Carfentanil, a synthetic opioid, is an analog of fentanyl that is approximately 100 times more potent than its predecessor and 10,000 times more potent than morphine (NIDA, 2021). Originally designed as a tranquilizer for large animals, such as elephants, under the name Wildner, its extreme potency makes it highly dangerous for human use. Despite this risk, drug dealers still continue to use it in the black market to boost the strength of other drugs.
History
Carfentanil was first synthesized in 1974 by chemists at Janssen Pharmaceuticals during research on fentanyl derivatives (Stanley, 1992). It was specifically designed for veterinary use to immobilize large animals due to its extreme potency. Its entry into illicit markets, however, has contributed to the opioid crisis, as even trace amounts can cause fatal overdoses (DEA, 2021).
Legality in Various Countries
The legal status of carfentanil varies significantly across countries:
- United States: Classified as a Schedule II controlled substance under the Controlled Substances Act, indicating high abuse potential with limited veterinary use (DEA, 2021).
- Canada: Listed under Schedule I of the Controlled Drugs and Substances Act (UNODC, 2021).
- United Kingdom: Regulated as a Class A drug under the Misuse of Drugs Act (UNODC, 2021).
- Australia: Classified as a Schedule 9 drug, indicating prohibited substances except for specific medical or scientific research (UNODC, 2021).
Appearance/Odor
Carfentanil typically appears as a white or off-white crystalline powder and is odorless. It is often mixed with other substances, making it difficult to identify in illicit forms (DEA, 2021).
How Is It Made?
Carfentanil is synthesized using precursor chemicals such as N-phenethyl-4-piperidone (NPP) and other reagents. Legitimate production occurs in highly regulated laboratories for veterinary use, while illicit synthesis often involves clandestine operations, primarily in China and Mexico (UNODC, 2021).
Pharmacokinetics
Carfentanil is lipophilic (lipid loving), allowing it to rapidly cross the blood-brain barrier. It has a very short half-life in humans, estimated at 1–2 hours, which makes it extremely potent but also rapidly metabolized, complicating overdose interventions (Nelson & Hoffman, 2020).
Pharmacodynamics
Carfentanil acts as a full agonist at the μ-opioid receptor, producing profound analgesia, sedation, and respiratory depression. Its potency is attributed to its high receptor affinity and ability to penetrate the central nervous system quickly (Nelson & Hoffman, 2020).
Routes of Administration
Carfentanil can be administered in several ways:
- Veterinary Use: Intramuscular injection.
- Illicit Use: Intravenous, intranasal, or oral ingestion, often mixed with other drugs like heroin or cocaine (CDC, 2022).
What Are The Effects of Carfentanil?
Therapeutic Effects
- Immobilization of large animals (veterinary use).
Adverse Effects
- Euphoria
- Analgesia
- Respiratory depression
- Loss of consciousness
- Bradycardia
- Seizures
- Death from overdose (CDC, 2022).
Speed of Onset
Carfentanil acts almost immediately when administered intravenously, with effects beginning within minutes. Other routes, such as intranasal or oral, have slightly slower onset times but remain rapid due to the drug’s lipophilicity (Nelson & Hoffman, 2020).
How Long Does Carfentanil Last?
The duration of effects is short, typically lasting 30–60 minutes, but its metabolites may remain in the body for longer periods, contributing to prolonged toxicity risks (Stanley, 1992).
How Long Does Carfentanil Stay In Your System?
Carfentanil can be detected using advanced laboratory techniques such as gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-tandem mass spectrometry (LC-MS/MS).
- Urine: Detectable for 24–48 hours.
- Blood: Detectable for up to 24 hours.
- Hair: Detectable for up to 90 days (DEA, 2021).
Cutoff levels depend on the testing method, with most urine assays detecting concentrations as low as 0.1 ng/mL.
Supply Chain Precursor/Sources/Locations
Legitimate production of carfentanil relies on controlled environments, while illicit synthesis often involves precursor chemicals sourced from:
- China: A major supplier of synthetic opioid precursors.
- Mexico: Clandestine labs producing finished carfentanil for export to the U.S. and other markets (UNODC, 2021).
How Much Does Carfentanil Cost?
Its often sold as an adulterant in heroin or counterfeit pills. Street prices vary but are typically $10–$20 per dose due to its extreme potency and low production cost (DEA, 2021).
How Much Is a Typical Dose?
A typical illicit dose of carfentanil is often measured in micrograms, since even 20 micrograms can be lethal. For comparison, a grain of salt weighs approximately 60 micrograms (NIDA, 2021).
User Demographics/Statistics
- Age: Illicit use is most common among individuals aged 18–45 (CDC, 2022).
- Gender: Higher prevalence among males.
- Geography: Most prevalent in North America, where the opioid epidemic has hit hardest (DEA, 2021).
Feedback on User Satisfaction/Experiences
Recreational users seeking a stronger “high” often report euphoric effects but also experience severe adverse reactions, including near-fatal overdoses. Medical professionals strongly advise against any non-prescribed use due to the drug’s extreme risks (NIDA, 2021).
Carfentanil vs. Fentanyl
- Potency: Carfentanil is approximately 100 times more potent than fentanyl (Stanley, 1992).
- Use: Carfentanil is limited to veterinary applications, while fentanyl has medical applications in humans (DEA, 2021).
- Risk: Carfentanil poses a significantly higher overdose risk due to its potency.
Carfentanil vs. Heroin
- Potency: Carfentanil is 50 times more potent than heroin (NIDA, 2021).
- Risk: Heroin users often unknowingly ingest carfentanil, leading to fatal overdoses (CDC, 2022).
Carfentanil vs. Morphine
- Potency: Carfentanil is 10,000 times more potent than morphine (Stanley, 1992).
- Duration: Morphine offers longer-lasting pain relief compared to carfentanil’s rapid but short-lived effects (Nelson & Hoffman, 2020).
Conclusion
Carfentanil’s extreme potency and rapid onset make it a significant contributor to the opioid crisis. While its legitimate uses in veterinary medicine are well-documented, its presence in illicit drug markets poses an unparalleled risk to public health. Understanding carfentanil’s pharmacology, effects, and dangers is critical for combatting its misuse and reducing opioid-related deaths.
References
- National Institute on Drug Abuse (NIDA). (2021). Fentanyl and other synthetic opioids drug facts. Retrieved from https://nida.nih.gov/research-topics/fentanyl
- Drug Enforcement Administration (DEA). (2021). Carfentanil: A dangerous synthetic opioid. Retrieved from https://www.dea.gov/factsheets/carfentanil
- Stanley, T. H. (1992). The history and development of the fentanyl series. Journal of Pain and Symptom Management, 7(3), 126–136. Retrieved from https://pubmed.ncbi.nlm.nih.gov/1517629/
- Centers for Disease Control and Prevention (CDC). (2022). Opioid overdose: Understanding the epidemic. Retrieved from https://www.cdc.gov/drugoverdose/epidemic/
- United Nations Office on Drugs and Crime (UNODC). (2021). Global synthetic drug trends. Retrieved from https://www.unodc.org/unodc/en/synthetic-drugs/index.html
- Nelson, L. S., & Hoffman, R. S. (2020). Fentanyl and other synthetic opioids: A comprehensive review. New England Journal of Medicine, 382(5), 465–477. Retrieved from https://www.nejm.org/doi/full/10.1056/NEJMra1802458
