Last published: June 28, 2022

What are benzodiazepines?

Benzodiazepines (pronounced 'ben-zoh-die-AZ-a-peens') are depressant drugs. Which means they slow down the messages travelling between the brain and the body.1 They don’t necessarily make a person feel depressed. Other depressants include alcohol, cannabis and heroin.

Benzodiazepines also are minor tranquillisers, usually prescribed by doctors to relieve stress and anxiety and to help people sleep.2 They can also be used to treat alcohol withdrawal and epilepsy.2

But, medical professionals have become concerned about their risks, particularly if used over a long time.

Benzodiazepines can cause overdose, particularly when used with alcohol or other drugs. They’re also associated with dependence (addiction) and withdrawal symptoms, even after only using them for a short period. 

This is why benzodiazepines aren’t the first option for the treatment of insomnia, anxiety or other health concerns.3, 4

Some people take benzodiazepines to get ‘high’ or to help with the ‘come down’ effects of stimulants such as amphetamines or cocaine.

What do they look like?

Benzodiazepines are usually a pill or tablet in varying colours and shapes.

Other names

Benzos, tranx, sleepers, downers, pills, xannies, serras (Serepax®), moggies (Mogadon®), normies (Normison®).

Other types of depressants

Types of benzodiazepines

There are three types of benzodiazepines: long, intermediate and short-acting. Short-acting benzodiazepines have stronger withdrawal or ‘come down’ effects and can be more addictive than long-acting ones.2

Benzodiazepines are known by their chemical (generic) name or their brand name. In each case the drug is the same – it’s just made by a different company. Some common benzodiazepines are:

Pharmaceutical names

Generic name Brand name Type
diazepam Ducene®, Valium® Long-acting
oxazepam Alepam®, Murelax®, Serepax® Short-acting
nitrazepam Alodorm®, Mogadon® Intermediate-acting
temazepam Euhypnos®, Normison® Short-acting
alprazolam Xanax®, Kalma®, Alprax® Short-acting

Adapted from: Brands B, Sproule B & Marshman J. (eds) (1998) Drugs & Drug Abuse (3rd ed.) Ontario: Addiction Research Foundation.

How are they used?

Benzodiazepines are usually swallowed. Some people also inject them.

Effects of benzodiazepines

There is no safe level of drug use. Use of any drug always carries some risk. It’s important to be careful when taking any type of drug.

Benzodiazepines affect everyone differently, but the effects may include:

  • depression
  • confusion
  • feelings of isolation or euphoria
  • impaired thinking and memory loss
  • headache
  • drowsiness, sleepiness and fatigue
  • dry mouth
  • slurred speech or stuttering
  • double or blurred vision
  • impaired coordination, dizziness and tremors
  • nausea and loss of appetite
  • diarrhoea or constipation.1

Injecting benzodiazepines may also cause:

  • vein damage and scarring
  • infection, including hepatitis B, hepatitis C, HIV and AIDS
  • deep vein thrombosis and clots which can result in loss of limbs, damage to organs, stroke and possibly death.5

Injecting drugs repeatedly and sharing injecting equipment with other people increases the risk of experiencing these effects.4

Who are benzodiazepines not recommended for?

Benzodiazepines are not recommended for use during pregnancy or breastfeeding, as they are associated with pre-term delivery, low birth weight and potential birth defects.5-7

They may also be dangerous for people with:

  • acute asthma, emphysema or sleep apnoea
  • advanced liver or kidney disease
  • or people with a history of substance use disorders, as their use can lead to dependence.8,9

Benzodiazepines taken by elderly people can increase their risk of falls and injury.


Benzodiazepines are often present in patients who have intentionally or accidentally overdosed.

If you take a large amount or mix them with other drugs, you could overdose. 

Symptoms include:

  • over-sedation or sleep
  • jitteriness and excitability
  • mood swings and aggression
  • slow, shallow breathing
  • unconsciousness or coma
  • death (more likely when taken with another drug such as alcohol).3

Call an ambulance straight away by dialling triple zero (000) if you or someone else has any of these symptoms. Remember, ambulance officers don’t need to involve the police.

Long-term effects

Regular use of benzodiazepines may cause:3,11

  • impaired thinking or memory loss
  • anxiety and depression
  • irritability, paranoia and aggression
  • personality change
  • weakness, lethargy and lack of motivation
  • drowsiness, sleepiness and fatigue
  • difficulty sleeping or disturbing dreams
  • headaches
  • nausea
  • skin rashes and weight gain
  • addiction
  • withdrawal symptoms (see below).3

There is some evidence that long-term, heavy use of benzodiazepines is a risk factor for epilepsy, stroke and brain tumours.12

Using benzodiazepines with other drugs

The effects of taking benzodiazepines with other drugs − including over-the-counter or prescribed medications − can be unpredictable and dangerous.

Benzodiazepines + alcohol or opiates (such as heroin): breathing difficulties, an increased risk of overdose and death.6, 7

Benzodiazepines + some pharmaceutical drugs: strong pain-relievers, antidepressants, anticonvulsants, anti-psychotics, some anti-histamines and over-the-counter medications can have an adverse effect when taken with benzodiazepines and lead to breathing difficulties, an increased risk of overdose and death.7, 8

The use of benzodiazepines to help with the come down effects of stimulant drugs (such as amphetamines or ecstasy) could result in a cycle of dependence on both types of drug.

Use of more than one drug or type of drug consumed at the same time is called polydrug use.10

‘Polydrug use’ is a term for the use of more than one drug or type of drug at the same time or one after another.2 Polydrug use can involve both illicit drugs and legal substances, such as alcohol and medications. More on polydrug use .

Withdrawal from benzodiazepines

Giving up benzodiazepines after a long time is challenging because the body has to get used to functioning without them. So it’s important to seek advice from a health professional when planning to stop taking benzodiazepines. If taking benzodiazepines is suddenly stopped, sudden withdrawal can cause seizures.4,9

Withdrawal symptoms vary from person to person and are different depending on the type of benzodiazepine being taken. Symptoms can last from a few weeks to a year and can include:

  • headaches
  • aching or twitching muscles
  • dizziness and tremors
  • nausea, vomiting, stomach pains
  • bizarre dreams, difficulty sleeping, fatigue
  • poor concentration
  • anxiety and irritability
  • altered perception, heightening of senses
  • delusions, hallucinations and paranoia
  • seizures.3

Getting help

If your use of benzodiazepines is affecting your health, family, relationships, work, school, financial or other life situations, or you’re concerned about a loved one, you can find help and support.

Call DrugInfo on 1300 85 85 84 or email to speak to a real person and your questions answered as well as advice on practical ‘next steps’. It’s confidential too. 


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Using benzodiazepines without a prescription from a doctor, or selling or giving them to someone else, is illegal. 

There are also laws against forging or altering a prescription or making false representation to get benzodiazepines or a prescription for them.10

In 2014, in response to concerns about the use and harms associated with the benzodiazepine alprazolam (Xanax®), it was rescheduled under the Pharmaceutical Benefits Scheme (PBS) as a Schedule 8 drug. Doctors must now follow additional state and territory laws when prescribing alprazolam and must notify, or receive approval from, the appropriate health authority.11


4.7% of Australians aged 14 years and over have used tranquillisers/sleeping pills (including benzodiazepines) for non-medical purposes one or more times in their life.12

1.6% of Australians aged 14 years and over have used tranquillisers (including benzodiazepines) for non-medical purposes in the previous 12 months.12

Young people

Young Australians (aged 14–24) first try tranquilisers for non-medical purposes at 18.2 years on average.13

  1. The Royal Australian College of General Practitioners. Prescribing drugs of dependence in general practice, Part B – Benzodiazepines. Melbourne; 2015.
  2. Zikic O, Nikolic G, Kostic J. Clinical picture of benzodiazepine dependence: The role of different types of benzodiazepines. Journal of Substance Use. 2019;24(4):374-80.
  3. Brands B, Marshman J, Sproule B. Drugs & Drug Abuse: A Reference Text: Addiction Research Foundation= Fondation de la recherche sur la toxicomanie; 1998.
  4. European Monitoring Centre for Drugs and Drug Addiction. Benzodiazepines drug profile: European Monitoring Centre for Drugs and Drug Addiction; 2015 [cited 2019 25 November].
  5. Shyken JM, Babbar S, Babbar S, Forinash A. Benzodiazepines in Pregnancy. Clinical Obstetrics & Gynecology. 2019;62(1):156-67.
  6. Tinker SC, Reefhuis J, Bitsko RH, Gilboa SM, Mitchell AA, Tran EL, et al. Use of benzodiazepine medications during pregnancy and potential risk for birth defects, National Birth Defects Prevention Study, 1997-2011. 2019. p. 613-20.
  7. Benzodiazepine use in early pregnancy heightens risk of spontaneous abortion. Brown University Psychopharmacology Update. 2019;30(9):1-6.
  8. Upfal J. The Australian drug guide : every person's guide to prescription and over-the-counter medicines, street drugs, vaccines, vitamins and minerals. 8th ed. ed: m2m Direct Pty Ltd; 2016.
  9. O’Brien PL, Karnell LH, Gokhale M, Kenneth Pack BS, Campopiano M, Zur J. Prescribing of benzodiazepines and opioids to individuals with substance use disorders. Drug and alcohol dependence. 2017;178:223-30.
  10. The Royal Australian & New Zealand College of Psychiatrists. Guidance for the use of benzodiazepines in psychiatric practice. 2015.
  11. Crowe SF, Stranks EK. The Residual Medium and Long-term Cognitive Effects of Benzodiazepine Use: An Updated Meta-analysis. 2018. p. 901-11.
  12. Harnod T, Wang Y-C, Kao C-H. Association between benzodiazepine use and epilepsy occurrence: a nationwide population-based case–control study. Medicine. 2015;94(37).


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