Benzodiazepines and Z-drugs

Published by Bupa's Health Information Team, April 2011.

This factsheet is for people who are taking benzodiazepines and Z-drugs, or who would like information about them.

Benzodiazepines and Z-drugs are a group of medicines that are also known as sleeping tablets. They work on the brain to help with severe sleeping difficulties. Benzodiazepines are also used to treat anxiety and sometimes epilepsy.

Why would I take benzodiazepines and Z-drugs?

Your GP may prescribe a benzodiazepine or a Z-drug if you have severe short-term problems getting to sleep or staying asleep (insomnia). You will usually only be able to have these medicines if other self-help measures to get you to sleep haven’t worked, or your general health has become affected by your lack of sleep.

Benzodiazepines can also be used for the short-term treatment of severe anxiety (known as tranquillisers), or to calm and relax people who are having a stressful or uncomfortable medical procedure (known as sedatives). They can sometimes be used to treat seizures (fits) in epilepsy and muscle spasms in back pain.

You can only get benzodiazepines and Z-drugs on prescription from your GP. They are usually only given for up to three weeks at a time. You shouldn’t use these medicines for long-term treatment because they can cause problems with dependence and withdrawal.

What are the main types of benzodiazepines and Z-drugs?

There are two main types of benzodiazepines. Hypnotics (eg flurazepam, loprazolam and nitrazepam) are mainly used to treat insomnia and anxiolytics (eg alprozolam, chlordiazepoxide and diazepam) are mainly used to treat anxiety. A different benzodiazepine (eg clonazepam) can be used to treat epilepsy.

Most benzodiazepines that are used to treat insomnia are short-acting (eg loprazolam). This means they are less likely to cause a hangover effect, which is when you feel the effects of the medicine the next day, than long-acting benzodiazepines (eg nitrazepam).

Z-drugs (eg zaleplon, zolpidem and zopiclone) are only used to treat insomnia. They work in a similar way to benzodiazepines, but tend to stay in your body for a shorter length of time.

How do benzodiazepines and Z-drugs work?

Benzodiazepines and Z-drugs work by slowing down brain function. They do this by increasing the action of a chemical called gamma-aminobutyric acid. The normal action of this chemical is to tell certain parts of your brain to slow down. Increasing this signal helps to promote sleep and reduce anxiety.

How to take benzodiazepines and Z-drugs

Benzodiazepines and Z-drugs can usually be taken as tablets or as capsules. Some benzodiazepines used for epilepsy come as a solution, a rectal preparation (rectal tubes or suppositories) or an injection.

You should only take benzodiazepines and Z-drugs in the doses prescribed for you. Don’t take more than your GP has recommended, as an overdose of benzodiazepines or Z-drugs can be fatal.

Don’t use benzodiazepines and Z-drugs with alcohol as they could interact and potentially be dangerous.

Always ask your GP for advice and read the patient information leaflet that comes with your medicine.

Special care

If you are a woman and you are pregnant, you shouldn’t take benzodiazepines regularly as your baby may be at risk of getting withdrawal symptoms. You also shouldn’t take them if you are breastfeeding. Older people shouldn’t take hypnotic benzodiazepines as they can cause confusion and loss of coordination, which can lead to falls and injuries.

Side-effects of benzodiazepines and Z-drugs

Benzodiazepines can cause a range of side-effects, including:

• drowsiness
• dizziness
• unsteadiness
• confusion
• light-headedness
• memory loss

Benzodiazepines may also cause you to become more talkative and excited, or aggressive, but this is rare.

Z-drugs have fewer side-effects than benzodiazepines, but can cause:

• drowsiness
• feeling sick
• memory loss

Less commonly, Z-drugs can cause confusion, difficulty concentrating, dizziness and changes to your senses of smell, hearing, speech and vision.

Benzodiazepines and Z-drugs can temporarily affect your coordination and reasoning skills, so you must not drive, drink alcohol, operate machinery or sign legal documents for 24 hours after taking them. If you’re in any doubt about driving, contact your motor insurer so that you’re aware of their recommendations, and always follow your GP’s advice.

Dependence

You shouldn’t take benzodiazepines or Z-drugs for more than a few weeks because they can cause physical and psychological dependence. This means you may find it difficult to stop taking them. It also means you may need to take more of your medicine for it to have the same effect (this is known as tolerance).

Withdrawal

When you stop taking benzodiazepines, you may have some unpleasant symptoms. This is known as benzodiazepine withdrawal syndrome. You may have symptoms such as confusion, insomnia, anxiety, loss of appetite, weight loss, shaking, sweating and ringing in your ears. These symptoms can continue for weeks or months after you’ve stopped taking the medicine. You’re unlikely to have these symptoms if you’ve only taken benzodiazepines for a short time.

You should never suddenly stop taking a benzodiazepine. This can cause some very unpleasant and potentially dangerous symptoms, such as seizures. With your GP’s help and advice, you can stop taking benzodiazepines gradually if you have become dependent on them after long term use. This may take between three to four months, but can be up to a year or longer.

Z-drugs don’t cause withdrawal symptoms in the same way as benzodiazepines, but they can cause dependence.

Interactions of benzodiazepines and Z-drugs with other medicines

You should be aware that all substances that have a tranquillising or sedative effect on your brain, including alcohol, will also increase the effects of benzodiazepines and Z-drugs.

Check with your GP or pharmacist before you take any other medicines or herbal remedies at the same time as a benzodiazepine or Z-drug.

Names of common benzodiazepines and Z-drugs

Examples of the main types of benzodiazepines and Z-drugs are shown in the table.

All medicines have a generic name. Many medicines also have one or more brand name. Generic names are in lower case, whereas brand names start with a capital letter. 

* These branded medications aren’t available on the NHS – only the generic version can be prescribed.

For answers to frequently asked questions on this topic, see Common questions.

For sources and links to further information, see Resources.