A Study of the Pharmacokinetics, Safety and Tolerability of Topiramate in Infants (Age 1-24 Months) With Refractory Partial-onset Seizures

Inclusion Criteria: Regular enteral feeding (solid food bottle- or cup-fed) with or without breastfeeding weigh >/=3.5 kilograms (kg) and <15.5 kg Length using an infant measuring table (heel to crown) must be = 49 cm clinical or electroencephalographic (EEG) evidence of POS (simple or complex) with or without secondary generalization of at least 1 month in duration in infants >6 months of age, or at least 2 weeks in duration in infants <6 months of age Multiple seizure types allowed as long as POS is present Taking 1 or 2 concurrent marketed antiepileptic drugs (AEDs) for >1 month for infants >6 months of age and for >2 weeks for infants <6 months of age the regimen of AEDs at entry must be considered inadequate in controlling seizures, after being optimized in the opinion of the investigator Have had a computerized tomography or magnetic resonance imaging scan to confirm the absence of a progressive lesion such as a tumor, with the exception of lesions of tuberous sclerosis and Sturge-Weber syndrome, which are allowed. Exclusion Criteria: Exclusively breast-fed and cannot take oral liquid medication Receives regular enteral feeding using gastrostomy, jejunostomy, or nasogastric tube have surgically implanted and functioning vagus nerve stimulator Have febrile seizures or seizures due to an acute medical illness Have infantile seizures as a result of a correctable medical condition such as metabolic disturbance, toxic exposure, neoplasm, or active infection History of nonepileptic seizures, either current or at any point in the past Any progressive neurologic disorder, including malignancy, brain tumor, active central nervous system infection, demyelinating disease, or degenerative or progressive central nervous system disease with the exception of tuberous sclerosis and Sturge Weber syndrome.