Vigabatrin vs. carbamazepine monotherapy in newly diagnosed focal epilepsy: a randomized response conditional cross-over study. A comparative study of vigabatrin vs. carbamazepine in monotherapy of newly diagnosed partial seizures in children. A randomised open multicentre comparative trial of lamotrigine and carbamazepine as monotherapy in patients with newly diagnosed or recurrent epilepsy. Multicentre, double-blind, randomised comparison between lamotrigine and carbamazepine in elderly patients with newly diagnosed epilepsy. The UK Lamotrigine Elderly Study Group. Comparison of antiepileptic drugs on cognitive function in newly diagnosed epileptic children: a psychometric and neurophysiological study.
The clinical efficacy and safety of vigabatrin (VGB) as add-on therapy for pharmaco-resistant focal epilepsies is well established. However, for an objective evaluation, the effects of the drug in the monotherapy of newly diagnosed subjects should be determined. With this aim, VGB was compared, in a randomized, response conditional cross-over study, with carbamazepine (CBZ), the most widely prescribed drug in focal epilepsies. Fifty-one patients with complex partial (CP) seizures were randomly assigned to either the VGB or the CBZ group and evaluated after an initial 4 month period. The cross-over to the alternative drug was carried out, for an analogous period, only in cases with persisting seizures or in the presence of intolerable side effects. Patients who did not respond to either drug were subsequently treated with a combination of VGB and CBZ. No significant difference was revealed in the efficacies of VGB and CBZ; a complete control of seizures was obtained in 17/37 patients (45.9%) treated with VGB and in 20/39 patients (51.3%) treated with CBZ. The side effects were somewhat more frequent (41%) and severe with CBZ than with VGB (21.6%). The power to detect a 20% difference between the two drugs was 75%. The combination of the two drugs suppressed the seizures in 5 out of 14 resistant cases. The preliminary results in this small number of patients are encouraging and suggest that VGB may be considered as a first-line drug for epilepsy with CP seizures and as a valid alternative when other monotherapies are ineffective or poorly tolerated. Carbamazepine (CBZ) is a drug of choice for the treatment of simple or complex partial seizures and secondary generalized seizures in adults and children. Vigabatrin (VGB) is a relatively new second line antiepileptic drug and was first registered for use in Poland more than ten years ago. Few reports have been published on the comparison of efficacy of VGB in children with epilepsy. The objective of this study is to evaluate the safety, efficacy and EEG effects of initial VGB monotherapy compared with initial CBZ monotherapy in children with newly diagnosed epilepsy. We present results of a prospective, outpatient and open study carried out in the University Hospital Center in Białystok. Twenty-six children with partial epilepsy treated with VGB and 28 patients treated with CBZ were studied. The evaluation of the efficacy of the two drugs did not reveal any significant differences. Very good (reduction > 75%) seizure control was achieved in 22 out of 26 patients (84.6%) in the VGB group. One patient had a 50-75% decrease of seizures (good effect), similarly one child had a 25-50% reduction of seizures (mild effect). In two patients, we observed increased seizures (myoclonic jerks). Very good seizure control was achieved in 17 out of 28 patients (60.7%) in the CBZ group. Good seizure control was achieved in 5 out of 28 patients (17.8%) and mild control was seen in two children. No improvement was observed in 4 (14%) of the patients. The EEG background activity was improved in VGB-treated patients. No effect on the EEG background activity was observed in CBZ-treated children. VGB seems to be a safe and effective antiepileptic drug as primary monotherapy for epilepsy in children with similar proportion of side effects as CBZ. The efficacy and safety of lamotrigine and carbamazepine as monotherapy in patients with untreated, newly diagnosed or recurrent partial and/or generalised tonic-clonic seizures, were compared in a randomised, open, multicentre study. Patients received 24 weeks' treatment with oral lamotrigine 100 mg (LTG 100, n = 115) or 200 mg (LTG 200, n = 111) or carbamazepine 600 mg (CBZ 600, n = 117). Efficacy measurements were comparable between the three treatment groups, although the higher lamotrigine dose was possibly most effective, with 60.4% completing seizure free compared with 51.3% (LTG 100) and 54.7% (CBZ 600). Both dosage regimens of lamotrigine were well tolerated. More patients on CBZ 600 reported adverse experiences, 66% versus 53% (LTG 100) and 58% (LTG 200), and of these a greater proportion were attributed to CBZ 600 treatment, 53% versus 23% (LTG 100) and 28% (LTG 200). Similarly, a greater proportion of the CBZ 600 group required a change in dose, 47% versus 20% (LTG 100) and 17% (LTG 200) or withdrew completely due to adverse experiences, 10.3% versus 4.3% (LTG 100) and 4.5% (LTG 200). The most common adverse experience leading to withdrawal was rash, with approximately double the proportion of reports occurring in patients on CBZ 600 (5.1%) compared with lamotrigine (1.7% on LTG 100 and 2.7% on LTG 200). Overall lamotrigine appeared equally effective but better tolerated compared with carbamazepine. In a multicentre, double-blind trial 150 elderly patients (mean age 77 years) with newly diagnosed epilepsy were randomised in a 2:1 ratio to treatment with lamotrigine (LTG) or carbamazepine (CBZ). Following a short titration period, the dosage was individualised for each patient while maintaining the blind over the next 24 weeks. The main difference between the groups was the rate of drop-out due to adverse events (LTG 18% versus CBZ 42%). This was in part a consequence of the lower rash rate with LTG (LTG 3%, CBZ 19%; 95% CI 7-25%). LTG-treated patients also complained less frequently of somnolence (LTG 12%, CBZ 29%; 95% CI 4-30%). Although there was no difference between the drugs in time to first seizure, a greater percentage of LTG-treated patients remained seizure-free during the last 16 weeks of treatment (LTG 39%, CBZ 21%; P = 0.027). Overall, more patients continued on treatment with LTG than CBZ (LTG 71%, CBZ 42%; P < 0.001) for the duration of the study. The hazard ratio for withdrawal was 2.4 (95% CI 1.4-4.0) indicating that a patient treated with CBZ was more than twice as likely to come off medication than one taking LTG. In conclusion, LTG can be regarded as an acceptable choice as initial treatment for elderly patients with newly diagnosed epilepsy. Using a randomized parallel group study design, we compared the cognit ive effects of carbamazepine (CBZ), phenobarbital (PB), and valproate (VPA) in children with epilepsy. Seventy-three children with newly diagnosed epilepsy were tested with the Wechsler Intelligence Scale for Children-Revised (WISC-R), Bender-Gestalt test, and auditory event-related potentials (P 300) before and 6 and 12 months after antiepileptic drug (AED) treatment. There were no significant differences in WISC-R IQs and Bender-Gestalt scores for children in any group at any of the three sessions. P 300 latencies were increased in the children receiving PB but not in children receiving CBZ and VPA. P 300 amplitudes were significantly reduced in treated children in all three groups, but amplitudes were not significantly different among the three groups. These findings suggest that PB may affect cognitive function of epileptic children and that the P 300 may be a sensitive additional procedure that can be used to assess the cognitive effect of AEDs.
There is currently insufficient data to address the risk-benefit balance of using VGB versus CBZ monotherapy for epilepsy. Considering the high prevalence of visual field defects, reported in an existing systematic review of observational studies (Maguire 2010), the prescribing of VGB monotherapy for epilepsy should be used with caution and not considered as a first-line choice. If necessary, a frequent assessment of visual field is needed. Future research should focus on investigating the reasons for visual field defects and exploring the potential prevention strategies. Moreover, future monotherapy studies of epilepsy should report results according to the recommendation of International League Against Epilepsy (ILAE) Commission, and methodological quality should be improved.