Heroin (chemical name diacetylmorphine) is an organic chemical substance and an opioid analgesic. Heroin is made by the processing of morphine, which is another opioid that naturally comes from the opium poppy plant. In modern times, heroin has been used by humans as an analgesic and a recreational drug.
Heroin crosses the blood-brain barrier faster than does morphine base, which makes it addictive because the "rush" of onset is faster and more intense. Along with cocaine and methamphetamine, heroin is often colloquially categorized as a "hard drug", as opposed to "soft drugs" such as marijuana, which is considerably less addictive and harmful. Victims of heroin overdose include celebrities such as Janis Joplin and Bridgette Andersen.
Governments around the world mostly have enacted strict laws against the production, distribution, and possession of heroin. In the United States, it is listed as a Schedule I drug by the Controlled Substance Act, which means it has high potential of abuse and even medical use is disallowed. Street names for heroin include "junk", "dope", and "smack". Heroin addicts are often informally referred to as "junkies".
In 1874, a British researcher named C. R. Wright discovered the substance by boiling morphine and acetic anhydride. It had similar effect to morphine and was thought to be non-addictive. Subsequently, the Bayer Pharmaceutical company began massively producing it under the name of "heroin". However, it was proved to be even more harmful than morphine and from 1923 the U.S. and other governments started to outlaw heroin.
Heroin is a prodrug, which must be biotransformed into a biologically active substance (morphine) before it takes effect. This biotransformation occurs both within the brain, and throughout the body. Heroin is very lipid soluble and easily cross the blood-brain barrier. As a comparison, 68% of intravenous heroin enters the brain while only 5% of intravenous morphine does the same.
Outside the brain, that is, within the peripheral nervous system, heroin is hydrolyzed by the protein carboxylesterase 1 (hCE1) into 6-acetylmorphine, then into morphine.
- From 1971 heroin use only as illegal drug.
- Oldendorf WH, Hyman S, Braun L, Oldendorf SZ (1972). "Blood-brain barrier: penetration of morphine, codeine, heroin, and methadone after carotid injection". Science 178 (64): 984–6. PMID 5084666.
- Bencharit S, Morton CL, Xue Y, Potter PM, Redinbo MR (2003). "Structural basis of heroin and cocaine metabolism by a promiscuous human drug-processing enzyme". Nat. Struct. Biol. 10 (5): 349–56. PMID 12679808.