Use and efficacy of nebulized naloxone in patients with suspected opioid intoxication.

Objective: To describe the use and efficacy of nebulized naloxone in patients with suspected opioid intoxication.

Methods: This was an observational study conducted at an inner city emergency department. Patients were eligible if they had self-reported or suspected opioid intoxication and a spontaneous respiratory rate ≥6 breaths/minute. Nebulized naloxone (2 mg in 3 mL normal saline) was administered through a standard face mask at the discretion of the treating physician. Structured data collection included demographics, vital signs pre and post naloxone administration and adverse events. The primary outcome was level of consciousness, which was recorded pre and 15 minutes postnaloxone administration using the Glasgow Coma Scale (GCS) and the Richmond Agitation Sedation Scale (RASS).

Results: Of the 73 patients who presented with suspected opioid intoxication and were given naloxone over the study period, 26 were initially treated with nebulized naloxone. After nebulized naloxone administration, median GCS improved from 11 [interquartile range (IQR) 3.5] to 13 (IQR, 2.5), P = .001. Median RASS improved from -3.0 (IQR, -1.0) to -2.0 (IQR, -1.5), P < .0001. Need for supplemental oxygen decreased from 81% to 50%, P = .03. Vital signs did not differ pre/post therapy. There were few adverse effects from nebulized naloxone administration: 12% experienced moderate-severe agitation, 8% were diaphoretic and none vomited. Eleven required subsequent administrations of naloxone, nine of whom self-reported using either heroin, methadone or both. Of these, 5 underwent urine drug screening and all 5 tested positive for either opiates or methadone.

Conclusions: Nebulized naloxone was well-tolerated and led to a reduction in the need for supplemental oxygen as well as improved median GCS and RASS scores in patients with suspected opioid intoxication.