Vadivelu, MD, N., Mitra, MD, S. and Hines, MD, R.L. 2018. Peripheral opioid receptor agonists for analgesia: A comprehensive review. Journal of Opioid Management. 7, 1 (Jan. 2018), 55–68. DOI:https://doi.org/10.5055/jom.2011.0049.