Oncology nurses frequently administer opioid analgesics to patients experiencing pain. Opioid-naïve patients requiring increased or high-dose opioids must be monitored closely for sedation and respiratory depression. Unresponsive patients with pinpoint pupils and respiratory rates less than eight breaths per minute are candidates for treatment with naloxone, an opioidantagonist. Naloxone must be administered carefully to prevent acute withdrawal syndrome and the return of severe pain. Armed with knowledge about the action and effects of naloxone, nurses can better care for patients experiencing opioidinduced respiratory depression and promote patient safety.