- Current or past history of seizure disorder or brain injury (traumatic or disease-related); or any condition which, in the opinion of the investigator, predisposes to seizure - Women having a positive serum HCG pregnancy test at screening, a positive urine pregnancy test before admission to the Unit during the in-house periods, who are not willing to use acceptable methods of contraception or who are lactating or planning to become pregnant within the three months following the screening visit.