Prevention/Reduction of ASRs and PTSD to Sustain Civilian Performance With Sublingual Cyclobenzaprine HCl (TNX-102 SL)

This study tests whether sublingual cyclobenzaprine (a muscle relaxant placed under the tongue) can prevent or reduce acute stress reactions and PTSD symptoms in people who have just been in a car accident. It is given in the emergency room shortly after the accident. **You may be eligible if...** - You are 18–55 years old and came to the emergency room within 24 hours of a car accident - You are expected to be discharged home (not admitted to the hospital) - You have a moderate-to-high risk score for developing PTSD after the accident - You have significant pain (4 or higher on a 0–10 scale) - You have a smartphone and personal email address - You are able to use effective contraception if you could become pregnant **You may NOT be eligible if...** - You have a major injury such as a broken bone - You are pregnant or breastfeeding - You are a prisoner - You take daily opioid medications - You have active psychosis or suicidal thoughts - You have a heart condition (arrhythmia, heart failure, recent heart attack) - You have a known allergy to cyclobenzaprine Talk to your doctor to see if this trial is right for you.