Nano-steps in altered opioid pharmacokinetics: a perspective on potential drug delivery post-bariatric surgery applications

Despite being a transformative intervention in treating obesity, bariatric surgery, encompassing procedures like Roux-en-Y gastric bypass and vertical sleeve gastrectomy, presents unique challenges in postoperative pain management due to altered pharmacokinetics in both adult and pediatric populations. Opioid medication, while being effective, poses risks of addiction and life-threatening side effects, thus, inviting alternative therapeutic approaches. Nanotechnology holds promise as it provides targeted solutions via nano-drug delivery systems, thereby reducing adverse effects and enhancing efficacy in an altered gastrointestinal system. Different methods, including subcutaneous and nasal delivery systems, prolong drug release, offer potential alternatives for patients with modified drug absorption and metabolism, as demonstrated by in vivo and in vitro studies investigating tramadol, ketamine, fentanyl, buprenorphine and others. Currently, safety issues associated with nanocarriers hinder their clinical deployment. This review prompts a new perspective on nano-controlled release methods and their applications in opioid analgesia, indicating that nanotechnology could address the pharmacokinetic challenges in pain management post-bariatric surgery. Alternative strategies, including the use of endogenous neuropeptides, are discussed for mitigating opioid-related complications and improving pain management outcomes.