- Concomitant medications must be stable for >4 weeks prior to enrollment. The following concomitant medications are permitted: anticonvulsants which do not have liver inducing effects; beta-blockers; medications for the treatment of gastroesophageal reflux disease (GERD); medications for the treatment of chronic respiratory conditions such as asthma; medications for the treatment of anxiety, of depression and of psychosis, hormonal contraceptives. Melatonin for difficulties with sleep onset.