Researchers conducted a randomized, controlled, double-dummy, blinded, non-inferiority trial, with the aim of measuring and evaluating clinical response to nasal naloxone in opioid overdoses in the prehospital environment.

• Men and women aged above 18 years with miosis, rate of respiration ≤ 8/min, and Glasgow Coma Score < 12/15 were randomized to a commercially available 1.4 mg/0.1 mL intranasal naloxone or 0.8 mg/2 mL naloxone administered intramuscularly.

• In the per-protocol population, analysis of 201 participants was done.

• In 196 cases, heroin was suspected.

• Relative to 0.8 mg intramuscular naloxone, intranasal naloxone (1.4 mg/0.1 mL) was identified as less efficient for return to spontaneous breathing within 10 minutes in overdose patients in the prehospital environment when compared head-to-head.

• Eighty percent of the participants had restored breathing after receiving one dose of intranasal naloxone at 1.4 mg/0.1 mL with few mild adverse reactions.