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Substance education guide

Carfentanil

Ultra-potent synthetic opioid · Fentanyl analogue · Veterinary wildlife tranquilizer

· How it works

Classification and primary mechanism

Carfentanil is a synthetic 4-anilidopiperidine and full mu-opioid receptor agonist with extreme receptor affinity. It has no accepted human medical use and is manufactured for large-animal immobilization. Its potency and rapid respiratory suppression make even microgram-scale exposure a medical emergency.

· Immediate effects

Recognize the effects

Signs of Use

  • Pinpoint pupils, sudden sedation, and emotional detachment
  • Unarousable stupor, inability to stand, or sudden collapse
  • Slow, shallow, gurgling, or absent breathing
  • Blue or gray skin, cold clammy skin, and wooden-chest rigidity
  • Bradycardia, coma, cardiac arrest, or rapid loss of consciousness

Short Term

  • Micro-trace exposure: abrupt analgesia, sedation, miosis, dry mouth, and falling blood pressure
  • Low exposure: loss of consciousness, stupor, airway obstruction, and severe bradycardia
  • Toxic exposure: apnea, cyanosis, chest-wall rigidity, cardiac arrest, and brain injury within minutes
  • Naloxone may require repeated doses and continuous hospital monitoring
  • Do not assume a stimulant effect protects against opioid respiratory arrest

Long Term

  • Permanent anoxic brain injury after a nonfatal overdose
  • Severe opioid tolerance and physical dependence
  • Protracted withdrawal with vomiting, dehydration, pain, and autonomic instability
  • Infectious and traumatic harms from contaminated or injected products

· Long-term consequences

Immediate respiratory arrest

Call 911, administer naloxone repeatedly while supporting breathing, and provide rescue breaths about every five seconds with a barrier device. A person may relapse into respiratory depression after naloxone wears off.

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