Last updated : November 18, 2024
Heroin is an illegal drug in the United States that is ingested in a variety of forms, including intranasally (sniffed or snorted), intravenously, or inhalation (smoked). Regardless of the way it is taken, heroin has the same effect on the user’s body.
Heroin enters the bloodstream quickly and is converted by the body’s enzymes to morphine. Morphine is a powerful substance that acts on the brain to cause both the euphoria and the addictive behaviors associated with heroin. This morphine then binds to opioid receptors in the brain, brain stem, and body. Opioid receptors located in the brain control reward pathways, creating a sense of pleasure and also a need to use more of the drug. Opioid receptors in the body and brain are responsible for the pain relief associated with morphine, heroin, and other opiates. While these substances do no block pain pathways, they decrease perception of pain to dull it and make it more tolerable. The opioid receptors in the brain stem are responsible for the depressant effects of heroin, including lowered blood pressure and decreased respiration rate. The effects on the brain stem are primarily responsible for the disastrous effects of a heroin overdose, because users may stop breathing or experience dangerously low blood pressure.
When heroin is ingested regularly, the cells make fewer opioid receptors. This means that users develop a tolerance, in which they need increasing amounts of the drug in order to attain the same effect. In addition, other physiological changes happen that make it difficult for users to discontinue using the drug. Regular heroin users become very ill when they stop using the drug and usually require medical help to get through the period of withdrawal. Withdrawal is not just physically painful, but emotionally torturous as well. It can include nausea and vomiting a high heart rate, sweating, shaking, and a variety of unpleasant and potentially dangerous symptoms
Heroin is so quickly converted to morphine that users will experience the drug’s effects very rapidly. Intravenous users report feeling an immediate rush, with is both physically and psychologically pleasurable. Users who choose other methods of ingesting heroin will get the same effect but more slowly, over a few minutes. In addition, users will feel immediate changes in consciousness and mental functioning along with side effects such as a dry mouth and flushing of the skin. Once the initial reaction passes, heroin users feel alternating wakefulness and fatigue along with pain relief and emotional dulling.
These effects can have a negative impact on health when used once, but especially so when used regularly. Because heroin decreases respiration, users are more likely to develop lung conditions and infections. The reduction in blood pressure can cause infection of the heart and collapsed veins. Because of opiate effects on the organs, they may also experience cramping, constipation, liver damage, and kidney disease. Heroin is very dangerous to pregnant women and fetuses, even causing miscarriage at times. In addition, people who use heroin intravenously are at high risk for infection with diseases such as HIV and hepatitis in addition to abscesses. Heroin bought on the streets also has additives that can do permanent damage to blood vessels.
Heroin use is very dangerous, but modern medicine has a variety of ways to make it easier to stop using. There are drugs such as methadone that act on the same opioid receptors and decrease withdrawal. A drug called naloxone can be used to alleviate withdrawal as well. While there are several ways to support people who are trying to get clean, the best approach is to never try this dangerous drug.