Antianxiety Drugs

These drugs are central nervous system depressants. Many of these antianxiety
drugs or anxiolytics are, in higher doses, also used as sedativehypnotics,
or calming and sleep-inducing drugs. They seem to act by enhancing
the effect of GABA in the brain. The earliest of these depressant
drugs included chloroform, chloral hydrate, and paraldehyde, and they
were used for anesthesia and for sedation.
Barbiturates were introduced in Germany in 1862 and were widely used
for treatment of anxiety and sleep problems until the 1960’s. Barbiturates
are still available today, including pentobarbital, secobarbital, amobarbital,
and phenobarbital. Their major adverse effect is respiratory depression,
particularly when used in combination with alcohol, another central nervous
system depressant.With the advent of the safer benzodiazepines, use of
the barbiturates has declined steadily.

Benzodiazepines are used for two major problems: anxiety and insomnia.
Anxiety disorders appropriate for this kind of treatment include generalized
anxiety disorder, panic disorder, obsessive-compulsive disorder, phobic
disorder, and dissociative disorder. The benzodiazepines commonly used
for anxiety include alprazolam, chlordiazepoxide, clonazepam, clorazepate,
diazepam, lorazepam, and oxazepam. For most of these disorders,
however, behavioral, cognitive, group, and social therapy, or one of these
therapies plus medication, are more effective than medication alone. Benzodiazepines
used for insomnia include estazolam, flurazepam, midazolam,
quazepam, temazepam, and triazolam. Benzodiazepines may also be used to
prevent the development of delirium tremens during alcohol withdrawal.
Patients become tolerant to the effects of these drugs, meaning they have
the potential for physical dependency and addiction. In addition, benzodiazepines
interact with many other drugs, including alcohol. Their use
should be limited to brief periods of time, particularly in the treatment of insomnia.
Long-term treatment for anxiety should be monitored carefully by
the health care provider. Elderly people are more likely than younger people
to suffer adverse effects (such as confusion or falls) from benzodiazepine
use.
Another drug developed for treatment of anxiety is buspirone. Propranolol
and atenolol, usually used to treat high blood pressure, are useful in
treating stage fright or performance anxiety, and clonidine, another blood
pressure medication, is successfully used in treatment of anxiety. Nonbenzodiazepine
sleep agents include zolpidem and zaleplon.