Prehospital Outcomes Associated with an Initial Strategy of Intranasal versus Intramuscular Naloxone Administration by EMS Clinicians: A Nationwide Cohort Study
Smida et al · Prehospital Emergency Care · 2026
Retrospective Observational Analysis · ESO Data Collaborative · n = 16,550
resuscitation · toxicology · opioids · USA
Written by: Tyron Maartens
● Large sample size ● Multi-centre ● Retrospective ● Possible sampling bias
Naloxone administered intra-muscularly (IM) resulted in more rapid resolution of decreased level of consciousness and respiratory depression when compared to intra-nasally (IN), without any increase in adverse events. In patients with suspected opioid overdose without IV access, the IM route is a viable first-line approach to administer naloxone.
Naloxone is an opioid antagonist available to ALS practitioners to reverse suspected opioid overdose in the prehospital setting. It can be administered IV, IO, IM, and IN. Common practice worldwide (particularly in the USA) is for naloxone to be administered IN, as this can be done quickly and safely. The authors performed a retrospective analysis of a large cohort of patients managed by numerous EMS agencies in the USA who received both IN or IM naloxone and BVM ventilations by prehospital providers.
patients across 1 481 EMS agencies
of patients received naloxone IM as opposed to IN
rate of post-naloxone prehospital cardiac arrest
Patients who received IN naloxone were more likely to require at least one repeat dose of naloxone and received a higher total dose when compared to IM. Resolution of respiratory depression (defined as RR <12) and decreased level of consciousness (defined as GCS <12) were both more rapid in the IM naloxone group. There was a higher incidence of severe hypoxia (SpO2 <80%) in the IN naloxone group. There was no difference in the incidence of post-naloxone cardiac arrest or the incidence of precipitated opioid withdrawal requiring management (anti-emetics, chemical restraint, or physical restraint).
Some potential for bias exists in how patients were selected. Patients who received naloxone prior to EMS arrival were excluded, and only patients who received both BVM ventilation and naloxone were included. There was also no way to determine if patients were truly suffering from opioid overdose, and as such there was no way to compare the two groups’ baseline characteristics in this regard.
While not yet as prevalent as in the US, patients experiencing complications of opioid use are on the rise in South Africa. In patients with reduced level of consciousness or respiratory depression secondary to suspected opioid overdose, it appears that naloxone can be safely administered via the IM route, as opposed to the IN route. This may also result in more rapid resolution of symptoms, with no increase in the risk of adverse events. IM administration may be quicker and more readily available (practitioners may not always have access to a nasal atomiser), and thus provides a useful alternative to conventional teaching.
