About Benzos

What are benzodiazepines (Benzos)?

Let’s start with the basics …

Benzodiazepines (‘Benzos’ – slang terms include bennies, jellies, vallies, zops, diazzies, blues, moggies) are some of the most widely prescribed drugs in the world. If you notice ‘pam’ on the end of the drug name on your prescription, you might want to check to see if this IS a Benzo. Not all of them end in ‘pam’ – for instance Chlordiazepoxide is Librium.

Most of them have two names; first there’s the brand name – like Nurofen is for Ibuprofen. You might recognise names like Valium (Diazepam) and Chlordiazepoxide (Librium). These are marketed as tranquillisers because they are long acting and the idea is that they will keep you calm throughout the day.

Other Benzos are marketed as sleeping pills and the reason for that is that they are short acting, which is supposed to prevent you from having a ‘hangover’ (remaining sleepiness) in the morning. These are drugs like Loprazolam (Dormonoct), Oxazepam (Oxanid) and Temazepam (Normison)

Shorter acting drugs tend to cause more problems in withdrawal because their effects don’t last as long.

There are lots and lots of others, and some of these have mid-range effects. Mogadon (Nitrazepam) and Ativan (Lorazepam) are two of these.

These days Benzos are prescribed under their generic names (the ‘pam’s) rather than their brand names and this has been the case since the mid-80’s

So what are ‘Z’ drugs?

“But what I get is called Zopiclone. What’s that? Is it a Benzo?”

After Benzos were already regularly in use, the Z drugs came along. Z drugs are Zopiclone and Zolpidem, and they are marketed as sleeping pills.

There was a third ‘Z’ drug (Zaleplon) but as of 3 July 2015, the European Commission withdrew the marketing authorisation for Sonata (zaleplon) in the European Union (EU).

They affect some of the same, very specific, receptor sites in the brain used by benzodiazepines. Their action is therefore similar. Prescribing advice (BNF) is that they should not be used long term.

In 2004 NICE (National Institute for Health and Care Excellence) brought out a report which says (amongst many other things) that

“…(the Z-drugs) are nonbenzodiazepine hypnotics. Although the Z-drugs differ structurally from the benzodiazepines, they are also agonists of the GABA receptor complex and therefore enhance GABA-mediated neuronal inhibition. The Z-drugs were developed with the aim of overcoming some of the disadvantages of benzodiazepines – for example, next day sedation, dependence and withdrawal.”

“The Summary of Product Characteristics (SPC) specifies that treatment should be as short as possible with a maximum duration of 2 weeks.”

“In common with the benzodiazepines, the sedative effects of the Z-drugs may persist into the next day. The SPCs for … Z-drugs carry warnings about their potential to cause tolerance, dependence and withdrawal symptoms.”

Can’t make sense of this? In other words, Z drugs act similarly to, and are as addictive as Benzodiazepines, in pretty much the same way. Most compiled lists of Benzos now contain Z drugs as well.

The technical stuff

One of the key differences between different benzodiazepines is how long their effects are intended to last.

You will hear and read a lot about ’half-life’ of Benzos. This means how long it takes the blood concentration of the drug to reach half its original level. This should not be confused with the length of time that the therapeutic effects last i.e. how long before you know you need the next pill.

The longer acting drugs are more often used as “tranquillisers”, because their therapeutic effect lasts longer. Longer acting drugs may produce withdrawal symptoms several weeks after a reduction in dose. Two to three weeks is typical but longer periods are not uncommon. This may lead to users being caught in a cycle of continually increasing and decreasing their drug. After cutting their dose they may feel better for a day or two and think that they are on the right path. If they get a withdrawal reaction several weeks later they assume that it can’t possibly be the drug – there must be something wrong with them. Furthermore the drug seems to fix the problem. In reality all the drug may be doing is to reduce its own withdrawal symptoms.

Some benzodiazepines have other uses, and they are widely used in hospitals (e.g. pre-medication before operations), and for treatment of epilepsy.

Benzodiazepines are sometimes termed “minor tranquillisers” as opposed to “major tranquillisers” which are antipsychotic drugs. The term “minor” can be misleading and could result in underestimating the effects of these drugs.

Is my drug a Benzo?

These are commonly prescribed Benzos

Generic names Examples of common brand names
Benzodiazepines mainly for anxiety (anxiolytics)
chlordiazepoxide Librium
diazepam Dialar, Rimapam, Tensium, Valium
lorazepam Ativan
oxazepam Currently no branded versions of the medicine available in the UK.
Benzodiazepines mainly used as sleeping tablets or sedatives (hypnotics)
loprazolam Currently no branded versions of the medicine available in the UK.
lormetazepam Currently no branded versions of the medicine available in the UK.
nitrazepam Mogadon, Somnite
temazepam Serenid-d/forte
clonazepam Rivotril
‘Z’-drugs (sleeping tablets)
Zopiclone Zimovane
Zolpidem Ambien



Reviewed by Rachael Mayfield-Blake, Bupa Heath Information Team, June 2013

These are drugs now only available on a private prescription

Generic names Examples of common brand names
Alprazolam Xanax
Bromazepam Lexotan
Clobazam Frisium
Clorazepate Tranxene
Flunitrazepam Rohypnol
Flurazepam Dalmane