Felbamate as an add-on therapy for refractory epilepsy.
BACKGROUND
Epilepsy is a chronic and disabling neurologic disorder, affecting approximately one per cent of the population. Up to 30% of people with epilepsy have seizures that are resistant to currently available drugs. Felbamate is one of the second generation antiepileptic drugs and its effects as an add-on therapy to standard drugs are assessed in this review.


OBJECTIVE
To evaluate the efficacy and tolerability of felbamate versus placebo when used as an add-on treatment for people with refractory partial-onset epilepsy.


METHODS
We searched the Cochrane Epilepsy Group Specialized Register (6 December 2010), the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, 6 December 2010), and PubMed (6 December 2010). There were no language restrictions. We reviewed the reference lists of retrieved studies to search for additional reports of relevant studies. We also contacted the manufacturers of felbamate and experts in the field for information about any unpublished or ongoing studies.


METHODS
Randomized placebo-controlled add-on studies of people of any age with refractory partial-onset seizures. The studies could be double-blind, single-blind or unblinded and could be of parallel or crossover design.


METHODS
Two review authors independently selected studies for inclusion and extracted information. Disagreements were resolved by discussion. If disagreements persisted, the third review author arbitrated. The following outcomes were assessed: 50% or greater reduction in seizure frequency; absolute or percentage reduction in seizure frequency; treatment withdrawal; adverse effects; quality of life.


RESULTS
Three randomized controlled trials were included. The first was a parallel design, the second was a two-period crossover design, and the third was a three-period crossover design. Due to significant methodological heterogeneity, clinical heterogeneity and differences in outcome measures, it was not possible to perform a meta-analysis of the results. None of the three studies reported 50% or greater reduction in seizure frequency. Only one study reported absolute and percentage reduction in seizure frequency compared to placebo, P values were 0.046 and 0.018, respectively. Adverse effects rates were higher during the felbamate period than the placebo period, particularly headache, nausea and dizziness.


CONCLUSIONS
In view of the methodological deficiencies, limited number of individual studies and differences in outcome measure, we have found no reliable evidence to support the use of felbamate as an add-on therapy in patients with refractory partial-onset epilepsy. A large scale, randomized controlled trial conducted over a greater period of time is required to inform clinical practice.
Nantong University Library, Evidence-based Medicine Center, Medical School of Nantong University, Nantong, China.
Li Li
LL
Shi
Jiancheng
J
Dong
Hengjian
H
Ni
Jinsong
J
Geng
Taixiang
T
Wu
D000927:Anticonvulsants / Q000009:adverse effects / Q000627:therapeutic use*; D004828:Epilepsies, Partial / Q000188:drug therapy*; D000078328:Felbamate; D006801:Humans; D048448:Phenylcarbamates / Q000009:adverse effects / Q000627:therapeutic use*; D011409:Propylene Glycols / Q000009:adverse effects / Q000627:therapeutic use*; D016032:Randomized Controlled Trials as Topic
D000927:Anticonvulsants; D048448:Phenylcarbamates; D011409:Propylene Glycols; D000078328:Felbamate