Concomitant medications known to lower the seizure threshold discontinued or substituted at least 4 weeks (30 days) prior to Step 1 registration Have used or plan to use from 30 days prior to enrollment through the end of the study medication known to lower the seizure threshold or prolong the QT interval Medications known to lower the seizure threshold must be discontinued or substituted prior to study treatment initiation Medications known to lower the seizure threshold (see Appendix 1) must be discontinued or substituted at least 4 weeks prior to study entry. Use of any prohibited concomitant medications within 14 days prior to treatment start, or use of prohibited concomitant medications within the outlined windows\r\n* Note: Medications known to lower the seizure threshold must be discontinued or substituted at least 4 weeks prior to treatment start Use of medications known to lower the seizure threshold within 4 weeks prior to study entry Medications known to lower the seizure threshold must be discontinued or substituted at least 4 weeks prior to study entry Medications known to lower the seizure threshold (see list under prohibited meds) must be discontinued or substituted at least 4 weeks prior to study entry Medications known to lower the seizure threshold must be discontinued or substituted at least 4 weeks prior to study entry Medications known to lower the seizure threshold must be discontinued or substituted at least 4 weeks prior to study entry Medications known to lower the seizure threshold must be discontinued or substituted at least 4 weeks prior to study entry Medications known to lower the seizure threshold (see list under prohibited meds) must be discontinued prior to study entry Medications known to lower the seizure threshold must be discontinued or substituted at least 4 weeks prior to study entry Concurrent therapy with any of the following (all must have been discontinued or substituted for at least 1 week prior to randomization, except for medications known to lower seizure threshold which must be discontinued or substituted at least 4 weeks prior to randomization) Medications known to lower the seizure threshold Prior treatment with medications known to lower the seizure threshold within 4 weeks of registration Concomitant medications that lower seizure threshold History of seizures or medications known to lower seizure threshold current use of medication that may lower seizure threshold Medications which lowers seizure threshold Concurrent therapy with medications known to have seizure potential (those must have been discontinued or substituted for at least 28 days prior to starting the trial) No history of seizures or medical conditions which may lower seizure threshold Use of a medication known to lower the seizure threshold within 28 days of first dose of study drug Medications known to lower the seizure threshold must be discontinued or substituted prior to study treatment