Dependence on a substance means that you need that particular substance to function normally. Drug dependence can result from prescribed drugs, recreational drugs or medicines available over the counter. Drug dependence is a treatable medical condition. 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 your body has become so used to having that drug regularly that you need that particular drug to function normally, and if it were stopped you would feel unwell. Some drugs that cause dependence include nicotine, morphine, heroin (also known as diamorphine), cocaine, amfetamine and alcohol. In addition some people can become dependent upon medicines that are prescribed or bought from their local pharmacy. People who have drug dependence may have psychological dependence and/or physical dependence and/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:
- Feeling hot and cold.
- Runny eyes and nose.
- Being off food.
- Stomach cramps.
- Feeling sick (nausea) or being sick (vomiting).
- Poor sleep.
- General aches and pains.
- 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 started taking that drug.
Examples of some drugs that cause dependence include nicotine, morphine, heroin (also known as diamorphine), cocaine, amfetamine and alcohol. Some people can also become dependent on medicines that are on prescription. Examples are:
- The Z drugs (called thus because they begin with the letter Z: zopiclone, zolpidem and zaleplon).
- Benzodiazepines (for example, lorazepam, lormetazepam,diazepam).
- Other medicines that can be bought from pharmacies - for example, over-the-counter painkillers.
Addiction is slightly different to dependence although the words are sometimes used interchangeably. If you are addicted to a drug, there is an excessive craving, and uncontrollable and compulsive use of that drug. People who are addicted still get cravings for drugs such as opioids even after they have reduced them slowly so that they are no longer dependent. Some people are more likely to develop addiction than others, and seem to be particularly sensitive to the cravings. People can develop dependence on a drug but not be addicted.
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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 be 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 - a longer-acting benzodiazepine (normally diazepam) is usually prescribed to people who are dependent on short-acting benzodiazepines as this is less likely to produce withdrawal effects. The dose of this can then very slowly be reduced.
- Nicotine - nicotine replacement therapy (NRT) such as patches, gum and sprays, bupropion, or varenicline may be used to treat nicotine dependency. NRT is best used as part of a smoking cessation programme.
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 aims are:
- To treat and prevent withdrawal symptoms.
- To 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.
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'. However, this medicine is normally only used for less than two weeks. Supportive 'talking treatments' (psychological therapies) seem to be more effective than medication.
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. However, 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 diazepam (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 following 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. It is better known as the name of one of the brands, Antabuse®. When you take disulfiram you get very unpleasant symptoms if you drink any alcohol - for example:
- Being sick (vomiting).
- A 'thumping' heart (palpitations).
- Nalmefene is a newer medicine which is sometimes recommended by specialists to help people cut down on very excessive alcohol intake.
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.
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. See the separate leaflet called Nicotine Replacement Therapy for more detail.
- 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 fits (seizures) have also been reported with this medicine - this is rare. See the separate leaflet called Bupropion (Zyban) for more details.
- 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. See the separate leaflet called Varenicline (Champix) for more details.
How to use the Yellow Card Scheme
If you think you have had a side-effect to one of your medicines you can report this on the Yellow Card Scheme. You can do this online at www.mhra.gov.uk/yellowcard.
The Yellow Card Scheme is used to make pharmacists, doctors and nurses aware of any new side-effects that medicines or any other healthcare products may have caused. If you wish to report a side-effect, you will need to provide basic information about:
- The side-effect.
- The name of the medicine which you think caused it.
- The person who had the side-effect.
- Your contact details as the reporter of the side-effect.
It is helpful if you have your medication - and/or the leaflet that came with it - with you while you fill out the report.
Further reading and references
British National Formulary (BNF); NICE Evidence Services (UK access only)
Opioid dependence; NICE CKS, April 2015 (UK access only)
Marshall K, Gowing L, Ali R, et al; Pharmacotherapies for cannabis dependence. Cochrane Database Syst Rev. 2014(12):CD008940. doi: 10.1002/14651858.CD008940.pub2. Epub 2014 Dec 17.
Castells X, Cunill R, Perez-Mana C, et al; Psychostimulant drugs for cocaine dependence. Cochrane Database Syst Rev. 2016 Sep 279:CD007380. doi: 10.1002/14651858.CD007380.pub4.