Last published: November 10, 2021

What are benzodiazepines?

Benzodiazepines (pronounced 'ben-zoh-die-AZ-a-peens') are drugs which slows down messages travelling between the brain and body. Other depressants include alcohol, cannabis and heroin.

Benzodiazepines are also minor tranquillisers, usually prescribed by doctors to relieve stress and anxiety and to help people sleep. They can also be used to treat alcohol withdrawal and epilepsy. However, medical professionals have become concerned about their risks, particularly when they are used for a long time.

Benzodiazepines can cause a person to overdose, particularly when used with alcohol or other drugs. They are associated with dependence and withdrawal symptoms, even after a short period of use which is why benzodiazepines are not the first option for pharmacological treatment of insomnia, anxiety or other health concerns.1

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

Slang 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.

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.

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

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.10


Benzodiazepines are often present in patients who have intentionally or accidentally overdosed. If you take a large amount, you could overdose. Call an ambulance straight away by dialling triple zero (000) if you have any of the symptoms below (ambulance officers don’t need to involve the police):

  • 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

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, and could cause:

  • Benzodiazepines + alcohol or opiates (such as heroin): breathing difficulties, an increased risk of overdose and death.
  • 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.8

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


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.1

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, you can find help and support.

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 obtain benzodiazepines or a prescription for them.4

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.5


  • 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.6
  • 1.6% of Australians aged 14 years and over have used tranquillisers (including benzodiazepines) for non-medical purposes in the previous 12 months.6

Young people

  • Young Australians (aged 14–24) first try tranquilisers for non-medical purposes at 18.2 years on average.6
  1. Brands B, Sproule B & Marshman J. (eds) (1998) Drugs & Drug Abuse (3rd ed.) Ontario: Addiction Research Foundation.
  2. European Monitoring Centre for Drugs and Drug Addiction (EMCDDA). (2013). Benzodiazepines. Retrieved from the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA).
  3. Upfal J. (2006) The Australian Drug Guide (7th Ed.) Melbourne: Black Inc.
  4. Drugs, Poisons and Controlled Substances Act 1981 – Sect 36B.
  5. Australian Government Department of Health. (n.d). Prescribing Medicines – Information for PBS Prescribers.
  6. Australian Institute of Health and Welfare. (2017). National Drug Strategy Household Survey detailed report 2016. Canberra: AIHW.


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