Products
In many countries, no drugs containing carfentanil are on the market. The active ingredient is used in veterinary medicine (Wildnil). Legally, it belongs to narcotics.
Structure and properties
Carfentanil (C24H30N2O3, Mr = 394.5 g/mol) is structurally closely related to fentanyl, being 4-methoxycarbonylfentanyl. Carfentanil citrate is present in pharmaceuticals. The active ingredient was developed at Janssen in the 1970s and is also known as carfentanyl in German.
Effects
Carfentanil has opioid, anesthetic, psychotropic, analgesic, and depressant properties. The effects are due to binding to μ-opioid receptors. Carfentanil is extremely potent – potency is about 10,000 times greater than that of morphine and about 100 times greater than that of fentanyl. It is therefore used exclusively as a veterinary drug for large animals such as brown bears, polar bears, bison, deer, elk, rhinoceroses and elephants. Carfentanil is not used in human medicine.
Indications
In veterinary medicine for anesthesia and immobilization of large animals.
Dosage
According to the SmPC. The drug is usually administered intramuscularly with an anesthetic dart. It is often combined with other agents, such as xylazine.
Abuse
Carfentanil is abused as an illegal narcotic and to stretch drugs. This is life-threatening because of its high potency. Numerous deaths have been reported. The DEA issued a strong warning against its use in 2016. During the hostage crisis in Moscow’s Dubrovka Theater in October 2002, carfentanil was used by special military units to rescue hostages. The agent, along with remifentanil, was introduced into the theater as an aerosol before the storming. This was done with the intention of stunning the hostage-takers. However, the consequences of this use also killed over 120 of the 850 hostages (Wax et al., 2003, Riches et al., 2012).
Adverse effects
In the event of abuse or accidental contact, life-threatening poisoning can occur rapidly. Possible symptoms include central depression, respiratory depression, respiratory failure, and coma. The drug must be handled with great care. Opioid antagonists such as naloxone are available as antidotes.