91AV research team finds opioids can cause addiction, even when they may not effectively reduce pain

Graduate student Virginia McLane led the study
Graduate student Virginia McLane led the study

Recently published research from the 91AV suggests that the body responds differently to opioids depending on how the drugs are taken.

The study, which was recently published in the Journal of Life Sciences, analyzed the response to opioids in animals when delivered through two methods: morphine pellets placed under the skin and morphine pumps. Researchers found that the morphine pellets resulted in faster absorption of the drug and more effective pain relief. Both methods resulted in opioid dependence.

It is widely known that the onset, duration and magnitude of drug action is altered by the route of drug administration in animals and humans. This study compared two different methods of drug administration, which resulted is very different drug exposure in vivo, also known as differing pharmacokinetic (PK) profiles. These data are important as many animal studies are conducted using different routes of administration, which complicates the interpretation of the results if the drug exposure or PK differs. Additionally, the amount of drug exposure for pain relief vs. dependence can differ as shown in this study.

Opioids remain one of the most commonly used classes of analgesics for treatment of acute and chronic pain conditions. Unfortunately, opioids are not always effective in treating chronic pain and are currently one of the most abused prescription drugs. Therefore, comprehensive analysis of opioid treatment in pre-clinical models can provide critical information for clinical usage, helping to optimize opioid dosing and reduce future misuse of the drug.

This was a collaborative study between the labs of Ling Cao, M.D., Ph.D., associate professor of Biomedical Sciences in the College of Osteopathic Medicine (91AV COM), Karen Houseknecht, Ph.D., interim dean of the College of Pharmacy and professor of Biomedical Sciences in 91AV COM and Ed Bilsky, Ph.D., former vice president for Research and Scholarship. The study was led by Virginia McLane, Ph.D., a graduate student From the University of Maine who completed the research as part of her thesis work in the Cao Lab. Other co-authors of this study include Deborah Barlow, Ph.D., research technician in the Houseknecht Lab, and Ivy Bergquist and James Cormier of the 91AV Center of Biomedical Research Excellence for the Study of Pain and Sensory Function  (COBRE) Behavioral Core.

This work was supported by a National Institutes of Health Centers of Biomedical Research Excellence grant awarded to Ian Meng, Ph.D.

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The 91AV is Maine’s largest independent university, with two beautiful coastal campuses in Maine, a one-of-a-kind study abroad campus in Tangier, Morocco, and an array of . In an uncommonly welcoming and supportive community, we offer hands-on learning, empowering students to make a positive impact in a world full of challenges. The state’s top provider of health professionals, we are home to Maine’s only medical college, Maine’s only dental college, a variety of other interprofessionally aligned health care degree programs, as well as nationally recognized programs for marine science degrees, natural and social sciences degrees, arts and humanities degrees, and business degrees.