Buprenorphine Affects the Initiation and Severity of Interleukin Induced Acute Pancreatitis in Mice.

Acute pancreatitis (AP) is a common disease with no targeted therapy and has varied outcomes ranging from spontaneous resolution to being lethal. While typically painful, AP can also be painless. Various agents, including opioids are used for pain control in AP; the risks, and benefits of which are often debated. Since experimental AP in mice is used to study the efficacy of potential therapies, we studied the effect of a commonly used opioid buprenorphine on the initiation and progression of AP. For this we administered extended-release buprenorphine subcutaneously prior to inducing the previously established severe AP model that uses Interleukins 12 and 18 (IL12,18) in genetically obese (ob/ob) mice and compared this to mice with AP but without the drug. Mice were monitored over 3 days and parameters of AP induction and progression were compared. Buprenorphine significantly reduced the serum amylase, lipase, pancreatic necrosis, and AP associated fat necrosis which is ubiquitous in obese mice and humans. Buprenorphine delayed the AP associated reduction of carotid artery pulse distention, and development of hypothermia, hastened renal injury, and muted the early increase in respiratory rate vs. IL12,18 alone. The site of buprenorphine injection appeared erythematous, inflamed, and microscopically showed thinning, loss of epidermal layers which had increased apoptosis. In summary, subcutaneous extended-release buprenorphine interfered with the induction of AP by reducing serum amylase, lipase, pancreatic and fat necrosis, the worsening of AP by delaying hypotension, hypothermia, while hastening renal injury, respiratory depression, and causing cutaneous injury at the site of injection.