Background: Naloxone is an opioid antagonist that works to treat opioid overdose. Few randomized trials have assessed the efficacy of intranasal administration, whereas more data have been published supporting use of intramuscular naloxone. This prospective trial examines the ability of the same dose (800 mcg per 1 mL solution) of intranasal naloxone vs. intramuscular naloxone at managing opioid overdose.
Study design: Double-blind double-dummy randomized clinical trial.
Setting: Single supervised injection center in Sydney.
Synopsis: In this study, 197 participants with opioid overdose were randomized to intramuscular or intranasal naloxone. If the patient did not respond to either (GSC score less than 13, RR less than 10, or oxygen saturation less than 95%), a rescue dose of intramuscular naloxone was given. Participants who received the intramuscular naloxone were less likely to need the rescue dose (8.6% vs. 23.1%; odds ratio, 0.35; P = .002). The time to achieve an RR greater than 10 (15 vs. 8 minutes) and GSC score greater than 13 (17 vs. 8 minutes) was longer in the intranasal than the intramuscular group. Limitations include the setting of a controlled environment. Also, this protocol called for an initial 5 minutes of ventilation prior to randomization, which selected for more severe overdose cases in the overall study population. More studies are needed to assess efficacy in the field, needlestick injuries, and larger intranasal doses.
Bottom line: Intranasal naloxone effectively reverses opioid overdose but not as effectively as intramuscular naloxone at the same dose.
Citation: Dietze P et al. Effect of intranasal vs intramuscular naloxone on opioid overdose: A randomized clinical trial. JAMA Netw Open. 2019;2:e1914977. doi: 1
Dr. Welter is a hospitalist at Northwestern Memorial Hospital and instructor of medicine, Feinberg School of Medicine, both in Chicago.