Carfentanil (Grey death)

​Introduction

• One of the most potent opioids created, known as Wildnil.
• This was originally created to sedate large mammals.
• Commonly used as positron emission tomography scan radioligand

Pharmacology

• Carfentanil acts predominately on mu opioid receptors as a strong competitive agonist.
  • Opiate receptors are G-protein receptors in which binding of the opiate stimulates GTP -> GDP. This decreases the intracellular cAMP by inhibiting adenylate cyclase. This hyperpolarizes the cell and reduces neurotransmitter release.
• Biological half-life 7.7 hours
• Potency 10,000 times of morphine and 100 times of fentanyl.
• Formulation: 10ml vial at 3mg/mL
• 0.005-0.02 mg/kg given to animals for sedation

Clinical Toxicity

• Altered level of consciousness -> Coma
• Respiratory depression
• Miosis

Case Reports               

• Moscow theater hostage crisis
  • Russians responded by pumping “undisclosed chemical agent” into ventilation system
  • Some report naloxone was used as an antidote
  • Carfentanil was identified on the clothing of some victims
    
    

Laboratory Identification

• Will not be positive on routine opioid drug screen

 

• Felt not to cross react with fentanyl immunoassays
• Dedicated gas chromatopgraphy mass/spectrometry has been able to identify the drug as cause of death in certain case reports

Treatment/Management

• Naloxone
  • Mu opioid receptor inverse agonist
  • IV, IM, SubQ (onset of action 2-5 mins), Intranasal (onset of action 3-5 mins)
  • Biological half life elimination: Intranasal ~2 hours, IM, IV, SubQ 0.5-1.5 hours
  • Duration = 30-120 mins (IV shorter duration than IM)
  • Adult dosing 0.4-4mg, child dosing 0.1 mg/kg/dose, re-dosing every 2-3 minutes
  • Animal studies suggest dosing adequate response to proper dosing of naloxone to carfentanil ingestion
  • Consideration of naloxone gtt especially in highly potent opioids such as carfentanil
    • Can start gtt at X mg / hour that were needed to reach GCS 15
• Respiratory and hemodynamic support
  • Intubation
  • Vasopressors
• Observation Period
  • 2-4 hours 

Grey Death
 

• Looks like concrete mixing powder -> either chunky rock-like material or grey fine powder
• Combination drug of highly potent opioids including different mixtures of heroin, fentanyl, carfentanil, and U-47700
• Can be injected, inhaled, ingested, or absorbed through mucous membranes
  • Touching the powder does not result in direct intoxication
• Use routine universal precautions
  • Take caution if there are any breaks in skin

References1–7
1.             Milone MC. Laboratory testing for prescription opioids. J Med Toxicol. 2012;8(4):4086. doi:10.1007/s13181-012-0274-7.
2.             Moresco A, Larsen RS, Sleeman JM, Wild MA, Gaynor JS. USE OF NALOXONE TO REVERSE CARFENTANIL CITRATE-INDUCED HYPOXEMIA A CARDIOPULMONARY DEPRESSION IN ROCKY MOUNTAIN WAPITI (CERVUS ELAPHUS NELSONI). J Zoo Wildl Med. 2001;32(1):81-89. doi:10.1638/1042-7260(2001)032[0081:UONTRC]2.0.CO;2.
3.             Klebacher R, Harris MI, Ariyaprakai N, et al. Incidence of Naloxone Redosing in the Age of the New Opioid Epidemic. Prehospital Emerg Care. 2017:1-6. doi:10.1080/10903127.2017.1335818.
4.             Swanson DM, Hair LS, Strauch Rivers SR, et al. Fatalities Involving Carfentanil and Furanyl Fentanyl: Two Case Reports. J Anal Toxicol. 2017:1-5. doi:10.1093/jat/bkx037.
5.             Pathan H, Williams J. Basic opioid pharmacology: an update. Br J pain. 2012;6(1):11-6. doi:10.1177/2049463712438493.
6.             CARFENTANIL | C24H30N2O3 - PubChem. Available at: https://pubchem.ncbi.nlm.nih.gov/compound/carfentanil#section=Top. Accessed August 15, 2017.
7.             Feasel MG, Wohlfarth A, Nilles JM, Pang S, Kristovich RL, Huestis MA. Metabolism of Carfentanil, an Ultra-Potent Opioid, in Human Liver Microsomes and Human Hepatocytes by High-Resolution Mass Spectrometry. AAPS J. 2016;18(6):1489-1499. doi:10.1208/s12248-016-9963-5.
 


Authored by: Katie Lupez, MD