Heroin is an opioid synthesized directly from the extracts of the opium poppy. The white crystalline form is commonly the hydrochloride salt diacetylmorphine hydrochloride. Upon crossing the blood-brain barrier, which occurs soon after introduction of the drug into the bloodstream, heroin mimics the action of endorphins, creating a sense of well-being; the characteristic euphoria has been aptly described as an "orgasm" centered in the gut. One of the most common methods of heroin use is via intravenous injection.
Due to heroin's mimicry of endorphins, it is used both as a pain-killer and a recreational drug. Frequent administration has a high potential for causing addiction and may quickly lead to tolerance, however occasional use may not lead to symptoms of withdrawal. If a continuous, sustained use of Heroin for as little as three days is stopped abruptly, withdrawal symptoms can appear. This is much shorter than other common painkillers such as oxycodone and hydrocodone.
Internationally, heroin is controlled under Schedules I and IV of the Single Convention on Narcotic Drugs. It is illegal to manufacture, possess, or sell heroin in the United States and the UK, however, under the name diamorphine, heroin is a legal prescription drug in the United Kingdom. Popular street names for heroin are gear, diesel, smack, B, skag, Harry, Bobby, black tar, horse, honk, munge, junk, brok, jack, jenny, blows, brown, brown sugar, brownstone, dark, sweaty, dope, pof, sam, waccocco, lovage, dragon, bitch, skurge, ron, ice cube, jim, moop, boy, sweet lady H and H.
Heroin is used as a recreational drug for its intense euphoria, which often disappears with increased tolerance. It is believed that heroin's popularity with recreational users, compared to morphine or other opiates, comes from its somewhat different perceived effects. This belief has not been supported by clinical research. In studies comparing the physiological and subjective effects of heroin and morphine administered intravenously in post-addicts, subjects showed no preference for one or the other of these drugs when administered on a single injection basis.
There was no difference found in their ability to produce feelings of "euphoria," ambition, nervousness, relaxation, drowsiness, or sleepiness. Data acquired during short-term addiction studies did not support the statement that tolerance develops more rapidly to heroin than to morphine. These findings have been discussed in relation to the physicochemical properties of heroin and morphine and the metabolism of heroin. When compared to other opioids -- hydromorphone, fentanyl, oxycodone, and meperidine, post-addicts showed a strong preference to heroin and morphine over the others, suggesting that heroin and morphine are more liable to abuse and addiction. Morphine and heroin were also much more likely to produce feelings of "euphoria", and other subjective effects when compared to most other opioid analgesics. Heroin can be administered in a number of ways, including snorting and injection. It may also be smoked by inhaling the vapors produced when heated (known as "chasing the dragon").
Some users mix heroin with cocaine in a so-called "speedball" or "snowball", which is usually injected intravenously although it can be smoked or dissolved in water and snorted. This causes a more intense rush than heroin alone but is more dangerous because the combination of the short-acting stimulant with the longer-acting depressant increases the risk of overdosing on one or both drugs.
Once in the brain, heroin is rapidly metabolized into morphine by removal of the acetyl groups, therefore, it is known as a prodrug. It is the morphine molecule that then binds with opioid receptors and produces the subjective effects of the heroin high.
The onset of heroin's effects is dependent on the method of administration. Taken orally, heroin is totally metabolized in vivo into morphine before crossing the blood-brain barrier; so the effects are the same as oral morphine. Snorting heroin results in an onset within 10 to 15 minutes. Smoking heroin results in an almost immediate, though mild effect which strengthens the longer it is used. Intravenous injection results in rush and euphoria within 7 to 8 seconds; while intramuscular injection takes longer, having an effect within 5 to 8 minutes.
Heroin, along with other opioids, are agonists to four endogenous neurotransmitters. The body responds to heroin in the brain by reducing (and sometimes stopping) production of the endogenous opioids when heroin is present. Endorphins are regularly released in the brain and nerves, attenuating pain. The reduced endorphin production in heroin users creates a dependence on the heroin, and the cessation of heroin results in extremely uncomfortable symptoms including pain (even in the absence of physical trauma). This set of symptoms is called withdrawal syndrome. It has an onset 6 to 8 hours after the last dose of heroin.
Large doses of heroin can be fatal. The drug can be used for suicide or, as in the case of Sigmund Freud, physician-assisted suicide. Heroin can also be used as a murder weapon. The serial killer Dr. Harold Shipman used it on his victims as did Dr. John Bodkin Adams. Dealers can also supply unwanted customers with unusually pure heroin, or heroin cut with other dangerous drugs such as fentanyl, resulting in a fatal overdose. It can sometimes be difficult to determine whether a heroin death was an accident, suicide or murder. The death of Joseph Krecker was such a case.
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