugs (AEDs) which were introduced during the past decade. METHOD: We investigated retrospectively the antiepileptic regimens on which the resident patients of a large epilepsy centre (as a rule with additional intellectual disabilities of different degrees) were seizure free in 2002. Information on antiepileptic medication and seizure frequency was taken out of the individual case documentation. It was also determined whether seizure free patients had already been seizure free in 1992. RESULTS: Two hundred and forty out of 675 patients (35,6%) with epilepsy were seizure free. The proportion of seizure freedom was 43,7% in patients with borderline intelligence, 39,2% in mild, 33,2% in moderate, 31,9% in severe, and 21,9% in profound intellectual disability. One hundred and twenty-two (50,8%) seizure free patients were on monotherapy; 53 of them were on CBZ (PB: 34, VPA: 25, PHT: 7, LTG: 3). Ninety-three patients (38,7%) were on duotherapies, CBZ/PB (27 patients), PB/PHT (17), and LTG/VPA (14) being the commonest. Of 18 (7,5%) triple therapies, LTG/PB/VPA (4 patients) was the commonest. Taken together, the five most frequent therapeutic regimens were CBZ monotherapy, PB monotherapy, CBZ/PB, VPA monotherapy and PB/PHT (a clear preponderance of classic AEDs). A distinction was made between "old seizure free" (seizure free already in 1992) and "new seizure free" (in 1992 still seizures) patients. In the 132 old seizure free patients the classic AEDs prevailed again, monotherapies with CBZ, PB and VPA being the most frequent regimens. In comparison, in the 78 new seizure free patients the novel combination LTG/VPA was the third most frequent, after the classic regimens CBZ/PB and CBZ; PB monotherapies were rare. CONCLUSION:In a majority of intellectually disabled patients with epilepsy (including those who became seizure free since 1992), complete seizure control has been achieved by monotherapy or duotherapy with classic AEDs. Of the new AEDs LTG in combination with VPA appears to be an important innovation.     

An international multicenter randomized double-blind controlled trial of lamotrigine and sustained-release carbamazepine in the treatment of newly diagnosed epilepsy in the elderly

PURPOSE: To assess the comparative effectiveness, efficacy, and tolerability of lamotrigine (LTG) and sustained-release carbamazepine (CBZ) in the treatment of newly diagnosed epilepsy in the elderly. METHODS: Patients aged 65 years or older, who had experienced at least two unprovoked partial and/or generalized tonic-clonic seizures, were randomized to receive LTG (n=93) or CBZ (n=92) according to a multicenter double-blind, parallel-group design. Trial duration was 40 weeks and included a 4-week dose escalation followed by a maintenance phase during which dosages could be adjusted according to response. Initial, maintenance and maximum dosages were 25 mg, 100 mg, and 500 mg per day for LTG, and 100 mg, 400 mg, and 2,000 mg per day for CBZ, respectively. The primary end point was retention in the trial. RESULTS: In the LTG group, 68 patients (73%) completed the 40-week study period compared with 61 (67%) in the CBZ group, a nonsignificant difference. Time to withdrawal from any cause did not differ between groups (p=0.34). The number of subjects who completed the 40-week period and were seizure free in the last 20 weeks was 48 (52%) in the LTG group and 52 (57%) in the CBZ group. Adverse events leading to withdrawal occurred in 13 (14%) subjects in the LTG group and 23 (25%) subjects in the CBZ group. CONCLUSION: LTG and CBZ showed comparable effectiveness, with a trend for higher seizure-free rates for CBZ and better tolerability for LTG. Differences in outcome compared with previous trials may be related to different dosing rates and use of a sustained-release formulation for CBZ.     

Lamotrigine versus valproic acid as first-line monotherapy in newly diagnosed typical absence seizures: an open-label, randomized, parallel-group study

PURPOSE: To compare the efficacy of lamotrigine (LTG) and valproic acid (VPA) in newly diagnosed children and adolescents with typical absence seizures. METHODS: A randomized, open-label parallel-group design was used. After undergoing an awake video-EEG recording, which included one to two trials of 3 min of hyperventilation and intermittent photic stimulation, eligible patients were randomized to receive LTG or VPA. LTG was initiated at a daily dose of 0.5 mg/kg for 2 weeks in two divided doses, followed by 1.0 mg/kg/day for an additional 2 weeks. Thereafter, doses were increased in 1-mg/kg/day increments every 5 days until seizures were controlled, intolerable adverse effects occurred, or a maximum dose of 12 mg/kg/day had been reached. VPA was equally uptitrated according to clinical response, starting at 10 mg/kg and increasing by 5 mg/kg/24 h every 3 days, if required, to a maximum of 30 mg/kg/day in three divided doses. Patients were seen in the clinic every month for < or = 12 months.The primary efficacy end point at each visit was seizure freedom, defined as lack of clinically observed seizures since the previous visit and lack of electroclinical seizures during ambulatory 24-h EEG testing and a video-EEG session with hyperventilation. RESULTS: Thirty-eight children (17 boys, 21 girls), aged from 3 to 13 years (mean, 7.5 years), all newly diagnosed with childhood or juvenile typical absence seizures, were enrolled. After 1 month of treatment, 10 (52.6%) of 19 children taking VPA and one (5.3%) of 19 taking LTG were seizure free (p = 0.004). By the 3-month follow-up, 12 (63.1%) children taking VPA and seven (36.8%) taking LTG were controlled (p = 0.19). After 12 months, 13 children taking VPA (dose range, 20-30 mg/kg/day; mean serum level, 76.8 mg/L; range, 51.4-91 mg/L) and 10 taking LTG (dose range, 2-11 mg/kg/day; mean serum level, 8.1 mg/L; range, 1.1-18 mg/L) were seizure free (p = 0.51). Side effects were mostly mild and transient and were recorded in two (10.6%) children treated with VPA and in six (31.8%) treated with LTG. CONCLUSIONS: Both VPA and LTG can be efficacious against absence seizures, although VPA shows a much faster onset of action, at least in part because of its shorter titration schedule.