benzos, downers, sleepers, valium, Xanax, Kalma, rowies, seros, temazzies, tranks, tranquillisers, v, vals, normies, roofies, xanies, bricks, rivies, aunty val

Benzodiazepines belong to a group of central nervous system depressants called minor tranquilisers. They come as pills in a variety of colours and shapes, according to the brand.

Close up of scattered pills of different shapes and sizes

The first benzodiazepine (chlordiazepoxide) was synthesised in 1954 in Austria. It was discovered by chance during research on chemical dyes, and found to be a very effective tranquiliser. It was marketed in 1959 under the brand name Librium.

Valium was released in 1963 and became widely used. Since then many other benzodiazepines have been developed.

Common benzodiazepines and their trade names

  • diazepam —Valium, Ducene, Antenex, Valpam
  • oxazepam —Serepax, Murelax, Alepam
  • nitrazepam —Mogadon, Alodorm
  • temazepam —Normison, Temaze, Temtabs
  • lorazepam —Ativan
  • flunitrazepam —Rohypnol, Hypnodorm
  • bromazepam —Lexotan
  • clonazepam —Rivotril, Paxam
  • alprazolam —Xanax, Kalma
  • clobazam — Frisium

Benzodiazepine-like drugs

  • zolpidem - Stilnox, Ambien
  • zopiclone - Imovane, Zimovane

Benzodiazepines and the law

Benzodiazepines can be prescribed by doctors and are legal if used as prescribed.

It is illegal to use benzodiazepines without a prescription, or to give or sell them to other people.

If you are under the influence of drugs (including prescription drugs prescribed to you), it is not legal to drive a car. All benzodiazepines dispensed from a pharmacy will come with a label warning you not to drive a car or operate machinery when affected by them.

How benzodiazepines are used

Benzodiazepines are widely prescribed in Australia for problems such as anxiety and insomnia. They can also be prescribed for epilepsy, alcohol withdrawal, and agitation in severe psychiatric disorders. Prescribed benzodiazepines are taken orally as pills. Because there is a high risk of dependence, benzodiazepines are usually prescribed for short-term use only.

Benzodiazepines are also used illegally as recreational drugs. In this case they may be ground to a powder, mixed with water and injected, as well as being swallowed as pills.

Benzodiazepines statistics

The 2022-23 National Drug Strategy Household Survey reported that non-medical use of tranquillisers/sleeping pills in the 12 months preceding the survey declined between 2019 and 2022-23, from 1.8% to 1.6%.

The lifetime figure for non-medical use of tranquillisers/sleeping pills also decreased, from 4.9% in the 2019 survey to 3.9% in 2022-23.  


Short-term effects

The immediate effects of taking benzodiazepines include:

  • a feeling of relaxation, sleepiness and lack of energy
  • dizziness
  • euphoria
  • confusion
  • visual distortions
  • moodiness
  • short-term memory loss.

Benzodiazepines take around 30 minutes to work when they are swallowed as pills, because they have to be digested before the drug can enter the blood stream. Injected benzodiazepines have an almost immediate effect.

Like other depressants, benzodiazepines affect both physical and mental performance, reducing coordination, slowing reaction times and impairing memory. There is increased risk of accidents and falling, and impairment of performance in tasks such as driving.

Different benzodiazepines are processed by the digestive system and eliminated from the body at different rates. For example, the effects of one of the more common short-acting benzodiazepines, temazepam, reach a peak after two or three hours; the drug ceases to be effective after about six to eight hours. The effects of diazepam (Valium), on the other hand, peak after 30 to 90 minutes, while the drug remains in the blood for up to three days.

There is also considerable variation between individuals, depending on various factors such as age and liver health.

Long-term effects

There is a long list of adverse physical and mental effects are associated with long-term benzodiazepine use, including:

  • anxiety, irritability, paranoia, aggression, and depression
  • muscle weakness, rashes, nausea and weight gain
  • sexual problems
  • menstrual irregularities
  • memory loss, cognitive impairment, dementia and falls
  • confusion, lethargy and sleep problems.

Risks of injecting benzodiazepines

Injecting any drug can lead to serious health problems, including collapsed veins, cellulitis (infection of the deep layers of the skin) and the spread of blood-borne viruses such as HIV and hepatitis. Injecting benzodiazepines can have even more serious effects. Benzodiazepine tablets must be dissolved before they can be injected, and the result is a sticky or lumpy fluid that has the potential to damage the circulation. Although injecting benzodiazepines is fairly uncommon, the consequences can be serious, such as: organ damage, loss of limbs, stroke and, occasionally, death.

Benzodiazepines and driving

Benzodiazepines can cause drowsiness, confusion, and slowed reaction times. It is dangerous, as well as illegal, to drive while affected by benzodiazepines.

If you have been prescribed benzodiazepines, you should not drive if your doctor has advised you not to, or if you experience symptoms of drowsiness or confusion.

Benzodiazepines and pregnancy

Benzodiazepines cross the placenta to the unborn baby. High doses can cause the baby to be born with poor muscle tone, poor feeding ability, drowsiness and low body temperature.

The use of opioids with benzodiazepines increases the risk of neonatal abstinence syndrome (NAS) – a group of problems that occur in a newborn who was exposed to addictive opiate drugs while in the mother’s uterus.

A woman who is pregnant or is planning a pregnancy, and who has been prescribed benzodiazepines, should discuss this with her doctor.

Using benzodiazepines with other drugs

Using benzodiazepines with alcohol, which, like benzodiazepines, is a depressant, has been shown to increase the risk of dying from sedative overdose.

Heroin users sometimes use benzodiazepines as a substitute for heroin if it is unavailable. Benzodiazepines can also be used both to help withdrawal from heroin, and to increase its effects. Since heroin is another depressant, however, combining the two drugs greatly increases a person's risk of dying from a heroin overdose - benzodiazepines are involved in about a quarter of heroin overdose deaths.

People who use amphetamines and ecstasy often use benzodiazepines to help them relax or sleep when they are recovering from the effects of these stimulant drugs.


Benzodiazepines are highly addictive, and are therefore prescribed only for short-term use. Tolerance can develop quickly; this means that dosage must be increased to get the same effect, increasing the chances of dependence. It is possible to become dependent and suffer withdrawal symptoms after only two weeks of regular use. Dependence can result in cravings and/or physical withdrawal symptoms when benzodiazepines are stopped.


Common symptoms of benzodiazepine withdrawal are often those for which the drugs were prescribed in the first place, such as insomnia, anxiety and irritability. Other possible symptoms include headaches, nausea, tremors, sweating, loss of appetite, visual and hearing disturbances, digestive disturbances, hallucinations and seizures.

Symptoms can be decreased by gradually reducing the dose rather than stopping suddenly.

If you have been using benzodiazepines for a long time you should seek medical advice before tapering off them.


Overdosing on a benzodiazepine alone rarely results in death, although high doses of benzodiazepines can lead to unconsciousness or even coma. A person who has taken an excessive dose can die by passing out and suffocating on vomit or mucus.

Benzodiazepines are commonly implicated in overdoses with multiple medications or substances. If benzodiazepines are taken with other depressants, such as alcohol, heroin or prescribed pain medication, the possibility of fatal overdose is increased.


Treatment for benzodiazepine dependence involves a gradual withdrawal of the drug under medical supervision. Doses are often reduced gradually over weeks or months.

Psychological treatments aimed at keeping the person motivated and improving their coping skills are recommended to maintain recovery. Where anxiety or insomnia were part of the original reason for using benzodiazepines, treatments like cognitive behavioural therapy (CBT) can be useful to develop other strategies to deal with these symptoms without using benzodiazepines. Research shows that in the long term CBT can be more effective than benzodiazepines for insomnia and anxiety. Good social support can also be very helpful.


Useful links