20
Participants
Start Date
November 30, 2007
Primary Completion Date
April 30, 2010
Study Completion Date
August 31, 2011
tramadol
oral dose, once per day
placebo
oral dose, once per day
Hydromorphone
oral dose, once per day
Methylphenidate
oral dose, once per day
Behavioral Pharmacology Research Unit, Baltimore
National Institute on Drug Abuse (NIDA)
NIH