Likelihood of requiring treatment during the study period with drugs not permitted by the clinical study protocol. Excluded meds: Treatment with CYP 3A4 inhibitors (macrolide antibiotics, itraconazole, indinivir, ritinivir, ketoconazol, verapamil, propoxyphene, fluoxetine) or inducers (rifampicin, carbamazepine, phenobarbitol, phenytoin). Treatment with sedative hypnotics or drugs with 5-HT2A or 5-HT3 activity (clozapine, risperidone, olanzapine, quetiapine, trazodone, nefazodone, mianserin, mirtazapine, cyproheptadine, ondansetron, granisetron, dolasetron). Treatment with drugs that are known to significantly prolong the QT interval of the ECG.