Physical Compatibility of Four Opioid Analgesics with 64 Intravenous Drugs Commonly Used in Palliative Care During Simulated Y-Site Administration

<b><i>Background:</i></b> Co-administration of multiple intravenous drugs via the Y-site is common in palliative care. Information on the compatibility of opioid analgesics with intravenous drugs commonly used in palliative care is lacking. <b><i>Objective:</i></b> We aimed to determine the physical compatibility of 4 opioid analgesics with 64 drugs during simulated Y-site administration. <b><i>Design:</i></b> Four opioid analgesics and intravenous drugs were prepared using 0.9% sodium chloride solution or water for injection, without dilution, according to the manufacturer's recommendations (morphine hydrochloride, oxycodone hydrochloride, fentanyl citrate, and hydromorphone hydrochloride concentrations: 10, 10, 0.05, and 1 mg/mL, respectively). <b><i>Measurements:</i></b> In the compatibility tests, the opioid analgesics and target drugs were mixed in an equal volume ratio; the appearance, turbidity, and pH were evaluated immediately, one and four hours after mixing. Incompatibility was defined as change in appearance (turbidity increase ≥0.5 nephelometric turbidity units, Tyndall effect, visual judgment) and pH change ≥10%. Incompatible combinations were retested using dilutions of either opioid analgesics or the target drug. <b><i>Results:</i></b> Of the 255 combinations, 26 (10%) were defined as incompatible, including 12 morphine hydrochloride, 11 oxycodone, and 3 hydromorphone combinations involving 15 target drugs. Of the 28 retests conducted by diluting drugs in the combinations determined to be incompatible, the combinations of omeprazole (0.2 mg/mL) and lansoprazole (0.3 mg/mL) with morphine hydrochloride (1 mg/mL) remained incompatible. <b><i>Conclusions:</i></b> Utilization of these compatibility data for morphine hydrochloride, oxycodone, fentanyl, and hydromorphone in clinical practice should help guide safer drug administration and influence the selection of IV combinations in palliative care settings.