Okamoto, BP, Y., Tsuneto, MD, PhD, S., Tsugane, PhD, M., Takagi, PhD, T., & Uejima, PhD, E. (2018). A retrospective chart review of opioid-induced nausea and somnolence on commencement for cancer pain treatment. Journal of Opioid Management, 6(6), 431–434. https://doi.org/10.5055/jom.2010.0041