Topiramate titration to response: analysis of individualized therapy study (TRAITS).

OBJECTIVE

To evaluate the relationship between baseline seizure frequency and stabilized topiramate dosage and the effect of individualized treatment on tolerability in adults with partial-onset seizures receiving other antiepileptic drugs (AEDs).

METHODS

In this 20-week, open-label trial, dosages of medications were adjusted according to clinical response. Dosage and seizure response data were analyzed for 2 groups defined by baseline seizure frequency: <4 and >/=4 seizures per month.

RESULTS

In the outcome evaluable population (n = 471), the mean +/- SEM stable topiramate dosage was 303 +/- 139 mg/d when baseline seizure frequency was <4 seizures/month and 341 +/- 153 mg/d when baseline seizure frequency was >/=4 seizures/month (p = 0.005). The most common adverse events were somnolence (8.5%), fatigue (7.3%), nausea (5.3%), and dizziness (5.0%). Cognitive complaints were reported by <3% of patients. When concomitant AED dosages were reduced, 14% of patients discontinued topiramate due to adverse events compared with 23% if the concomitant AED dosage was unchanged or increased.

CONCLUSIONS

When clinicians individualize topiramate dosage according to clinical response, the stabilized topiramate dosage as add-on therapy is influenced by baseline seizure frequency. Topiramate tolerability is improved when dosages of concomitant AEDs are reduced.