From the Guidelines
Naloxone can reverse the effects of nitazenes, but its effectiveness may be limited due to the high potency and binding affinity of nitazenes for opioid receptors. When responding to a suspected nitazene overdose, multiple doses of naloxone (2-4mg) may be required, and the patient should be closely monitored for at least 24 hours as the overdose effects can return after naloxone wears off 1. This is because nitazenes have a high binding affinity for opioid receptors and may outlast the effects of naloxone, which typically works for only 30-90 minutes.
Key Considerations
- Emergency medical services should always be called for suspected nitazene overdoses, even if naloxone initially appears effective.
- Healthcare providers should be prepared for the possibility of precipitated withdrawal symptoms when administering naloxone, which may be particularly severe with these potent synthetic opioids.
- The goal of naloxone administration should not be awakening but rather improved ventilatory effort, which can be a comparatively difficult outcome to assess 1.
Treatment Approach
- Supportive care, including attention to ventilation and oxygenation, is generally sufficient for managing patients who overdose on nitazenes.
- Naloxone should be administered using conventional criteria, but its effectiveness may be limited due to the high potency of nitazenes.
- Situations in which patients appear to have “naloxone-resistant overdose” frequently represent a polysubstance exposure or metabolic insults, such as hypoxia or hypercarbia 1.
From the Research
Nitazene Response to Naloxone
- Nitazenes are a group of potent synthetic opioids that have been increasingly prominent as novel psychoactive drugs in recent years 2.
- The effectiveness of naloxone in reversing the negative effects of opioids, including respiratory depression, varies depending on the pharmacokinetics and pharmacodynamics of the opioid that was overdosed 3.
- Studies have shown that naloxone can be effective in treating nitazene overdoses, with standard dosing regimens appearing to be effective in most cases 2, 4.
- A scoping review of naloxone and hospitalization reports in response to nitazene compound overdose found that most patients received high doses of naloxone and had relatively long hospital stays 4.
- Another study reported on two cases of nitazene intoxication in an Australian emergency department, where one patient responded positively to naloxone 5.
- The use of naloxone in treating nitazene overdoses is common, with a median total dose of intravenous naloxone within 1 hour post-hospital presentation of 400 μg 2.
- However, the potency and unpredictability of nitazenes pose a challenge for treatment, and more research is needed to understand the effectiveness of naloxone in reversing nitazene-induced respiratory depression 2, 4, 6.