Abstract
Opioid and nonopioid components independently contribute to the mechanism of action of tramadol, an 'atypical' opioid analgesic.
R B Raffa, E Friderichs, W Reimann, R P Shank, E E Codd and J L Vaught
Journal of Pharmacology and Experimental Therapeutics January 1992, 260 (1) 275-285;