Intravenous oxycodone, hydrocodone, and morphine in recreational opioid users: Abuse potential and relative potencies

William W. Stoops, Kevin W. Hatton, Michelle R. Lofwall, Paul A. Nuzzo, Sharon L. Walsh

Research output: Contribution to journalArticlepeer-review

62 Scopus citations


Rationale: Nonmedical use and abuse of prescription opioids is an increasing public health problem. Intravenous (IV) administration of opioid analgesics intended for oral use is not uncommon; yet, little is known about the relative abuse potential of these drugs when administered intravenously to recreational opioid abusers without physical dependence. Methods: This inpatient study employed a double-blind, randomized, within-subject, placebo-controlled design to examine the relative abuse potential of IV doses of oxycodone, hydrocodone, and morphine. Nine healthy adult participants reporting recreational opioid use and histories of IV opioid use completed 11 experimental sessions, including one active-dose practice session. IV doses were infused over 5 min and included three identical doses of each opioid (5, 10, and 20 mg/10 ml) and saline placebo. Physiological, subjective, and performance effects were collected before and for 6 h after drug administration. Results: All three opioids produced prototypical mu agonist effects (e.g., miosis; increased ratings of liking) that were generally dose-related. Pharmacodynamic effects were observed within 5 min of IV administration. Physiological effects were more prolonged than subjective effects for all three drugs. While the magnitude of effects was generally comparable across drugs and qualitatively similar, valid potency assays indicated the following potency relationship: oxycodone > morphine > hydrocodone. Conclusions: There were modest potency differences between oxycodone, hydrocodone, and morphine, but their overall profile of effects was similar, indicating significant abuse potential when administered intravenously.

Original languageEnglish
Pages (from-to)193-203
Number of pages11
Issue number2
StatePublished - Oct 2010

Bibliographical note

Funding Information:
Acknowledgements This research was supported by a grant from the National Institute on Drug Abuse (5R01DA016718-05) to Sharon L. Walsh and by the University of Kentucky CRDOC. The authors declare no conflicts of interest relevant to this project. The authors with to thank Lori Craig, Jessica DiCentes and Elizabeth Tammen for technical assistance and Stacy Miller, Todd McCoun, Pieter Steyn and Marie Thompson for medical assistance.


  • Abuse potential
  • Diversion
  • Hydrocodone
  • Morphine
  • Oxycodone
  • Prescription opioids

ASJC Scopus subject areas

  • Pharmacology


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