title: Relationship between rate of infusion and reinforcing strength of oxycodone in humans.
abstract: The rate of drug delivery to the central nervous system is believed to be an important predictor of the reinforcing strength of a drug. However, only a few studies have directly examined the relationship between drug-taking behavior and rate of drug administration. The purpose of the present experiment was to determine whether manipulating the infusion rate of a fixed dose of opioid alters its reinforcing effectiveness in humans. Twelve heroin-dependent participants (11 male, one female) completed the 2.5-week inpatient study. During test days, participants received $20 and a dose of drug (0 or 40 mg oxycodone administered intravenously over 2, 15, 30, 60, or 90 minutes) in random order during a morning sample session. Participants then worked for the sampled dose and/or money amount during an afternoon choice session by making finger presses on a computer mouse. Under these conditions, 40 mg oxycodone served as a reinforcer only when it was delivered over 2 and 15 minutes. Subjective ratings of drug liking, good effect, and high were similar to the self-administration results. Peak plasma levels of oxycodone generally occurred at the end of each infusion, eg, 2 minutes for the 2-minute infusion duration. Extended-release opioid medications are commonly prescribed for treating pain. The present results provide empirical support for the development of extended-release opioid medications that are difficult to convert into more rapid-acting forms. Specifically, these "abuse-deterrent formulations" could prevent patients from tampering with their medications to enhance their euphoric and reinforcing effects.
authors.affiliation: Department of Psychiatry, Columbia University, New York, New York, USA.
authors.forename: Sandra D
authors.initials: SD
authors.lastname: Comer
authors.forename: Judy B
authors.initials: JB
authors.lastname: Ashworth
authors.forename: Maria A
authors.initials: MA
authors.lastname: Sullivan
authors.forename: Suzanne K
authors.initials: SK
authors.lastname: Vosburg
authors.forename: Phillip A
authors.initials: PA
authors.lastname: Saccone
authors.forename: Richard W
authors.initials: RW
authors.lastname: Foltin
mesh_terms: D000328:Adult; D000701:Analgesics, Opioid / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008297:Male; D010098:Oxycodone / Q000008:administration & dosage* / Q000097:blood; D012054:Reinforcement, Psychology; D012646:Self Administration; D013647:Task Performance and Analysis
chemical_list: D000701:Analgesics, Opioid; D010098:Oxycodone