Oxytrex®: an oxycodone and ultra-low-dose naltrexone formulation
- 9 August 2007
- journal article
- review article
- Published by Informa Healthcare in Expert Opinion on Investigational Drugs
- Vol. 16 (8), 1277-1283
- https://doi.org/10.1517/13543784.16.8.1277
Abstract
Oxytrex® (Pain Therapeutics, Inc.) is an oral opioid that combines a therapeutic amount of oxycodone with an ultra-low dose of the antagonist naltrexone. Animal data indicate that this combination minimizes the development of physical dependence and analgesic tolerance while prolonging analgesia. Oxytrex is in late-stage clinical development by Pain Therapeutics for the treatment of moderate-to-severe chronic pain. To evaluate the safety and efficacy of the oxycodone/naltrexone combination, three clinical studies have been conducted, one in healthy volunteers and the other two in patients with chronic pain. The putative mechanism of ultra-low-dose naltrexone is to prevent an alteration in G-protein coupling by opioid receptors that is associated with opioid tolerance and dependence. Opioid agonists are initially inhibitory but become excitatory through constant opioid receptor activity. The agonist/antagonist combination of Oxytrex may reduce the conversion from an inhibitory to an excitatory receptor, thereby decreasing the development of tolerance and physical dependence.Keywords
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