Published Studies

Four studies were conducted, 2 of which were double-blind comparisons of morphine plus oxycodone.

Blumenthal et al (Anesth. Anal., 2007:105, 233-237) evaluated the co-administration of Patient Controlled Analgesia (PCA) morphine plus oral oxycodone (CR) vs PCA morphine plus oral placebo in 40 lumbar discectomy patients for 2 days post-surgery. They found improved analgesic control (p<0.05) and reduced nausea/vomiting, as well as a significant shortening of the time to the first bowel movement (p<005) in patients receiving Dual Opioid® treatment than patients receiving PCA morphine.

Lauretti et al (Br. J. Cancer, 2003, 89: 2027-2030) compared the amount of opioid used and side effect incidence in a double-blind crossover in 22 cancer patients with moderate to severe pain when receiving monotherapy with either CR formulations of morphine or oxycodone. Rescue medication consisted of oral doses of IR morphine. In the oxycodone CR group, the amount of IR morphine rescue was reduced by 30-40% compared to the IR morphine rescue consumed by patients receiving CR morphine, suggesting that there was synergy when the Dual Opioid combination was used. Dual Opioid treatment was also accompanied by marked reductions in nausea and vomiting.

A similar multi-week open label study in cancer patients (Mercandante et al, Supportive Care Cancer, 2004, 12: 762-766) evaluating various combinations of mu agonist opioids in 14 cancer patients with poor pain control who were receiving monotherapy with fentanyl transdermal or methadone. Results showed that addition of graded amounts of oral morphine had a markedly diminished pain and reduced the need for further dose increases, without any appreciable increase in opioid related adverse events (AEs).

A multi-month double-blind study by Jamison et al (Spine, 1998: 23: 2591-2600) in 36 patients with chronic low back pain, demonstrated that patients taking flexible regimens of oxycodone plus morphine had substantially better pain control than subjects treated with oxycodone alone or naproxen alone—there were no appreciable increase in opioid related AEs in the Dual Opioid treated group relative to oxycodone alone.