The oxycodone component is an opioid and is responsible for the pain-relieving effects. Naloxone, an opioid antagonist, opposes the effects of opioids but is poorly absorbed into the blood stream when administered orally; therefore, most of the dose remains in the gastrointestinal tract. This local presence reduces opioid-induced constipation by preventing oxycodone from binding to gut opioid receptors, without diminishing overall analgesic efficacy compared to oxycodone alone. A 2008 study demonstrated a significant reduction in constipation.[6] Oxycodone/naloxone was released in 2014 in the United States,[5] in 2006 in Germany, and has been available in some other European countries since 2009. In the United Kingdom, the 10 mg oxycodone / 5 mg naloxone and 20 mg / 10 mg strengths were approved in December 2008, and the 40 mg / 20 mg and 5 mg / 10 mg strengths received approval in July 2019.[7]
Preliminary evidence suggests that oxycodone/naloxone may be an effective treatment for severe, refractory restless legs syndrome if first-line therapies have not been effective.[8][9][10]
^"Public Summary". www.ebs.tga.gov.au. Australian Government, Department of Health and Aged Care. Retrieved 20 May 2024.
^"Oxonal (AU Pharma Pty Ltd)". Therapeutic Goods Administration (TGA). 28 September 2022. Archived from the original on 18 March 2023. Retrieved 9 April 2023.
^Trenkwalder C, Beneš H, Grote L, García-Borreguero D, Högl B, Hopp M, et al. (December 2013). "Prolonged release oxycodone-naloxone for treatment of severe restless legs syndrome after failure of previous treatment: a double-blind, randomised, placebo-controlled trial with an open-label extension". The Lancet. Neurology. 12 (12): 1141–1150. doi:10.1016/S1474-4422(13)70239-4. PMID24140442. S2CID35122538.{{cite journal}}: CS1 maint: overridden setting (link)