Abstracts

RATIONALE: Tiagabine (TGB) has been shown to be effective in the treatment of partial epilepsy in adults. Given its predictable linear pharmacokinetics, well known mechanism of action on the GABA system, and absence of visual field loss, TGB has a potential role in the management of intractable epilepsy in childhood. However, clinical data in children is limited. METHODS:_We retrospectively reviewed the records of 43 patients (age <20 years) treated with TGB and followed at Children's Hospital (Boston) from 1/1/99 to 12/31/99, with respect to efficacy (seizure reduction >50%), duration of treatment, and the presence of side effects. RESULTS:_TGB was administered to patients with various epilepsy syndromes including partial epilepsies, Lennox-Gastaut syndrome, infantile spasms, and other generalized epilepsies. Average age was 10.5 years. 1-17 other AEDs had been tried prior to TGB therapy. Efficacy was seen in 11/24 patients with partial seizures with or without generalization; 4/17 with tonic/atonic attacks; 1/4 with infantile spasms; 0/6 with generalized tonic-clonic seizures; and 0/5 with myoclonic seizures. TGB accounted for seizure exacerbation in 2/24 patients with partial seizures and 6/22 with generalized seizure types. One child with partial epilepsy had a new onset of non-convulsive status epilepticus. The most common side effects included behavioral exacerbation (n=6), new onset of myoclonic jerks (n=4), tremor (n=6), intermittent weakness and loss of tone (n=4), and other non-specific side effects, e.g. lethargy and irritability (n=10). Median duration of treatment at the end of 1999 with or without discontinuation was 10 months. TGB was discontinued in 18 patients (42%) due to lack of efficacy (13/18), increase in seizure frequency (6/18), or other adverse effects (7/18), occurring in combination or isolation. CONCLUSIONS:_The usefulness of TGB in the treatment of childhood intractable epilepsy appeared to be limited to partial seizures. We found little or no effectiveness on generalized seizures, which were exacerbated in one-quarter of the patients. Otherwise, there were no serious adverse events.