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.     

Metabolic and hormonal disturbances in women with epilepsy on antiepileptic drug monotherapy

PURPOSE: Women with epilepsy (WWE) tend to have hormonal and metabolic abnormalities, raising concerns about an increased risk of cardiovascular disorders. This study was performed to determine whether epilepsy itself and/or antiepileptic drug (AED) medication cause metabolic abnormalities. METHODS: WWE in premenopausal state aged 18 to 45 years old, currently on AED monotherapy for more than six months, were recruited for this study. The subjects checked their oral temperature each morning, and tested serum levels for lipid profiles, insulin, glucose, and leptin. A HOMA-index was used as a marker for insulin resistance. RESULTS: Of the 54 total patients, 18 women were diagnosed with primary generalized epilepsy (PGE) and the other 36 were diagnosed with localization-related epilepsy (LRE). Among the subjects, 19 women were on carbamazepine (CBZ), 12 on valproate (VPA), 12 on lamotrigine (LTG), and 11 on topiramate (TPM). Body mass index increased and HDL-cholesterol decreased in patients on VPA monotherapy compared with CBZ, LTG, or TPM (p=0.046 and 0.002). Metabolic syndrome was more frequently associated with VPA-treated patients (41.7%) than CBZ (5.3%), LTG (0%), or TPM group (0%) (p=0.005). There were no differences in hormonal and metabolic indices between PGE and LRE groups. CONCLUSIONS: WWE on VPA monotherapy are more obese and more frequently suffer from metabolic syndrome. LTG or TPM may be safer when prescribed to the patients with high risk of cardiovascular disease.     

Long-term effectiveness of ethosuximide, valproic acid, and lamotrigine in childhood absence epilepsy

Purpose: We performed this study to evaluate the long-term efficacy and tolerability of ethosuximide (ESX), valproic acid (VPA), and lamotrigine (LTG) as initial monotherapies for patients with newly diagnosed childhood absence epilepsy. Methods: We retrospectively reviewed the medical records of 128 patients (45 boys and 83 girls) diagnosed with childhood absence epilepsy at the Seoul National University Hospital. The diagnosis was based on the criteria proposed by Panayiotopoulos in 2005. We measured the seizure-free rate and the retention rate observed during 2 years of treatment. Follow-up electroencephalography (EEG), any reported adverse events, and reasons for antiepileptic drug (AED) discontinuation were reviewed. Results: The seizure-free rate of ESX (84%) was significantly higher than that of VPA (62%) and LTG (53%) at 3 months. The seizure-free rate of ESX (90%) was significantly higher than that of LTG (63%) at 6 months. After 9 months, there was no significant difference in seizure-free rate among the three groups. There were no significant differences among the three groups in terms of normalization of EEG at 12 months (ESX, 77%; VPA, 83%; and LTG, 64%), retention rate throughout the whole treatment period, and adverse-event rates (ESX, 25%; VPA, 29%; and LTG, 14%). Conclusion: This study suggests that ESX, VPA, and LTG are equally effective in the long-term treatment of newly diagnosed CAE patients. However, the onset of efficacy was faster for ESX compared with VPA or LTG. Efficacy, tolerability, and adverse event profiles should be carefully considered when selecting AEDs to treat individual patients with CAE.     

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.     

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.     

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.     

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.     

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.     

Topiramate,carbamazepine and valproate monotherapy: double-blind comparison in newly diagnosed epilepsy

OBJECTIVES: To compare topiramate (TPM) with investigator's choice of carbamazepine (CBZ) or valproate (VPA) for initial treatment in patients with newly diagnosed epilepsy. MATERIAL AND METHODS: In patients with epilepsy diagnosed within previous 3 months, investigators selected CBZ (600 mg/day) or VPA (1250 mg/day) as preferred therapy based on the patient's clinical presentation. Based on investigators' treatment choice, patients (n=613) were assigned to the CBZ or VPA treatment branch. Within each branch, patients were randomized to double-blind treatment with the traditional antiepileptic drugs (CBZ or VPA), TPM 100 mg/day, or TPM 200 mg/day. Patients continued double-blind treatment until exiting the study or until 6 months after last patient randomized. RESULTS: No statistically significant differences between fixed doses of TPM and CBZ or VPA were observed in efficacy measures: time to exit, time to first seizure, and the proportion of patients seizure-free during the last 6 months of treatment. TPM 100 mg/day was associated with the fewest discontinuations due to adverse events. CONCLUSION: In patients with newly diagnosed epilepsy, an initial target dose of TPM 100 mg/day is at least as effective as therapeutic doses of CBZ and VPA.     

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.