Carfentanil
Encyclopedia
Carfentanil or carfentanyl (R-33799) is an analogue of the popular synthetic opioid
analgesic
fentanyl, and is one of the most potent opioids known (also the most potent opioid used commercially). Carfentanil was first synthesized in 1974 by a team of chemists at Janssen Pharmaceutica
which included Paul Janssen
. It has a quantitative potency approximately 10,000 times that of morphine
and 100 times that of fentanyl, with activity in humans starting at about 1 microgram
. It is marketed under the trade name Wildnil as a general anaesthetic
agent for large animals. Carfentanil is intended for animal use only as its extreme potency makes it inappropriate for use in humans. Currently sufentanil
, approximately 10-20 times less potent (500 to 1000 times the efficacy of morphine per weight) than carfentanil, is the maximum strength fentanyl analog for use in humans.
A good practical example of the drug in use in veterinary practice was shown in an episode of the Discovery Channel
series, Animal Cops: Houston, where carfentanil was administered orally (dissolved in honey, specifically) to a full-grown brown bear
to tranquilize it so that it could be safely relocated to the Houston Zoo
from a south Texas animal abuser's property.
, the Russia
n military made use of an aerosol form of either carfentanil or another similar drug such as 3-methylfentanyl
to subdue Chechen
hostage takers. Its short action, easy reversibility and therapeutic index
(10600 vs. 300 for fentanyl) would make it a potential agent for this purpose. Wax et al. surmise from the available evidence that the Moscow
emergency services had not been informed of the use of the agent, but were instructed to bring opioid antagonists. Because of the lack of information provided, the emergency workers did not bring adequate supplies of naloxone
or naltrexone
(opioid antagonist
s) to prevent complications in many of the victims. Assuming that carfentanil was the only active constituent (which has not been verified by the Russian military), the primary acute toxic effect to the theatre victims would have been opioid-induced apnea
; in this case mechanical ventilation
and/or treatment with opioid antagonists would have been life-saving for many or all victims.
Opioid
An opioid is a psychoactive chemical that works by binding to opioid receptors, which are found principally in the central and peripheral nervous system and the gastrointestinal tract...
analgesic
Analgesic
An analgesic is any member of the group of drugs used to relieve pain . The word analgesic derives from Greek an- and algos ....
fentanyl, and is one of the most potent opioids known (also the most potent opioid used commercially). Carfentanil was first synthesized in 1974 by a team of chemists at Janssen Pharmaceutica
Janssen Pharmaceutica
Janssen Pharmaceutica is pharmaceutical company, established in Belgium in 1953 by Paul Janssen. Its headquarters are located in Beerse, in the Campine region of the province of Antwerp, Belgium. It was created not as a subsidiary of a chemical factory but solely with the aim of conducting...
which included Paul Janssen
Paul Janssen
Paul Adriaan Jan, Baron Janssen was the founder of Janssen Pharmaceutica, a pharmaceutical company with over 20,000 employees. In 2005 he finished as runner up, after Father Damien, in the poll for The Greatest Belgian organized by the regional Flemish television...
. It has a quantitative potency approximately 10,000 times that of morphine
Morphine
Morphine is a potent opiate analgesic medication and is considered to be the prototypical opioid. It was first isolated in 1804 by Friedrich Sertürner, first distributed by same in 1817, and first commercially sold by Merck in 1827, which at the time was a single small chemists' shop. It was more...
and 100 times that of fentanyl, with activity in humans starting at about 1 microgram
Microgram
In the metric system, a microgram is a unit of mass equal to one millionth of a gram , or 1/1000 of a milligram. It is one of the smallest units of mass commonly used...
. It is marketed under the trade name Wildnil as a general anaesthetic
General anaesthetic
A general anaesthetic is a drug that brings about a reversible loss of consciousness. These drugs are generally administered by an anaesthesia provider to induce or maintain general anaesthesia to facilitate surgery...
agent for large animals. Carfentanil is intended for animal use only as its extreme potency makes it inappropriate for use in humans. Currently sufentanil
Sufentanil
Sufentanil is a powerful synthetic opioid analgesic drug, approximately 5 to 10 times more potent than its analog, fentanyl. Sufentanil is marketed for use by specialist centres under different trade names, such as Sufenta and Sufentil...
, approximately 10-20 times less potent (500 to 1000 times the efficacy of morphine per weight) than carfentanil, is the maximum strength fentanyl analog for use in humans.
A good practical example of the drug in use in veterinary practice was shown in an episode of the Discovery Channel
Discovery Channel
Discovery Channel is an American satellite and cable specialty channel , founded by John Hendricks and distributed by Discovery Communications. It is a publicly traded company run by CEO David Zaslav...
series, Animal Cops: Houston, where carfentanil was administered orally (dissolved in honey, specifically) to a full-grown brown bear
Brown Bear
The brown bear is a large bear distributed across much of northern Eurasia and North America. It can weigh from and its largest subspecies, the Kodiak Bear, rivals the polar bear as the largest member of the bear family and as the largest land-based predator.There are several recognized...
to tranquilize it so that it could be safely relocated to the Houston Zoo
Houston Zoo
The Houston Zoo is a zoological park located within Hermann Park in Houston, Texas, United States. Housing over 6,000 animals belonging to over 900 species, the zoo receives 1.6 million visitors each year and is the seventh most visited zoo in the nation...
from a south Texas animal abuser's property.
Moscow theater hostage crisis
Allegedly, during the 2002 Moscow theater hostage crisisMoscow theater hostage crisis
The Moscow theater hostage crisis, also known as the 2002 Nord-Ost siege, was the seizure of the crowded Dubrovka Theater on 23 October 2002 by some 40 to 50 armed Chechens who claimed allegiance to the Islamist militant separatist movement in Chechnya. They took 850 hostages and demanded the...
, the Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
n military made use of an aerosol form of either carfentanil or another similar drug such as 3-methylfentanyl
3-Methylfentanyl
3-Methylfentanyl is an opioid analgesic that is an analogue of fentanyl. 3-Methylfentanyl is one of the most potent drugs that has been widely sold on the black market, estimated to be between 400-6000 times stronger than morphine depending on which isomer is used .3-Methylfentanyl was first...
to subdue Chechen
Chechnya
The Chechen Republic , commonly referred to as Chechnya , also spelled Chechnia or Chechenia, sometimes referred to as Ichkeria , is a federal subject of Russia . It is located in the southeastern part of Europe in the Northern Caucasus mountains. The capital of the republic is the city of Grozny...
hostage takers. Its short action, easy reversibility and therapeutic index
Therapeutic index
The therapeutic index is a comparison of the amount of a therapeutic agent that causes the therapeutic effect to the amount that causes death or toxicity ....
(10600 vs. 300 for fentanyl) would make it a potential agent for this purpose. Wax et al. surmise from the available evidence that the Moscow
Moscow
Moscow is the capital, the most populous city, and the most populous federal subject of Russia. The city is a major political, economic, cultural, scientific, religious, financial, educational, and transportation centre of Russia and the continent...
emergency services had not been informed of the use of the agent, but were instructed to bring opioid antagonists. Because of the lack of information provided, the emergency workers did not bring adequate supplies of naloxone
Naloxone
Naloxone is an opioid antagonist drug developed by Sankyo in the 1960s. Naloxone is a drug used to counter the effects of opiate overdose, for example heroin or morphine overdose. Naloxone is specifically used to counteract life-threatening depression of the central nervous system and respiratory...
or naltrexone
Naltrexone
Naltrexone is an opioid receptor antagonist used primarily in the management of alcohol dependence and opioid dependence. It is marketed in generic form as its hydrochloride salt, naltrexone hydrochloride, and marketed under the trade names Revia and Depade...
(opioid antagonist
Receptor antagonist
A receptor antagonist is a type of receptor ligand or drug that does not provoke a biological response itself upon binding to a receptor, but blocks or dampens agonist-mediated responses...
s) to prevent complications in many of the victims. Assuming that carfentanil was the only active constituent (which has not been verified by the Russian military), the primary acute toxic effect to the theatre victims would have been opioid-induced apnea
Apnea
Apnea, apnoea, or apnœa is a term for suspension of external breathing. During apnea there is no movement of the muscles of respiration and the volume of the lungs initially remains unchanged...
; in this case mechanical ventilation
Mechanical ventilation
In medicine, mechanical ventilation is a method to mechanically assist or replace spontaneous breathing. This may involve a machine called a ventilator or the breathing may be assisted by a physician, respiratory therapist or other suitable person compressing a bag or set of bellows...
and/or treatment with opioid antagonists would have been life-saving for many or all victims.