133 © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 K. Rajput et al. (eds.), Pain Control in Ambulatory Surgery Centers, https://doi.org/10.1007/978-3-030-55262-6_11 Opioid Use in the Treatment of Pain States Ethan Williamson, Kelley L. Sharp, and Steven D. Waldman Abstract Opioid medications are used ubiquitously in the treatment of moderate and severe pain. They are a safe, convenient, and reliable method used to alleviate pain related to cancer and should be considered frst-line therapies. This chapter will discuss safe prescribing guidelines, practical applications of opioid medications, common medications used, strategies for the management of adverse effects, and methods of effectively achieving optimal analgesia in patients suffering from pain related to cancer. It will also offer more nuanced recommendations of treatment as they may relate to specifc sub- populations of patients and specifc medica- tions used in their treatment. Introduction Every year millions of people are diagnosed with cancer. Of those diagnosed with cancer, 66% will survive for at least 5 years, and 40% will live more than 10 years after their initial diagnoses [1, 2]. Pain is the most common symptom of cancer [3], reported in 59% of patients undergoing can- cer treatment, in 64% of patients with advanced disease, and in 33% of patients after treatment concludes [4–6]. Additionally, pain is one of the symptoms that patients fear most. More than three decades have passed since the WHO guidelines for cancer pain relief were pub- lished, but signifcant inadequacies remain in the relief of cancer-related pain. It is reported that more than one third of cancer patients suffering from pain are undertreated likely due to inade- quate attention to pain during treatment and delayed access to opioid medications [7, 8]. Uncontrolled pain can lead to signifcant morbid- ity for cancer patients, resulting in physical dis- abilities, emotional distress, and a reduced quality of life. As such, improving the patient experience with cancer-related pain is of signifcant impor- tance. Proper attention must be given to the patient’s expressed needs, goals of care, and physical condition so that appropriate measures are taken to ensure optimal pain control while minimizing adverse effects experienced by the patient [9]. Opioid analgesics have been, and continue to be, a safe and effective tool to manage chronic cancer pain. They are broadly used for the reduc- tion of cancer-related pain due to their known safety, ease of dose titration, multiple routes of E. Williamson · S. D. Waldman (*) University of Missouri – Kansas City School of Medicine, Kansas City, MO, USA e-mail: waldmans@umkc.edu K. L. Sharp Frank H. Netter School of Medicine – Quinnipiac University, North Haven, CT, USA 11