P-064 - Subcutaneous Opioids: Under the Skin Irritation or New Standard of Care?

Abstract Title: Subcutaneous Opioids: Under the Skin Irritation or New Standard of Care?

Background: Opioids can be administered via many routes including but not limited to oral, subcutaneous, and intravenous. While subcutaneous opioid injections have demonstrated safety and efficacy in many patient populations for decades, the oral and intravenous routes remain the most common routes of opioid administration in hospitalized patients. All opioids, regardless of the route administered have the potential to cause adverse effects, though opioids administered via the oral and subcutaneous routes may offer a decreased risk of adverse effects such as nausea, hypotension, and respiratory depression compared to those administered intravenously.

Purpose/Objectives: This quality improvement study implemented a revised standard of practice for opioid routes of administration and provided interdisciplinary education on opioid safety and appropriate use of subcutaneous opioids. The revised standard of practice favored administration of opioids via the oral route in all patients able to tolerate oral intake. In patients unable to tolerate oral intake or who required more rapid analgesia, the parenteral route was encouraged. Of the parenteral routes, subcutaneous was preferred; however, intravenous opioids remained available if deemed appropriate by the provider.


Methods: This pre-post pilot study occurred on a closed 24-bed comprehensive adult general medicine unit at a large community teaching hospital. The primary objective evaluated change in the mean number of opioids administered via the intravenous and subcutaneous routes. Secondary outcomes evaluated change in the mean opioid administrations, oral morphine equivalents, and daily patient-reported pain scores. All primary and secondary outcomes were evaluated per patient day during the first five days of admission to the select unit. Because the subcutaneous route was not commonly utilized prior to this pilot study, education on subcutaneous opioid administration was provided to the interdisciplinary team prior to implementation of the revised standard of practice. Data three months prior to and six months following the intervention was collected and compared to determine primary and secondary outcomes.


Results: The pre- and post-intervention groups consisted of 307 and 176 patients, respectively. Groups were similar in age, BMI, and race; however, the post-intervention group had a higher ratio of females than males. Following the intervention, we observed a decrease in mean number IV opioid administrations (2.4 [1.7] vs. 1.6 [0.8], p=0.003) and increase in mean number of subcutaneous opioid administrations per day. Additionally, patients in the post-intervention group received fewer opioid administrations (2.7 [2.0] vs. 2.4 [1.4], p=0.142) and total oral morphine equivalents (28.9 [33.3] vs. 25.6 [24.9], p=0.273) per patient day. Total morphine equivalents were further broken down into those administered via parenteral (intravenous and subcutaneous), intravenous, subcutaneous, and oral routes. The post-intervention group demonstrated a statistically significant decrease in parenteral (27.5 [29.0] vs.18.4 [15.9], p=0.012) and intravenous (27.5 [29.0] vs 14.3 [9.4], p < 0.001) oral morphine equivalents per patient day and an increase in subcutaneous and oral (21.9 [19.9] vs. 22.8 [21.5], p=0.667) oral morphine equivalents per patient day. Despite less total oral morphine equivalents, patients in the post-intervention group also had lower pain scores on all 5 days, with a statistically significant decrease in pain scores seen on day 1 (5.0 [2.9] vs. 4.5 [3.0], p=0.039) and day 5 (4.3 [2.5] vs. 3.3 [2.2], p=0.004).

Conclusions/Implications for future research and/or clinical care: Opioid education and implementation of a revised standard of practice reduced exposure to intravenous opioids and decreased patient-reported pain scores despite receiving fewer oral morphine equivalents per patient day.


References: Ackerman AL, et al. Association of an opioid standard of practice intervention with intravenous opioid exposure in hospitalized patients. JAMA Intern Med. 2018.

Daoust R, et al. Impact of age, sex, and route of administration on adverse events after opioid treatment in the emergency department. A retrospective study. Pain Res. Manag. 2015;20(1):23-28.

Safavi M, et al. Postoperative analgesia after caesarean section: intermittent intramuscular versus subcutaneous morphine boluses. Acute pain. 2007;9(4):215-9.

Parsons HA, et al. Intermittent subcutaneous opioids for the management of cancer pain. J Palliat Med. 2008;11(10):1319-24.

Radbrunch L, et al. Systematic review of the role of alternative application routes for opioid treatment for severe cancer pain. Palliat Med. 2011;25(5):578-96.