Anxiolytic drugs:
dependence, addiction and abuse
by
Lader M
Department of Clinical Psychopharmacology,
Institute of Psychiatry, London,
UK.
Eur Neuropsychopharmacol 1994 Jun; 4(2):85-91
ABSTRACT
The concepts of dependence, addiction and abuse comprise overlapping clinical
phenomena. The earlier anxiolytic drugs, in particular the barbiturates, were
prone to abuse, i.e., non-medical use, and to high-dose misuse. Their modern
counterparts, the benzodiazepines, are abused in a patchy way and are sometimes
taken in regularly high doses. However, the main problem is physical dependence
as manifested by a withdrawal syndrome on discontinuation of the drug. The
withdrawal syndrome has been carefully described and comprises physical and
psychological features. In particular, perceptual symptoms such as photophobia,
hyperacusis and feelings of unsteadiness may predominate. The syndrome may come
on during dosage reduction but generally starts 2-10 days after cessation of the
benzodiazepine, depending on its elimination half-life. About a third of
long-term users suffer a recognisable syndrome even after a tapered withdrawal,
its duration usually being only a few weeks. A few patients go on to a prolonged
withdrawal syndrome, often characterised by muscular spasm. The treatment of the
withdrawal syndrome is supportive and non-specific. A few patients started on
benzodiazepine therapy escalate the dose. They tend to show the characteristic
'passive-dependent' personality features and may previously have misused other
CNS depressants such as the barbiturates and alcohol. Abuse of benzodiazepines
occurs in a rather varied way from country to country. Worldwide, flunitrazepam
has caused concern but, in the UK, the main problem has been the intravenous use
of temazepam. The molecular pharmacology of the benzodiazepine receptor has been
extensively studied and is undoubtedly complex.
Ligands
Sedatives
Alprazolam
Temazepam
Barbiturates
Benzodiazepines
Temazepam to counter shift lag
Temazepam (Restoril): structure
Temazepam and elderly insomniacs
Temazepam (Restoril) and injecting drug users