Document Detail

Discriminative stimulus effects of tramadol in humans.
MedLine Citation:
PMID:  21467190     Owner:  NLM     Status:  MEDLINE    
Tramadol is an unscheduled atypical analgesic that acts as an agonist at μ-opioid receptors and inhibits monoamine reuptake. Tramadol can suppress opioid withdrawal, and chronic administration can produce opioid physical dependence; however, diversion and abuse of tramadol is low. The present study further characterized tramadol in a three-choice discrimination procedure. Nondependent volunteers with active stimulant and opioid use (n = 8) participated in this residential laboratory study. Subjects were trained to discriminate between placebo, hydromorphone (8 mg), and methylphenidate (60 mg), and tests of acquisition confirmed that all volunteers could discriminate between the training drugs. The following drug conditions were then tested during discrimination test sessions: placebo, hydromorphone (4 and 8 mg), methylphenidate (30 and 60 mg), and tramadol (50, 100, 200, and 400 mg). In addition to discrimination measures, which included discrete choice, point distribution, and operant responding, subjective and physiological effects were measured for each test condition. Both doses of hydromorphone and methylphenidate were identified as hydromorphone- and methylphenidate-like, respectively. Lower doses of tramadol were generally identified as placebo, with higher doses (200 and 400 mg) identified as hydromorphone, or opioid-like. The highest dose of tramadol increased ratings on the stimulant scale, but was not significantly identified as methylphenidate-like. Tramadol did not significantly increase subjective ratings associated with reinforcement. Taken together, these results extend previous work with tramadol as a potential medication for the treatment of opioid dependence and withdrawal, showing acute doses of tramadol exhibit a profile of effects similar to opioid agonists and may have abuse liability in certain populations.
Angela N Duke; George E Bigelow; Ryan K Lanier; Eric C Strain
Publication Detail:
Type:  Comparative Study; Journal Article; Randomized Controlled Trial; Research Support, N.I.H., Extramural     Date:  2011-04-05
Journal Detail:
Title:  The Journal of pharmacology and experimental therapeutics     Volume:  338     ISSN:  1521-0103     ISO Abbreviation:  J. Pharmacol. Exp. Ther.     Publication Date:  2011 Jul 
Date Detail:
Created Date:  2011-06-23     Completed Date:  2011-08-30     Revised Date:  2014-09-13    
Medline Journal Info:
Nlm Unique ID:  0376362     Medline TA:  J Pharmacol Exp Ther     Country:  United States    
Other Details:
Languages:  eng     Pagination:  255-62     Citation Subset:  IM    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Conditioning, Operant / drug effects*,  physiology
Discrimination Learning / drug effects*,  physiology
Double-Blind Method
Reinforcement Schedule*
Tramadol / pharmacology*
Grant Support
K24 DA023186/DA/NIDA NIH HHS; K24-DA23186/DA/NIDA NIH HHS; R01 DA018125/DA/NIDA NIH HHS; R01 DA018125-04/DA/NIDA NIH HHS; R01 DA018125-05/DA/NIDA NIH HHS; R01 DA018125-06/DA/NIDA NIH HHS; R01-DA18125/DA/NIDA NIH HHS; T32-DA07209/DA/NIDA NIH HHS
Reg. No./Substance:

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  The effect of exercise therapy on fatigue in multiple sclerosis.
Next Document:  Inhibition of Rab1 GTPase and endoplasmic reticulum-to-Golgi trafficking underlies statin's toxicity...