Carfentanil or carfentanyl is an analog of the synthetic opioid analgesic fentanyl. A unit of carfentanil is 100 times as potent as the same amount of fentanyl, 5,000 times as potent as a unit of heroin and 10,000 times as potent as a unit of morphine.
The toxicity of carfentanil in humans and its ready commercial availability has aroused concerns over its potential use as a weapon of mass destruction by rogue nations and terrorist groups.
Carfentanil was first synthesized in 1974 by a team of chemists at Janssen Pharmaceutica which included Paul Janssen. It is classified as Schedule II under the Controlled Substances Act in the United States with a DEA ACSCN of 9743 and a 2016 annual aggregate manufacturing quota of 19 grams (less than 0.7 oz.)
CARFENTANIL AND OPIOID ADDICTION
Unlike other morphine derivatives, heroin, or other opioid narcotics, carfentanil does not lead to addiction. It is too powerful for humans who have not developed a tolerance to strong narcotics like heroin or fentanyl. Even for people who have struggled with addiction to powerful narcotics, a dose the size of a grain of salt can rapidly lead to an overdose and death.
However, carfentanil has been found cutting heroin and even fentanyl sold on the streets, starting in July 2016 in Ohio, when 35 overdoses and six deaths occurred in a span of three days. Law enforcement and emergency medical personnel warn that carfentanil sold illicitly looks like other drugs found on the street, including cocaine and heroin, because it is an odorless, white powder. Carfentanil, like fentanyl, has been found cutting heroin in order to increase its potency and the heroin dealer’s supply of the substance.
While adding fentanyl to heroin has led to an epidemic of overdoses, carfentanil has led to deadly overdoses much faster. For comparison, according to Elephant Care International, the dose of carfentanil safely administered to sedate a wild adult male African elephant, which can weight over 1 ton, is only 13 mg. A dose of fentanyl, 100 times less powerful than carfentanil, that can safely be administered to a human adult is up to 100 micrograms per hour – the equivalent of 0.1 mg. The dose for the elephant is equivalent to 13,000 micrograms of carfentanil, which is about 1.3 million micrograms of fentanyl. Hence, 1,000 mg of fentanyl, the equivalent in potency of 1 mg of carfentanil, will easily kill a human.
According to an article from the Washington Post, carfentanil’s deadliness can be expressed in a few ways. First, the Buffalo Field Campaign based out of Yellowstone National Park warns that humans should not eat the meat of bison who have been sedated with carfentanyl, because it can enter the human’s body and cause an overdose. Second, Russian authorities used a weaponized chemical gas based on carfentanil to end a Chechen hostage crisis in 2002 and ended up killing 170 people with one dose.
The dose used to cut heroin is typically so small that forensic chemists often have a hard time finding it. Even so, that small amount is enough to send a person into an overdose. The Ohio Attorney General website recommends that forensic technicians and chemists who must field-test heroin for fentanyl or carfentanil use protective gear to avoid harming or killing themselves.
HOW DOES CARFENTANIL AFFECT HUMANS?
Because of carfentanyl’s potency, the effects on the human body and brain are very rapid. Even in elephants, the sedative effects are especially rapid. According to Elephant Care International, veterinarians must watch elephants for signs of pulmonary edema and capillary bleeding, characterized by a pink foam issuing from the elephant’s trunk, which indicates a potentially fatal rise in blood pressure. While doses administered to elephants are specifically to knock the animal unconscious, the doses are small compared to doses of much less powerful narcotics, like oxycodone or hydrocodone, given to humans to treat pain. When even a fraction of the dose given to elephants is administered to humans, onset is rapid, difficult to stop, and hard to treat.
Effects on the Brain
Carfentanil rapidly binds to opioid receptors in the brain, overwhelming neural chemistry and leading to overdose symptoms almost immediately. Fentanyl, for comparison, creates an intense euphoria and drowsiness when binding to the opioid receptors in the brain. These sensations are caused by elevated dopamine levels and a reduced ability for the opioid receptors to absorb this neurotransmitter due to the presence of the narcotic. These receptors also control breathing rate, which is why opioid overdoses are typically characterized by depressed, irregular, or stopped breathing.