Patient selection:
(1) high concentration of an opioid analgesic (following a high dose or if there is impaired excretion)
(2) significant sedation or respiratory depression
(2a) respirations < 8 breaths per minute
(2b) shallow respirations
(2c) oxygen saturation < 92%
(2d) difficulty rousing the patient
Patient management:
(1) Monitor the patient, including use of pulse oximetry.
(2) Consider administration of supplemental oxygen by nasal cannula. Severe respiratory depression may require intubation and mechanical ventilation.
(3) Administer naloxone slowly at a rate of 0.4 to 2.0 mg IV (or IM or SC) every 2-3 minutes until the adverse effect starts to reverse. If no response is seen after the administration of 10 mg, then reconsider the diagnosis of opioid toxicity.
(4) The patient may experience increased pain as the naloxone is given and a non-opioid analgesic may be needed.
(5) Naloxone has a relatively short half-life. If the opioid has an intermediate to long half-life, then multiple doses of naloxone may need to be given.
(6) If the opioid has a very long half-life (methadone, fentanyl patch), then a naloxone drip may be necessary.
Naloxone may be ineffective for some opioids such as buprenorphine. Higher doses of naloxone may be needed to reverse the effects of partial agonists.
