Effects of the benzodiazepine antagonist flumazenil in PTSD

OBJECTIVE: Evidence from preclinical and clinical studies suggests a role for alterations in the benzodiazepine/GABAA receptor complex in stress and anxiety. Flumazenil is a relatively pure benzodiazepine/GABAA antagonist with limited intrinsic activity. In panic disorder patients, but not healthy controls, flumazenil has been demonstrated to provoke panic attacks. METHOD: Vietnam combat veterans with PTSD (n = 14) received 90-second intravenous infusions of flumazenil 2 mg or placebo in a double-blind, crossover study design. PTSD symptomology was assessed using the PTSD Symptom Scale, and anxiety symptoms were measured with visual analogue rating scales. RESULTS: There was no significant difference in PTSD and anxiety symptoms between administration of flumazenil and placebo. CONCLUSION: Flumazenil administration does not produce an increase in anxiety and PTSD symptoms in patients with PTSD. This suggests that PTSD and panic disorder are dissimilar in terms of benzodiazepine/GABAA system function.