The Effects of Dextromethorphan on Driving Performance and the Standardized Field Sobriety Test.
Journal of Forensic Sciences September 1, 2015 Paul J. Perry, Kristian Fredriksen, Stephanie Chew et al.
A single 120 mg dose of dextromethorphan, the maximum recommended daily dose, does not impair driving performance or increase failures on a standardized field sobriety test compared to a 400 mg dose of guaifenesin. Forty healthy adults completed a crossover trial using a driving simulator and field sobriety tests one hour after taking the drug. Doses higher than 120 mg are needed to affect driving behavior. Dextromethorphan is commonly abused by adolescents for its dissociative effects, but at the maximum therapeutic dose it does not appear to compromise driving ability.