Naloxone Has Limitations for Reversing ODs From Fentanyl, Sufentanil

MONDAY, April 20, 2026 (HealthDay News) -- Naloxone has limitations for reversing overdoses from fentanyl and sufentanil, gradually reversing respiratory depression, but with variable reversal times, according to a study published in the May issue of Anesthesiology.Maarten A. van Lemmen, Ph.D., from the Leiden University Medical Center in the Netherlands, and colleagues conducted a prospective, crossover trial involving 12 opioid-naive individuals and 18 daily opioid users who received continuous fentanyl or sufentanil infusions, titrated to achieve 30 to 40 percent reduction in minute ventilation (V̇E). During steady-state respiratory depression, participants were administered Narcan (4 mg intranasal naloxone).The researchers found that within two to four minutes, Narcan restored V̇E across all participants but showed delayed reversal of end-tidal carbon dioxide concentration (pCO2; 11 to 17 minutes); eight opioid-naive individuals and 10 daily opioid users had pCO2 recovery during sufentanil exposure. V̇E reversal/onset times were zero to one minute in hysteresis analysis, and end-tidal pCO2 times were two to 11 minutes. Seven of 18 daily opioid users participated only once in the study due to withdrawal symptoms."Our study shows that the current doses of naloxone may not be sufficient to reverse overdoses caused by newer synthetic opioids," van Lemmen said in a statement. "We hope these findings encourage institutions to update guidelines and reinforce the importance of fast emergency intervention."One author disclosed ties to the pharmaceutical industry.Abstract/Full Text.Sign up for our weekly HealthDay newsletter

Naloxone Has Limitations for Reversing ODs From Fentanyl, Sufentanil

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