The opioid epidemic has gotten worse and worse over the past few years, partially due to the increase of fentanyl and its analogs in illicit trade. One of its analogs, carfentanil, is many times stronger than most of the opioids that are used in medicine and in illegal recreation. When people with opioid use disorders encounter these potent drugs, they can experience an overdose before they even realize what they were taking. What are these powerful substances, and how do fentanyl and carfentanil compare?
Fentanyl is a synthetic opioid that’s used to treat moderate to severe pain in hospital settings; it’s also become a common recreational drug in the past few years. As an opioid, fentanyl blocks pain signals from being sent and received all over the body. It works by binding to your brain’s opioid receptors. Opioid receptors are designed to bind with naturally occurring endorphins, which are responsible for regulating pain in your body. Opioid medications are very similar to your own endorphins, but they can be much more potent. For that reason, opioids, like fentanyl, are extremely effective at stopping pain and facilitating relief.
Unlike some other opioids, fentanyl is fast-acting. When taken intravenously, fentanyl starts working almost immediately. It reaches its peak effects within minutes. Because it works so quickly, it’s useful in treating labor pains, which can start quickly and unpredictably. If administered too late, slower-acting opioids may not be as effective. It’s also used in combat medicine. Military members that sustain injuries are often given fentanyl lozenges, in theater, to help manage severe pain until the injury can be treated medically.
Unfortunately, fentanyl has started to be used in the illegal opioid trade with more frequency in the past few years, and to detrimental results. Fentanyl and fentanyl analogs were involved in more than 28,000 drug overdose deaths in 2017.
Fentanyl is 80 to 100 times more powerful than morphine, according to the U.S. Drug Enforcement Administration. Because it’s so powerful, an effective dose is tiny and cheap. Fentanyl is cheaper than heroin and easier to transport in smaller packages, so dealers and black market drug traders are adding it to other drugs. Fentanyl has been found in heroin and cocaine, and it’s often mixed into drugs without users knowing.
Fentanyl improves the potency of drugs, even ones that have been diluted. However, it’s deadly in tiny amounts, as little as two to three milligrams. Untrained dealers often accidentally kill their customers by adding fentanyl.
Carfentanil is another synthetic opioid, and it’s also as fentanyl analog. Chemical analogs, also called structural analogs, are chemical compounds that are very similar in its structure to another compound. In many cases, analogs are created by slightly altering a drug, creating a unique substance.
Carfentanil is very similar in its structure, but the slight variation makes a big difference in at least one regard: potency. Carfentanyl is much stronger than fentanyl. In fact, the Centers for Disease Control and Prevention report that carfentanil is 10,000 times more powerful than morphine. That means even a tiny dose is enough to kill the average human. But carfentanil isn’t intended to be used by humans. The potent opioid is used as a tranquilizer for large animals, including elephants. However, its presence in illicit drugs has been increasing since around 2016.
Carfentanil is so potent that it has reportedly been used as a weapon in a hostage crisis in Moscow in 2002. Russian military used an aerosol mist containing carfentanil and remifentanil to subdue hostage-takers are the Dubrovka Theater in Moscow. More than 40 armed attackers and hundreds of hostages were exposed to the gas. Emergency services were unprepared to handle such a large exposure of potent opioids, and the incident resulted in the deaths of 125 people because of the gas and several more through other causes. The incident and carfentanil’s power has some concerned that it could be used as a chemical weapon.
Besides their obvious difference in potency, carfentanil and fentanyl have fairly similar effects in the body. They both bind to Mu-opioid receptors throughout the body and act as an opioid agonist, which means they activate their receptors. When these receptors are activated, they cause pain relief, relaxation, and euphoria. Both drugs can also cause similar adverse effects, including:
Both drugs begin to work quickly. If you take a deadly dose of either one, you are likely to experience respiratory depression quickly, leading to oxygen deprivation, brain damage, coma, or death.
Overdoses on both drugs can be treated with opioid antagonists like naloxone, that bind to opioid receptors and kick opioids off of those receptors. However, the drug needs to be administered quickly and in high enough doses to counteract these powerful substances.
They are both likely to cause some of the same withdrawal symptoms as other opioids.
Withdrawal from something like carfentanil isn’t typically seen because the drug is more likely to lead to death.
The biggest difference is the potency of carfentanil, which is deadly in much smaller amounts. The minimum lethal dose of carfentanil is unknown, but it’s estimated to be much smaller than fentanyl’s three milligrams. This level of potency makes it more dangerous in which to come into contact. Some reports say that fentanyl can be effective if it gets on your skin, but this is only true of transdermal patches, which are specially formulated to get through the skin. Encountering carfentanil may be more dangerous. Even trace amounts of powder that get into the air and inhaled may be deadly.
Opioids are notoriously addictive, and an opioid use disorder is difficult to get over on your own. Because of drugs like fentanyl and carfentanil, active opioid addiction is inherently dangerous, and each hit could lead to a fatal overdose.
If you or someone you know is struggling with an opioid use disorder, seeking help early can prevent some of the worst consequences of addiction. Substance use disorders are progressive and can get worse over time, spreading to other parts of your life. Before long, it could impact your health, relationships, finances, and even your legal standing. To take the first steps toward lasting recovery, learn more about opioid addiction and how it can be treated today.
Centers for Disease Control and Prevention. (2018, July 13). Notes from the Field: Overdose Deaths with Carfentanil and Other Fentanyl Analogs Detected – 10 States, July 2016–June 2017 | MMWR. from https://www.cdc.gov/mmwr/volumes/67/wr/mm6727a4.htm
DEA. (n.d.). Fentanyl. from https://www.dea.gov/factsheets/fentanyl
National Institute on Drug Abuse. (2019, January 29). Overdose Death Rates. from https://www.drugabuse.gov/related-topics/trends-statistics/overdose-death-rates
Nolan, M. L., Shamasunder, S., Colon-Berezin, C., Kunins, H. V., & Paone, D. (2019, February). Increased Presence of Fentanyl in Cocaine-Involved Fatal Overdoses: Implications for Prevention. from https://www.ncbi.nlm.nih.gov/pubmed/30635841
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