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The molecular structure of heroin
  • Heroin is the commonly used name for the drug diacetylmorphine (diamorphine). It is a semi-synthetic opiate drug, made by chemically altering morphine, which comes from opium poppies.

  • All heroin can cause serious harm, but many of the harms from the use of heroin depend on the type and quality, how the user gets it in into their body, and what else is getting in too. The way it is used also affects the chances of getting addicted.

    Illicit ‘heroin’ is typically less than 50% pure. The other constituents may include chemicals left over from the manufacturing process, chemicals added to enhance or mimic the effect (other opioids or sedative drugs), and stuff to bulk it up, like paracetamol. Heroin powder may also contain materials that give rise to infections, such as materials that contain spores of the bacteria that lead to anthrax or clostridium infections.

    With the variation in purity, the ‘strength’ of any given powder can be hard to know. At times this may lead to overdose when particularly high purity batches are sold on the illicit market.

    Brown heroin

    Brown powder heroin is the main type of heroin found in Europe. It is an off-white to brown powder or powdery clumps that consists of heroin ‘base’, plus various other potentially harmful substances (see below). Base heroin becomes a vapour when heated and it is often ‘smoked’ (‘chased’) from foil. It can also be snorted although this method of use is uncommon. Base heroin does not dissolve in water so to inject it users need to use an acid (like citric acid) to convert it into the ‘salt’ form.

    Heroin hydrochloride

    Unusual in Europe, this is the hydrochloride salt form. It dissolves in water and therefore easily prepares for injection. It can also be snorted, but is less suitable for smoking as it does not vapourise easily. Pharmaceutical heroin, diamorphine hydrochloride, is a white odourless powder.

    Black tar heroin

    Common in the USA, black tar heroin is rarely found in Europe. It is made using a cruder technique, which results in it consisting mainly of drugs that are part-way between heroin and morphine (3-MAM and 6- MAM). It resembles tar- being black or very dark brown, ranging from gooey to crumbly. It can be smoked and injected, though it is considered particularly damaging to inject.

  • Injecting- (usually into a vein, sometimes under skin or into muscle)

    As with the injection of any illicit drugs, injecting heroin poses the greatest risks. These include bacterial, fungal and viral infections, including abscesses at the site of injection, the collapse of veins, and infection with hepatitis HIV and other pathogens.

    Injecting, particularly intravenously, results in a strong and addictive rush of euphoria. If someone has regularly injected heroin into their veins, it tends to be very difficult to go back to using one of the less intense methods. Injecting heroin under the skin (subcutaneously) or into muscle (intramuscularly) is possible but gives a less of a ‘rush’. Subcutaneous and intramuscular injections pose a higher risk of bacterial infection at the site of infection.

    ‘Smoking’ (the drug is actually vaporised rather than burned to produce smoke)

    Compared to injecting, there is very much lower risk of overdose when smoking heroin- users have better control over their intake and can feel the effects of the drug very rapidly, regulating or stopping intake as necessary.

    Rectally- ‘plugging’ it (squirting it up the rectum with a syringe)

    Rectal use avoids injecting harms but has in common with injecting the fact that there is not much you can do if you use too much, which may be a seemingly small amount. Snorting avoids injecting harms, but most European heroin is not ideal for snorting.

  • Heroin is used recreationally because it produces intense feelings of euphoria and relaxation. Dependent individuals use it to ‘feel normal’ and avoid withdrawal symptoms. It works by affecting brain receptors involved in reward, pleasure and the perception of pain. The chemical modification of the morphine molecule to produce diamorphine has produced a drug that crosses the blood-brain barrier more quickly than morphine- this produces a rapid rise in brain levels of the drug and what users term a ‘rush’.

  • Heroin is a strong sedative and makes users feel peaceful, cosy and relaxed. Taken in a way that puts it into the bloodstream quickly (injecting mainly, but to a letter extent snorting, smoking, plugging), it will give a ‘rush’ of euphoric pleasure.

    Some people experience vomiting and nausea, especially the first few times they use heroin, which introduces a risk of death from choking on inhaled vomit. Heroin also causes significant constipation.

    Physical dependence will result after  regular, repeated use. Physical dependence means that the person using will experience withdrawal symptoms if they do not take heroin.

  • Diamorphine (pharmaceutical heroin) is used medically in many countries. Its primary use is for relief from severe pain. It is used for acute pain, (for example for heart attacks and accidents involving serious injuries) and chronic pain, for example that resulting from terminal cancer.

    In some European countries, people with heroin dependencies are given pharmaceutical heroin in specialist clinics where they can inject under supervision. This reduces the harms of using street heroin, and has been shown to prevent almost all overdose deaths, however it remains controversial.

  • Overdose

    Heroin and other opioids cause respiratory depression when used in overdose. This is when the drugs act on the brain and reduce the natural drive of the body to breathe.

    Additionally, people can die from becoming unconscious and choking on their vomit. These risks are made greater if heroin is taken with other drugs that cause sedation or make you vomit, such as alcohol.

    Overdoses can be caused either by accidentally taking too much, or by taking the same quantity of a purer batch of heroin, which amounts to the same thing. If heroin is injected, overdosing is much easier.

    Furthermore, many users have overdosed on an amount of heroin that they have taken many times before. This can happen because of a drop in tolerance. Tolerance  will reduce in a matter of days without heroin and its relatives, or only weak heroin, meaning a previously normal amount could cause overdose. Overdoses are very common when heroin users come out of prison due to little or no tolerance, or users bingeing on freely available drug supplies.

    Additionally some tolerance is dependent on the setting and routine in which a person normally takes heroin. Cues such as a particular room, handling injecting equipment or even a smell, will trigger changes in the body in preparation of the drug. This may explain some cases when heroin users have overdosed when taking the usual amount in a new or different environment.

    If an overdose is suspected immediate medical attention is required. Symptoms include slow, irregular or shallow breathing, pinpoint pupils, weak pulse, bluish lips and nails, muscle spasms.  A drug called naloxone is the emergency treatment for overdose. There are many urban legends for reviving someone in an overdose situation, but medical treatment with naloxone is the only appropriate course of action in the case of an overdose- failure can act appropriately can result in an avoidable death.

    Using illicit heroin long term, and the lifestyle that can accompany it are likely to lead to physical health problems.  Aging drug users have increasing vulnerability to overdose. Overdoses cannot always be seen as just a one-off accident.

  • The chance of your breathing and heart being dangerously affected by heroin will be increased if you have a heart or breathing condition, or low blood-pressure. Neurological or muscular conditions that could result in breathing being weakened might also increase risks.

    Some people are allergic to opiates like heroin, and others can suffer serious allergic reactions to various substances that heroin has been cut with. Life-threatening asthma attacks have been caused by smoking or snorting heroin.

    Injecting heroin can spread diseases and also makes wounds that often become infected. Any condition that lowers the immune system will increase the risks.

  • Many overdoses and fatalities result from the combination of heroin with other drugs. Other sedatives such as alcohol, benzodiazepines (e.g. diazepam- ‘Valium’, and temazepam) and other opiates (e.g. methadone) are frequently involved in accidental overdoses.

    Combining heroin with a stimulant could also raise the risk of harm or death, although the evidence is not fully clear. The combination of heroin and cocaine, often called a ‘snowball’ or ‘speedball’, is a well-known example. This seems to be linked to a greater chance of overdose , although there is some evidence that it simultaneously may decrease the chance of that overdose being fatal.

  • Heroin can be very addictive. There are various aspects to heroin addiction. Firstly people may keep taking the drug because it is very pleasurable. After taking the drug repeatedly tolerance may then develop. Part of the way the brain and body develops tolerance is by producing the opposite effect of the drug, which means that a tolerant person will need the drug to stay at normal levels. Without the drug the person will experience withdrawal effects. Withdrawal effects are in some ways opposite to the effect of the drug. For example, heroin causes constipation, so a person can experience quite extreme diarrhoea in withdrawal.

    Many people who become addicted to heroin suffered trauma and/or problems with mental health in their early life, before using heroin. This suggests that some people use it despite the risks as a form of self-medication, which is likely to lead to dependence.

  • Withdrawal symptoms include: sweating, depression, stomach cramps, diarrhoea, feelings of discomfort and unease, nausea and vomiting, and craving for heroin. Heroin withdrawal is very unpleasant which is a major reason why people addicted to heroin continue to use despite experiencing more and more harms, and less pleasure from use as time goes on.

    Heroin’s illegality, its addictiveness and its disruptive influence on employment means that some users can be drawn into making money in ways they otherwise wouldn’t, such as stealing or prostitution, to maintain a heroin addiction. Many heroin dealers are users who sell drugs to fund their own habit. The needs of dependents, such as children of heroin addicts, are often compromised by the time and money needed to  maintain a heroin addiction.

    There is also still a significant social stigma over heroin use. People who are dependent on  or have previously been dependent upon heroin may find it hard to be trusted and  employers may discriminate against them.

  • Injecting heroin carries the risk of infection from viruses or bacteria, especially if people are sharing needles. Repeated injections cause veins to become scarred and collapse.

    The harms of heroin are linked to the harms of poverty and unstable lifestyle. Many problems may be caused by neglecting other things necessary for wellbeing in order to maintain the habit.

  • Street heroin is a drug which always has a high potential for causing harm. However, there is enormous variability in the risks suffered by different users with different habits. When the costs of use can be so high, there is an especially strong reason to make every effort to minimise harms.

    Avoiding use, minimising use, avoiding addiction.

    Whilst the body does not immediately develop a physical dependency, people will often like the drug and want to repeat the experience from the first use. If you encounter heroin regularly in your social or family life, this constant availability will add to the temptation to repeat an initial experience, as will stresses in life.

    If you do use heroin occasionally and do not wish to stop despite the risks, it is important to be vigilant and reactive to signs of dependence. Growing tolerance for heroin (needing more to feel the same effects) is an important warning sign of some of the changes in your brain chemistry that lead to cravings and withdrawal effects when you don’t use.

    How are you taking it?

    Injecting heroin carries with it more risks than smoking or snorting heroin. Firstly, with heroin injection the total dose is taken in one go, so it is easy to overdose. Judging the amount to use is made more difficult because heroin purity varies. It is therefore much better to take a small amount to see how strong it is before taking a moderate dose. As injecting heroin produces such a big rush it is easier to become addicted to heroin when injecting.

    If a user is injecting, they can still do many things to reduce unnecessary harms. Deliberately, or accidentally sharing used needles carry the risk of infection from viruses such as HIV and hepatitis. Using new sterile equipment reduces the risk of  infection. Using lemon juice or vinegar as acids to make brown base heroin is very risky – lemon juice is linked to fungal infections including inside the eyeball. In many countries, advice on safer injection and free equipment can be accessed at needle exchanges.

    Are you having anything else? Mixing other drugs with drink can be very risky

    Taking heroin with any other drug that can stop breathing (e.g. alcohol or benzodiazepines) increases the risk of overdose.

    Additionally, taking heroin with stimulants like cocaine and speed (amphetamine) can suppress some of their negative side effects . This is a problem as the effects of cocaine or speed will wear off before heroin does meaning a person could take both drugs and then overdose when the stimulant wears off. Doing this may also be more addictive.

  • Can heroin dependence happen from one use?

    It takes repeated uses over a short space of time to become physically addicted to heroin, so that symptoms appear when you don’t take it. However, heroin is, at least to some people, immediately satisfying and pleasurable (even if it causes vomiting), and some dependent users feel that they ‘fell in love’ with the drug from the first try. Heroin can give a deep feeling of relief and comfort, and having had it once, any time when an individual feels in need of relief and comfort, the temptation to use it may arise.

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