Drug misuse

Page last reviewed: 13/07/2011

A drug is a chemical substance that acts on the brain and nervous system, changing a person's mood, emotion or state of consciousness.

Drugs are often classified by the effect they have.

  • Stimulants, such as cocaine, make people feel full of energy.
  • Depressants (or sedatives), such as heroin, make people feel relaxed.
  • Hallucinogens, such as LSD, make people see, feel or hear things that are not real.

Drug misuse is when a person regularly takes one or more drugs to change their mood, emotion or state of consciousness.


One of the biggest risks of drug misuse is that you can develop a drug addiction. There are two main types of drug addiction:

  • Physical addiction, when there are withdrawal symptoms, such as nausea, vomiting or cramping, if the supply of the drug is suddenly withdrawn.
  • Psychological addiction, when there is a psychological compulsion or need to regularly use a drug. If the drug is withdrawn, there are no physical symptoms but there may be psychological symptoms such as depression, anxiety and irritability.

Legal drugs

Under Irish law, most drugs are illegal. However, some drugs are legal, including:

  • caffeine
  • alcohol
  • cigarettes

If a drug is legal, that does not mean it is harmless. In Ireland each year, cigarettes and alcohol kill more people than all illegal drugs put together.

Prescription medication, such as strong painkillers or tranquillisers, is often misused by people who have no clinical need for it but use it for its mood-altering effects.

In many cases, it is illegal to posses certain types of prescription medication, such as morphine or methadone, without a valid prescription.

Risks to health

As well as the danger of addiction, drug misuse has serious health risks and is associated with a wide range of conditions and complications, both physical and psychological.For example, cocaine can cause heart failure and heroin can cause respiratory failure (loss of normal lung function), both of which can be fatal.

If a person uses a needle to inject drugs, they have a high risk of catching a serious blood-borne infection, such as HIV or hepatitis C.

Dependence is a compulsion to continue taking a drug in order to feel good or to avoid feeling bad.
Painkillers, or analgesics, are medicines that relieve pain. Examples include paracetamol, aspirin and ibuprofen.
Steroids are types of chemicals found naturally in the body. They are also produced artificially to treat diseases.
Benzodiazepines are a group of medicines used to help sleep, reduce anxiety and as a muscle relaxant. Examples include temazepam.
Pain is an unpleasant physical or emotional feeling and your body's way of warning you that it has been damaged.

Useful Links

If you have suffered an injury (needle stick or other sharps injury, sexual exposure, human bites, exposure of broken skin or of mucous membranes) where there is a risk of transmission of blood borne viruses and other infections, further information on how to manage your situation is at: www.emitoolkit.ie

Page last reviewed: 13/07/2011


The most commonly misused illegal drugs in Ireland are outlined below.


Cannabis comes from a plant that is found in most parts of the world. It comes in two forms:

  • Herbal cannabis (often known as weed or grass) is made up of the dried leaves and buds of the cannabis plant.
  • Cannabis resin (often known as gear or hash) is a brown or black lump of resin that is taken from the cannabis plant.

Cannabis is usually smoked, either mixed with tobacco in a hand-rolled cigarette (joint) or by itself in a pipe.

Using cannabis can make you feel relaxed and happy and many users feel that they have a heightened sense of awareness. Adverse reactions associated with cannabis use include:

  • paranoia, and
  • anxiety.


Amphetamines are a group of synthetic (artificial) drugs that are powerful stimulants. They are often known as speed, billy or wizz.

Amphetamines usually come as a powder, which can be snorted through the nose, rubbed into the gums or wrapped in a cigarette paper and swallowed (speedbomb).

Some amphetamines are available in tablet form. There is also a very strong smokeable form of amphetamine known as crystal meth. Amphetamines can be injected.

Shortly after taking amphetamines, you will experience a rush (a sudden energy boost) and feel very energetic, talkative and excited. This rush, or high, will usually last between four and eight hours, depending on the amount of amphetamines taken.

Once the effects of the amphetamines have worn off, you will experience what is known as a crash, or comedown, and will feel:

  • very tired but unable to sleep,
  • anxious,
  • irritable, and
  • depressed.

These effects can last for several days.


Cocaine is a stimulant that is extracted from the coca plant. It is often known as coke or charlie.

Cocaine comes in powder form and can be snorted or rubbed into the gums. There is a form of smokable cocaine that is often called crack. Crack is also known as rocks or base.

People who take cocaine will experience an intense feeling of wellbeing, self-confidence and energy. These feelings may only last for 20 to 30 minutes, which often leads people to take more cocaine.

The effects of crack are more intense than cocaine, but they do not last as long. Typically, a crack high will only last for 10 minutes.

Once a person has used up their supply of cocaine or crack, their high will soon end and they may feel very depressed, tired and paranoid.

Both cocaine and crack are class A drugs.


Ecstasy is a class A drug. It is a synthetic (artificial) stimulant that is popular among clubbers. The chemical name is methylenedioxymethamphetamine (MDMA). Ecstasy is often known as pills or E.

Ecstasy usually comes as a tablet. Less commonly, a powdered form of MDMA used.

People who take ecstasy often experience a rush of energy that makes them feel alert, excited and happy. Sound, particularly music, and colours seem more intense and many people feel an increased sense of affection for people around them.

The ecstasy high usually lasts three to six hours, after which it is replaced by a comedown similar to that experienced after taking cocaine or amphetamines.


In Ireland, the two most commonly used hallucinogens are:

  • magic mushrooms, and
  • lysergic acid diethylamide (LSD).

Magic mushrooms grow in the wild and have hallucinogenic properties. They are sometimes known as shrooms or mushies.

Magic mushrooms can either be eaten or boiled in liquid, which is then drunk.

LSD is a synthetic (artificial) liquid that is usually dropped on to small squares of blotting paper, which are then swallowed. LSD is often known as acid.

The effects of magic mushrooms and LSD are similar, but LSD tends to cause more intense, longer-lasting effects.

People who take magic mushrooms or LSD will experience a long-lasting series of hallucinations, known as a trip.

During a trip, sounds and colours can become distorted, emotions can become heightened and time can appear to both speed up and slow down.

A magic mushroom trip tends to last between four and 10 hours. An LSD trip lasts for about 12 hours.

Some people who take hallucinogens experience frightening and disturbing hallucinations. This is known as a bad trip. Bad trips can be intensely unpleasant.

Both magic mushrooms and LSD are class A drugs.


Tranquillisers are a prescription medication designed to treat anxiety, depression and insomnia.

Many people misuse tranquillisers to lessen the effects of a comedown after taking stimulants as they can have a calming and sedating effect. Alternatively, some people may use them to ease drug withdrawal symptoms.

Tranquillisers come as tablets, gel capsules, in injection form and as suppositories (tablets that you insert into the anus).

Tranquillisers are often known as mazzies, benzos or jellies.

It is possible to accidentally overdose on tranquillisers, particularly if they are taken with alcohol.


Solvents are household chemicals. Some people, particularly teenagers, abuse them by sniffing the fumes they give off.

There are over 200 different types of solvent. Some common household solvents include:

  • glue,
  • hairspray,
  • lighter re-fillers,
  • paint,
  • deodorants, and
  • cleaning fluids.

When inhaled, solvents have an effect that is similar to being drunk, such as feeling giddy, uninhibited and giggly.

Solvent abuse is potentially very dangerous because it can cause heart failure.

Although solvents are not illegal, it is illegal to sell certain solvent products to people under 18.


Ketamine is a class C drug and a powerful synthetic anaesthetic. It comes in a powdered form that can be snorted or as a liquid that can be injected. It is often known as special K or vitamin K.

People who use ketamine experience LSD-like hallucinations and often report feeling that their mind is floating outside their body.

Ketamine abuse has been linked to an increased risk of depression, panic attacks and bladder problems, such as having to pass urine every 15 minutes.


Heroin is a powerful painkiller and sedative that is derived from the opium poppy. Drugs, such as heroin and codeine, that are derived from the opium poppy are called opiates.

Heroin comes as a powder and can be smoked or dissolved in water and injected. It is often known as brown, smack or skag.

People who use heroin experience an intense feeling of relaxation and wellbeing. Heroin is highly addictive, both physically and psychologically.

Heroin carries a high risk of overdose. This is because the purity of heroin can vary dramatically between different batches of the drug, so people often take a stronger dose of heroin than their body can cope with.

Useful Links



If you have suffered an injury (needle stick or other sharps injury, sexual exposure, human bites, exposure of broken skin or of mucous membranes) where there is a risk of transmission of blood borne viruses and other infections, further information on how to manage your situation is at: www.emitoolkit.ie

Page last reviewed: 13/07/2011

Drug misuse can be dangerous for three main reasons:

  • you could become addicted to the drug,
  • the drug could cause physical and psychological harm, and
  • drug abuse can have a negative effect on your quality of life.


How addictive a drug is likely to be is determined by two things:

  • how pleasurable taking the drug is, and
  • how quickly the drug reaches your brain.

Drugs that are smoked, injected or snorted can reach the brain very quickly and are usually more addictive than drugs that are swallowed.

In 2007, the medical journal The Lancet commissioned a number of drug experts to asses how potentially addictive the most popular illegal drugs are. The results, in order of addictiveness with the most addictive at the top, were:

  • Heroin.
  • Cocaine.
  • Tranquillisers.
  • Amphetamines.
  • Ketamine.
  • Cannabis.
  • Hallucinogens.
  • Ecstasy.

Physical and psychological harm


The short-term effects of cannabis include:

  • dizziness and sickness,
  • dry mouth, lips and tongue,
  • panic and paranoia (when you are suspicious of people and situations),
  • feeling hungry, and
  • loss of co-ordination.

Long-term effects of regular cannabis use include:

  • lung disease and lung cancer,
  • respiratory problems, such as bronchitis and asthma,
  • high blood pressure (hypertension), and
  • infertility.

There is some evidence that long-term cannabis use can increase your risk of mental health conditions, such as depression and schizophrenia.


Amphetamine use can lead to:

  • short-term dizziness,
  • hallucinations,
  • burst blood vessels that, in very rare cases, can lead to paralysis (muscle weakness) and may be fatal,
  • insomnia, and
  • depression.

As your body becomes more tolerant to the drug, larger amounts are needed to get the same effect. This increases both the risks to your health and the chance of becoming addicted.

Cocaine and crack

Cocaine raises blood pressure, causes the heart to beat irregularly and increases body temperature. As well as causing heart failure when taken in large doses, the long-term use of cocaine can lead to:

  • depression,
  • insomnia,
  • extreme paranoia,
  • extreme weight loss and malnutrition,
  • impotence in men, and
  • serious damage to the nasal passages.

Because cocaine is so addictive, users experience withdrawal symptoms, such as intense irritability and restlessness, if they go for longer than usual without taking it. This period of time becomes shorter and shorter as the body becomes more tolerant to the drug, and larger quantities are required to experience a high. As the effects of the drug wear off, users will get symptoms such as exhaustion and depression.

Women who use cocaine while pregnant put the health of their baby at risk because the drug can cause low birth weight and birth defects. Their baby may also be born addicted to cocaine.


Very few ecstasy tablets are pure ecstasy. Most contain other substances, such as talcum powder. Some ecstasy tablets have even been found to contain dog-worming medicine. More dangerous substances, including anaesthetics and tranquillisers (such as ketamine), may also be added to ecstasy tablets.
Dehydration is a major risk when taking ecstasy. Ecstasy raises your body's temperature and the amphetamine contained in each tablet encourages you to behave energetically for long periods of time, for example by dancing in a club all night.

If your fluid levels drop dramatically, dehydration can cause unconsciousness, coma and even death. If you take large amounts of ecstasy, you may experience feelings of anxiety, panic and confusion and it can be difficult for other people to calm you down. Other unpleasant side effects include:

  • dry mouth,
  • nausea,
  • raised blood pressure, and
  • depression.

Some users say that their body stiffens after taking ecstasy, often causing them to clench their jaw and grind their teeth. Another common symptom is an increased heart rate, which can feel like your heart is pounding or hammering in your chest.

The use of ecstasy became widespread during the late 1980s, so it is too early to know whether regular users, or those who used to use the drug regularly, will experience long-term side effects.


Many tranquillisers are addictive if they are used regularly. Tranquillisers are physically addictive, so you may have withdrawal symptoms if your supply is stopped suddenly.

Withdrawal symptoms can include:

  • severe headache,
  • nausea,
  • anxiety, and
  • confusion.

Some people who abuse tranquillisers try to inject crushed-up tablets or melted-down gel capsules to increase the potency of the drug.

This can be very dangerous because the chalk contained in many tablets can cause veins to collapse. This can lead to serious infections and, in the most extreme cases, the death of tissue (gangrene). Gel capsules that are melted down can sometimes solidify inside blood vessels, which can be fatal.


Many solvents contain chemicals that have a toxic effect on the body, particularly the heart.

Every time you sniff a solvent, you are at risk of having a heart attack, which may be fatal Other adverse effects of solvent abuse include:

  • vomiting,
  • blackouts, and 
  • in the case of long-term abuse, liver, kidney and brain damage.


Ketamine is a powerful anaesthetic. It is possible to badly injure yourself during a ketamine high without realising it as you will not feel any pain.

Mixing ketamine with stimulants, such as ecstasy or amphetamine, can cause a dangerous rise in your blood pressure.

High doses of ketamine can suppress your normal brain and breathing functions and can cause you to become unconscious. Once unconscious, there is a risk that you will choke on your own vomit.

There is an increasing amount of evidence that long-term ketamine misuse can cause serious damage to your kidneys and bladder. This can lead to a range of unpleasant symptoms, such as:

  • a frequent urge to urinate,
  • pain when urinating,
  • urinary incontinence, and
  • blood in your urine.


Hallucinogens are very unpredictable and it is possible to have a 'bad trip' even if all your previous trips have been enjoyable. A bad trip can feel like being trapped in a nightmare.

There is a risk that somebody may act irrationality or impulsively during a trip and place themselves in physical danger, for example by suddenly running into a busy road.

While hallucinogens are not thought to cause mental heath problems, they could make an existing mental health condition more severe.

With magic mushrooms, there is a risk that you or your supplier may mistake poisonous mushrooms for magic mushrooms. Mushroom poisoning can be very serious and is often fatal.


Most heroin that is bought on the street is only 10-60% pure. It is usually mixed with other substances to increase the quantity and to make it more profitable. It is often the substances that are used to bulk up heroin that are the most harmful, causing allergic or toxic reactions. Users can never be sure that the heroin they buy has not been mixed with dangerous substances.

Because it is impossible to know how pure heroin is, it is easy for the user to take an overdose. Overdosing on heroin can cause heart failure, unconsciousness and coma. There is also a risk that the user will choke on their own vomit if they are sick while unconscious.

Injecting heroin has additional risks. Sharing needles increases the risk of contracting serious diseases, such as hepatitis C and HIV. Long-term injecting may cause damage to veins, serious infections, such as abscesses (pus-filled swellings), and severe constipation.

The wider impact of drug misuse

As well as the impact on your health, drug misuse can have a negative effect on your quality of life and relationships with others.

Many drug abusers find that they lose touch with their family and friends or that their family and friends lose patience with them due to their unreasonable behaviour.

Hobbies, interests and ambitions can be forgotten as drugs become more and more important. It can become increasingly difficult to hold down a job if you have a drug problem.

People with a serious drug addiction, such as a heroin, cocaine or crack addiction, often resort to desperate, illegal and dangerous activities to find money to pay for their drugs. Examples include:

  • begging,
  • burglary,
  • shop-lifting,
  • street crime, such as mugging or bag snatching, and
  • prostitution.

Useful Links


If you have suffered an injury (needle stick or other sharps injury, sexual exposure, human bites, exposure of broken skin or of mucous membranes) where there is a risk of transmission of blood borne viruses and other infections, further information on how to manage your situation is at: www.emitoolkit.ie

Page last reviewed: 13/07/2011

Getting help in an emergency

If a drug user is showing unusual symptoms or seems to be in distress, they may have had an allergic reaction to a drug or they may have overdosed. Symptoms to look out for include:

  • dizziness,
  • sickness or nausea,
  • sudden tiredness,
  • headaches,
  • muscle cramps and aches,
  • irregular breathing,
  • heavy slurring of speech,
  • convulsions, and
  • paralysis (muscle weakness).

If you think someone is having a reaction to a drug or has overdosed, take the following actions:

  • Call 999 and ask for an ambulance. Speak clearly and calmly. Tell the operator exactly where the person is, what drugs they have taken and what symptoms they have. Listen carefully to any advice given by the operator. You may need to give mouth-to-mouth resuscitation, put the person into the recovery position or give other forms of life-saving treatment. You will need to stay calm and keep a clear head.
  • Make sure the person's airways are not obstructed. Look out for vomit blocking the airway and check that the person has not swallowed their tongue.
  • Collect evidence of any drugs that have been taken. This is vital to help doctors make a quick diagnosis and provide the best possible treatment. Collect containers that drugs have been kept in, including wrappers, packets, cling film, tin foil and syringes. If the person has been sick, try to collect a small sample of vomit for analysis at the hospital.

Helping yourself

The first and most difficult step for people who misuse drugs is to recognise that they have a problem, and then admit that they need help to deal with it.

Some people realise that they have a problem but find it hard to stop taking the drug, even though they are aware of the consequences. Others may need someone else to help them realise that they have a problem.

Signs that a person may have a drug problem or addiction include:

  • continually increasing the dose of drugs to get the same effect,
  • a feeling of dependency on drugs or a fear of stopping using drugs,
  • withdrawal symptoms if they stop taking the drug for a short time,
  • sudden mood changes,
  • a negative or changed outlook on life,
  • a loss of motivation,
  • poor performance at work or college,
  • problems with personal relationships,
  • borrowing or stealing money from friends and family, and
  • being secretive about activities and actions.

Next steps

See your GP as soon as you recognise you have a drug problem. They can give you advice and support and refer you for specialist treatment. Be honest with your GP about your drug use and your reasons for wanting to give it up. You may also want to tell close family and friends about your decision and ask them for their support.

For details of services and support go to http://www.drugs.ie/


Dose is a measured quantity of a medicine to be taken at any one time.
Nausea is when you feel like you are going to be sick.
Vomiting is when you bring up the contents of your stomach through your mouth.
An allergen is a substance that reacts with the body's immune system and causes an allergic reaction.
An ache is a constant dull pain in a part of the body.

Useful Links


If you have suffered an injury (needle stick or other sharps injury, sexual exposure, human bites, exposure of broken skin or of mucous membranes) where there is a risk of transmission of blood borne viruses and other infections, further information on how to manage your situation is at: www.emitoolkit.ie

Page last reviewed: 13/07/2011

There are two types of treatment for drug misuse:

  • pharmacological treatment, where medication is used to ease drug withdrawal symptoms, and
  • psychological treatment, where a range of different therapies are used to help you stay off drugs.

Pharmacological treatments

Pharmacological treatments are only available for people with a heroin or tranquilliser addiction. There are currently no pharmacological treatments for other types of drug.


If you have a heroin addiction, there are two different medications that can ease your withdrawal symptoms. These are:

  • methadone, and
  • buprenorphine.

Both medications are synthetic (artificial) opiates that replicate some of the effects of heroin on the brain. The brain is 'tricked' into thinking that it is receiving a dose of heroin, so you do not have withdrawal symptoms.

Methadone and buprenorphine can be used in two ways:

  • withdrawal therapy, where the doses of medication are gradually reduced over time before the treatment is withdrawn, and
  • maintenance therapy, where you receive regular doses of medication on a long-term basis.

Many people choose to have maintenance therapy for several months so that their health and general wellbeing can improve. Once they are physically and psychologically stronger, they choose to withdraw from the treatment.

Because there is a possibility that a person may not use the medication as directed (for example, by selling their methadone to others), you may have to take the medication under supervision. You may also be required to have regular urine tests to check that you are not taking heroin.


Naltrexone is a medication that can be used when you have not taken heroin for several weeks but are worried that you may relapse and take heroin again.

Naltrexone blocks the effects of heroin on your brain, so even if you take heroin you will not experience a high.


Depending on how addicted you are, you may be prescribed a course of tranquillisers to ease your withdrawal symptoms. The dose will gradually be reduced over time until treatment is withdrawn.

Psychological treatments

Self-help groups

Many people who have a drug misuse problem join a self-help group, such as Narcotics Anonymous.

Most of these groups are based on a 12-step programme to overcome addiction (created by Alcoholics Anonymous), which includes the following points:

  • You admit that you are unable to control your addiction or compulsion.
  • You recognise that you need a power greater than yourself to restore your strength.
  • You examine past errors in your life with the help of a sponsor (an experienced member of the group).
  • You make amends for those errors.
  • You learn to live a new life with a new code of behaviour.
  • You help others who have the same addiction or compulsion.


Anxiety is an unpleasant feeling when you feel worried, uneasy or distressed about something that may or may not be about to happen.
A fever is when you have a high body temperature (over 38°C or 100.4°F).
Vomiting is when you bring up the contents of your stomach through your mouth.
Nausea is when you feel like you are going to be sick.
An ache is a constant dull pain in a part of the body.
Depression is when you have feelings of extreme sadness, despair or inadequacy that last for a long time.

Useful Links


If you have suffered an injury (needle stick or other sharps injury, sexual exposure, human bites, exposure of broken skin or of mucous membranes) where there is a risk of transmission of blood borne viruses and other infections, further information on how to manage your situation is at: www.emitoolkit.ie

Content provided by NHS Choices www.nhs.uk and adapted for Ireland by the Health A-Z.

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