Benzodiazepines

Introduction

Benzodiazepines are a class of sedative/transquilliser drugs used in medical practice to treat anxiety, or induce sleep. The class act on the "benzodiazepine receptor" which regulates the rate of secretion of the inhibitory neurotransmitter GABA (gamma amino butyric acid) in the brain.

The class includes many well-known products, notably diazepam (Valium), temazepam, lorazepam (Ativan), and nitrazepam (mogadon).

Effects and abuse potential

All benzodiazepines have the potential to produce physical or psychological dependence when used in high doses or for a prolonged period of time, with doses of 100mg per day of diazepam or 300mg of chlordiazepoxide liable to cause physical dependence[i]. While it was common for these drugs to be prescribed on a long-term basis between the 1960s and 1980s, the abuse potential has restricted recommended prescribing regimes to a maximum of 2-4 weeks. Short-acting benzodiazepines carry the greatest abuse potential.

Many long-term dependent users of Benzodiazepines were middle-aged or elderly women who acquired their dependency as a result of medical treatment before such dangers were fully-realised.

Among "traditional" groups of drug users, benzodiazepines are rarely the drug of choice, but may be used in a secondary capacity by opiate users when opiates are unavailable, or by stimulant users seeking to "come down". There is a limited market for such drugs, as only a small proportion of those who had tried them reported non-prescription prices.

Side effects of benzodiazepines include Drowsiness and lightheadedness, confusion and ataxia, amnesia may occur, dependence, paradoxical increase in aggression, occasionally headache, vertigo, hypotension, salivation changes, gastrointestinal disturbances, rashes, visual disturbances changes in libido, amnesia, respiratory depression, urinary retention, blood disorders and jaundice; on intravenous injection: pain, thrombophlebitis and rarely apnoea. Driving: drowsiness may affect performance of skilled tasks (e.g. driving). Interactions: effect of alcohol enhanced Alcohol, Neuroleptics, Antidepressants - enhanced sedation

Research on Benzodiazepine Consumption

There is little recent research as to the amounts of benzodiazepines consumed by heavy non-medical drug users. Robson[iii] reported that a large majority of attenders at drug dependency units use benzodiazpines from time to time, 'often in huge doses', and that 'the equivalent of 20-30 times the manufacturers recommended dose is not unusual' due to the development of tolerance.

Our IDMU surveys have shown Benzodiazepine use to be unusual among recreational drug uses, less than 10% of respondents have ever used these drugs, and of those who have used only 5% do so daily. Less than one percent of the overall sample (8% of "ever users) reported buying the drug monthly or more frequently, spending on average a modest £10 to a maximum of £200 per month on these drugs.

Only a handful of respondents who had tried tranquillisers have reported a regular pattern of use or spending on these drugs, the usage of the vast majority falling within prescribing guidelines, with a small minority of excessive users taking up to 10-36 pills a day (2001-2005 data).

As the paper surveys have not distinguished between different types of tranquilliser, the IDMU Web-survey allowed more detailed questions to be asked of respondents. Data from the first two years (2004-05) showed Diazepam to be by far the most common tranquilliser reported by drug users, followed by Temazepam and Lorazepam.