Suspected Fentanyl or Synthetic Opioid — Emergency

When When sudden respiratory depression, unconsciousness, or pinpoint pupils occur after an unknown substance (suspected heroin, cut cocaine, counterfeit tablets, nitazenes).

Immediate

1. Call 112 — synthetic opioids act stronger and longer than naloxone.

2. Use naloxone nasal spray if available. If no effect after 2–3 minutes: second dose. With fentanyl/nitazenes, 3–4 doses may be needed.

3. Recovery position, keep airways clear. If breathing has stopped: chest compressions.

Don't do

Don't ration naloxone. Fentanyl overdoses need more naloxone than classic heroin.

Don't leave the person alone, even after naloxone has worked. Rebound respiratory depression from the prolonged duration of action is real.

Don't throw away leftover substance. If available, secure it for drug checking (e.g. Eclipse e.V.) — it can protect other users.

Fentanyl is 50–100× more potent than morphine. Carfentanil and nitazenes (e.g. isotonitazene, etonitazene) are another 10–100× more potent than fentanyl. Even traces in suspected heroin, cut cocaine, or counterfeit tablets (“Oxy”) can be fatal.

In Germany the market has so far been more stable than in North America, but in 2023–2025 there were increasing nitazene findings in the EUDA early warning system. Berlin: drugchecking.berlin (vista, Schwulenberatung, Fixpunkt) and Eclipse e.V. report suspicious findings immediately.

Naloxone can reverse fentanyl, but needs higher doses and repetition. For naloxone sources, see the opioid overdose scenario.

Low-threshold for users: fentanyl test strips are available through drug-checking services or online. Not reliable for nitazenes, but a sensible first step.