Benzodiazepines
Benzodiazepines are a family of prescription drugs that are central nervous system depressants. Over the last 20 years, they have replaced their predecessors, the barbiturates, which have severe toxic side effects including risk of fatal overdose.
Benzodiazepines are sometimes called 'minor tranquillisers', anxiolytics, sedatives or hypnotics. They should be distinguished from the so-called major tranquillisers which are different drugs that are used to treat illnesses like schizophrenia.
Benzodiazepines are widely prescribed in Australia, and some people consider them to be overprescribed. They may produce a dependence characterised by tolerance and physical and psychological symptoms of withdrawal.
Clinical guidelines for the use of benzodiazepines recommend they be used for short periods for the relief of anxiety or insomnia. Occasionally they may be used long term for chronic anxiety or sleep disturbance.
Benzodiazepines are commonly implicated in 'doctor-shopping' phenomena, where individuals visit multiple doctors to get prescriptions of these drugs. Abuse of the benzodiazepine flunitrazepam (Rohypnol or 'roheys') has necessitated it be placed on a list of highly restricted drugs alongside morphine and amphetamine in most states. Availability and use of benzodiazepines is therefore at least in part dictated by the channels of distribution from medical practitioners.
It is likely that many benzodiazepine users are opportunistic, using them when they are available, as an augment to other drugs or when a drug of preference such as heroin, is unavailable.
Pharmacology
Benzodiazepines appear to exert their anti-anxiety action through the pathways of a neurotransmitter called gamma amino butyric acid (GABA). The half life of benzodiazepines varies depending on the particular member of the family.
Drug name | Half life in hours | Comments |
| Valium. ducene, Antenex (diazepam) | 24 (long acting) | Used for treatment of alcoholism and benzodiazepine dependence; also manufactured in injection form. |
| Serepax, Murelax, Alepam (oxazepam) | 8 (short to medium acting) | Used as an anxiolytic. |
| Normison, Euhypnos, Temaze (temezepam) | 12 | Used as a sleeping pill (hypnotic). There are reports of illicit injection of the contents of gel capsules of temezepam. |
| Rohypnol, Hypnodorm (flunitrazepam) | 25 (long acting) | Hypnotic drug that has a high abuse potential. It has been placed on a restricted prescription listing in all states except NSW |
Usual Routes of Administration
- orally
- injection.
Benzodiazepines are most commonly taken orally. There are injectable forms available but these are not abused much due to limited availability. Also, there has been reports of injection of some forms of benzodiazepines, particularly the soft gel in temezepam capsules.