In vivo microdialysis and conditioned place preference studies in rats are consistent with abuse potential of tramadol
Sprague JE, Leifheit M, Selken J,
Milks MM, Kinder DH, Nichols DE.
The Department of Pharmaceutical & Biomedical Sciences,
The Raabe College of Pharmacy,
Ohio Northern University, Ada, Ohio 45810.
Synapse 2002 Feb;43(2):118-21


The abuse potential of tramadol was investigated using both in vivo microdialysis measures of dopamine (DA) release within the nucleus accumbens (NAc) shell and the conditioned place preference (CPP) paradigm in rats. Tramadol (75 mg/kg, i.p.) induced a statistically significant increase (starting 80 min posttreatment) in DA release within the NAc shell, which was maintained for at least 120 min posttreatment. Tramadol (18.75, 37.5, and 75 mg/kg i.p.) produced a statistically significant CPP, with the effects of the two highest doses comparable to those induced by morphine (5 mg/kg, s.c.). The release of DA within the NAc shell may be responsible for the rewarding properties of tramadol and, together with the CPP results, provide evidence that tramadol may possess greater abuse potential than originally believed.
Ultram abuse?
Tramadol (Ultram)
Tramadol: seizures
Tramadol: metabolites
Tramadol: mechanisms
Tramadol and analgesia
Tramadol: pharmacology
Tramadol and acute pain
Tramadol abuse in Gaza?
Tramadol and osteoarthritis
Tramadol as an antidepressant
Discriminative stimulus effects
Tramadol versus buprenorphine
Tramadol : morning or evening?

and further reading

Future Opioids
BLTC Research
Utopian Surgery?
The Abolitionist Project
The Hedonistic Imperative
The Reproductive Revolution
Critique of Huxley's Brave New World

The Good Drug Guide
The Good Drug Guide

The Responsible Parent's Guide
To Healthy Mood Boosters For All The Family