Safety Study of Riluzole to Treat Post-traumatic Stress Disorder (PTSD)

Riluzole is a glutamatergic modulator that inhibits glutamate release and enhances AMPA trafficking and clearance of excessive synaptic glutamate resulting in neuroprotective properties. Riluzole is FDA-approved for the treatment of amyotrophic lateral sclerosis (ALS) and has been found to have antidepressant and anxiolytic properties in animals and in humans (Zarate et al., 2004). Posttraumatic stress disorder (PTSD) is a chronic and seriously debilitating anxiety disorder that develops following exposure to severe trauma, such as combat exposure. Structural magnetic resonance imaging has been used to measure the volume of crucial structures implicated in the pathophysiology of PTSD, with several morphometric studies confirming smaller hippocampal volume in PTSD patients. Current pharmacological treatment for PTSD, and particularly combat-related PTSD, is suboptimal. Drugs that alter neuronal survival pathways through reduction of glutamate activity may play a role in reversing the loss of neuronal integrity and possible focal atrophy in regions of the brain implicated in the pathophysiology of PTSD, potentially improving the symptoms of PTSD, as well as TBI. This study will evaluate the efficacy of acute riluzole treatment in active duty and Operation Iraqi Freedom (OIF), Operation Enduring Freedom (OEF), and Operation New Dawn (OND) veterans with PTSD, with or without mild TBI (mTBI), who are sub-optimally responsive to other medication treatments. A total of 158 active duty and OIF, OEF and OND veterans, aged 18 to 65 will be enrolled from WRNMMC and the Syracuse VA Medical Center to participate in this 8-week randomized, double- blind, placebo-controlled, parallel study. Patients who are suboptimal responders to their current psychotropic drugs will continue these at stable dosage for at least 2 weeks prior to randomization during the screening period. We hypothesize that those subjects with PTSD, with or without mTBI, who are only partially responsive to initial therapy and are subsequently randomized to augmentation therapy with Riluzole (100-200mg/day) will have a superior response rate compared to those subjects randomized to placebo.