Medicines for Drug Dependence

Dependence on a drug means that you need that particular drug to function normally. It is sometimes referred to as drug addiction or dependency. Some drugs that cause dependence include nicotine, morphine, heroin (also know as diamorphine), cocaine, amfetamine, and alcohol. In addition some people can become dependent upon medicines that are prescribed or bought from their local pharmacy. There are a number of medicines that your doctor may prescribe to help with drug dependency. The type of medicine prescribed depends on the drug you are dependent on.

What is drug dependence?

Dependence on a drug means that you need that particular drug to function normally. It is sometimes referred to as drug addiction or dependency. People who have drug dependence may have psychological dependence, physical dependence or tolerance to a particular drug.

Psychological dependence means that you have a craving or are compelled to use a particular drug to give you pleasure or to stop you from feeling bad. Even though it may be dangerous to take the drug.

Physical dependence means that if the drug is stopped suddenly you get withdrawal symptoms. For example, if you are dependent on heroin and stop this drug suddenly then you may get the following symptoms: sweating, feeling hot and cold, runny eyes and nose, yawning, being off food, stomach cramps, feeling sick or vomiting, diarrhoea, tremor, poor sleep, restlessness, general aches and pains, and just feeling awful.

Tolerance is usually a part of dependence, it means that you need more and more of the same drug to give you the same feeling as the smaller amount you used when you first starting taking that drug.

Examples of some drugs that cause dependence include nicotine, morphine, heroin (also know as diamorphine), cocaine, amfetamine, and alcohol. Some people can also become dependent on medicines that are on prescription, such as benzodiazepines or Z drugs (for example, lorazepam, diazepam, or zopiclone) and codeine, as well other medicines that can be bought from pharmacies - for example, over-the-counter painkillers. (Z drugs are called this because they begin with the letter Z.)

This leaflet gives a brief overview of the medicines that are used to treat dependence on opiates (such as heroin), stimulants (such as cocaine), alcohol, nicotine, benzodiazepines and Z drugs.

How can medicines help drug dependence?

Medicines for drug dependence are mainly used to reduce or prevent withdrawal symptoms. In the short term they help to stabilise the person's drug use and lifestyle while trying to break drug use. In the long term these medicines may help to change the person's drug taking and any risky behaviour.

Sometimes other medicines may be prescribed in addition to the medicine that helps to treat withdrawal symptoms. For example if you have acute alcohol withdrawal symptoms, haloperidol or olanzapine may be prescribed for hallucinations.

Some drug users are often dependent on more than one drug and they may need a combination of medicines to help with dependency.

Which medicines are available to help with drug dependence?

There are several medicines that are used for drug dependence. The choice of medicine prescribed will depend on which drug you are dependent on:

  • Opiates (such as heroin or morphine) - methadone, buprenorphine, lofexidine, and naltrexone may be used to treat opiate withdrawal and dependency.
  • Stimulants (such as cocaine or amfetamines) - benzodiazepines such as diazepam are used to help the patient 'come down'. Antidepressants such as fluoxetine and lofepramine may used to treat any underlying depression. Sometimes a medicine called dexamfetamine is used to treat people who are dependent on amfetamines.
  • Alcohol - chlordiazepoxide is normally used to help at first with acute withdrawal. Carbamazepine or clomethiazole may also be used for acute withdrawal. Haloperidol or olanzapine may be prescribed for hallucinations during acute withdrawal. Acamprosate, naltrexone and disulfiram are used long-term to help prevent you from drinking alcohol again.
  • Benzodiazepines - another benzodiazepine (normally diazepam) is usually prescribed to people who are dependent on benzodiazepines.
  • Nicotine - nicotine replacement therapy (NRT) - for example, patches, gum and sprays - bupropion, or varenicline may be used to treat nicotine dependency.

How are medicines used to treat drug dependence?

Opiates (for example, heroin, morphine, dihydrocodeine and codeine)

Treatment for opiate dependence involves replacing the opiate you have been using with a prescribed opiate. At the start of treatment the main aim is to treat and prevent withdrawal symptoms as well as reduce the risk of harm that is caused to the person and the community because of the drug use. Once stabilised, the dose of the medicine may be gradually reduced with the aim of stopping altogether. Methadone is the opiate that is usually prescribed, but another opiate called buprenorphine may also be used. Sometimes other opiates are used - for example diamorphine, dihydrocodeine, or slow-release morphine tablets.

For more information see separate leaflets called Buprenorphine replacement for heroin and Methadone replacement for heroin.

Stimulants (cocaine and amfetamines)

Unlike opiate dependence, there is no clear guidance on which medicines should be prescribed for people who are dependent on stimulants such as cocaine and amfetamine. As discussed above, benzodiazepines (such as diazepam) can help the patient to 'come down' but this medicine is normally only used for less than two weeks.

Other medicines may be tried by specialist doctors if you are also dependent on other drugs. For example, a medicine called disulfiram may be prescribed if you are also dependent on alcohol. Methadone, buprenorphine and dexamfetamine are sometimes used if you are also dependent on opiates such as heroin.

Sometimes an antidepressant (selective serotonin reuptake inhibitor (SSRI)) may be used if you also have depression. But you must have stopped using stimulants before an SSRI is prescribed. This is because if an antidepressant SSRI and cocaine are used together you can become very unwell and develop serotonin syndrome (overstimulation of the nervous system). Beta-blockers are useful if you also have anxiety during withdrawal and they can help to stop you using cocaine again.


A doctor usually prescribes a high dose of medication such as chlordiazepoxide, or carbamazepine (normally used by a specialist doctor in hospital) for the first day that you stop drinking alcohol. Then the dose is slowly reduced over the next 5-7 days. This usually prevents, or greatly reduces, the unpleasant withdrawal symptoms. This is called detoxification or detox. You may be advised to take a medicine for several months to help you keep off alcohol:

  • Acamprosate is a medicine which helps to ease alcohol cravings. It is usually started in hospital and continued by GPs.
  • Naltrexone is an alternative to acamprosate but it is usually only prescribed by specialists.
  • Disulfiram is another medicine which is sometimes recommended by hospital specialists following a successful detox. When you take disulfiram you get very unpleasant symptoms if you drink any alcohol (such as flushing, vomiting, palpitations and headache). So, in effect, the medicine acts as a deterrent for when you are tempted to drink. It can help some people to stay off alcohol.
  • Baclofen is a medicine that is reported in some medical studies to help some people to stay off alcohol or to reduce drinking quantity. It may also reduce craving and reduce anxiety in alcohol-dependent people. Note: it is currently not licensed for the treatment of alcohol-related problems.

For more information see separate leaflet called Alcohol detoxification.

Benzodiazepines and Z drugs

Some people can stop taking benzodiazepines and Z drugs without any difficulty. However, for a lot of people the withdrawal effects are too severe to cope with if the medicine is stopped suddenly. Therefore, it is often best to reduce the dose gradually over several months before finally stopping it. This keeps withdrawal symptoms to a minimum.

A common plan is to switch from whatever benzodiazepine tablet or Z drug you are taking to diazepam. Diazepam is a long-acting benzodiazepine that is commonly used. Your doctor will be able to prescribe the dose of diazepam equivalent to the dose of your particular type of benzodiazepine or Z drug. After this, you can decide with your doctor a plan of how to reduce the dose gradually. Normally you reduce the dose by a small amount every 1-2 weeks. The amount the dose is reduced at each step may vary, depending on how large a dose you are taking to start with. Also, the last few dose reductions before finally stopping completely may be less than the original dose reductions, and done more gradually.

Sometimes other medication may be prescribed to help you cope with symptoms while you are coming off benzodiazepines. For example, you may be offered antidepressants if depression emerges whilst you are on a withdrawal programme, or beta-blockers if you need help to control anxiety.

For more information see separate leaflet called Stopping benzodiazepines and Z drugs.


Either NRT, bupropion, or varenicline can be prescribed for people who want to stop smoking. You can choose which treatment to have after a discussion with a pharmacist, doctor or nurse about the pros and cons of each of the treatments.

  • NRT - this is available as gum, skin patches, inhalers, tablets/lozenges, nasal spray and mouth spray. Once you have decided which treatment you would like to use, you usually set a date to start. Some people prefer to stop smoking at the end of one day, and start NRT when they wake the following day. Others prefer to use NRT while they are still smoking, as a way of cutting down gradually. NRT is used regularly at first for at least 8-12 weeks. You are normally started off on a high dose which is reduced in the later part of the course, and then stopped. It is not recommended to combine NRT with other medicines that help you stop smoking, such as bupropion or varenicline.
  • Bupropion - you normally start by taking one tablet each day for six days. Then increase to one tablet twice a day, at least eight hours apart. Then you need to set a target date to stop smoking - usually one to two weeks after starting treatment. This allows bupropion to build up in your body before you stop completely. The tablets are continued for a further seven weeks - eight weeks in total. Your blood pressure may go up when you are taking this medicine, and seizures (fits) have also been reported with this medicine - this is rare.
  • Varenicline - you normally start by deciding on a quit date. Then start taking the tablets one week before the quit date. The aim is to build up the dose so your body gets used to the medicine before the quit date. The usual advice is to start with a low dose and build this up over the following 11 weeks. The usual course of treatment is for a total of 12 weeks, but In some cases, an additional 12 weeks of treatment may be advised.

For more detailed information on help for stopping smoking, see separate leaflets called Nicotine replacement therapy, Bupropion (Zyban)® and Varenicline (Champix)®.

Further help and information


Tel: 0800 77 66 00 Web:
National website and 24-hour helpline for people with concerns over drugs and addiction.

The Alliance

Tel: (Helpline) 0845 122 8608 Web:
The Alliance is a user-led organisation which provides advocacy, training and helpline services to those currently in drug treatment, those who have accessed drug treatment in the past and those who may access drug treatment in the future.

Self-help and support groups

A listing of the many groups and organisations that provide information, help and support to people who use drugs, and for their families and carers.