Although all prescription opioids can be abused, oxycodone may be more potent in its ability to promote changes in the brain relevant to addiction.
Opioids such as morphine and oxycodone are prescribed for pain management but are also drugs of abuse. While the mechanisms underlying drug addiction are not fully understood, research published in the European Journal of Neuroscience
(online, 11 September 2014) reveals “dramatic differences” between oxycodone and morphine in their impact on dopamine transmission in the brain.
Rats given morphine showed a brief, transient increase in dopamine and GABA levels, which rapidly returned to baseline. By contrast, oxycodone led to a “robust and stable” rise in dopamine and markedly increased dopamine release events.
“Investigating these differences may be essential for understanding how these two drugs of abuse could differentially usurp motivational circuitry and powerfully influence behaviour,” say Brandon Aragona, from the University of Michigan, and co-authors.
 Vander Weele CM, Porter-Stransky KA, Mabrouk OS et al. Rapid dopamine transmission within the nucleus accumbens: Dramatic difference between morphine and oxycodone delivery. European Journal of Neuroscience 2014;40:3041–3054. doi:10.1111/ejn.12709 (accessed 11 September 2014).