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CNS depressants
What are CNS depressants?
CNS depressants, sometimes
referred to as sedatives
and tranquilizers, are substances
that can slow normal
brain function. Because of
this property, some CNS
depressants are useful in
the treatment of anxiety and
sleep disorders. Among the
medications that are commonly
prescribed for these purposes
are the following:
- Barbiturates, such as
mephobarbital (Mebaral)
and pentobarbital sodium
(Nembutal), are used to
treat anxiety, tension, and
sleep disorders.
- Benzodiazepines, such
as diazepam (Valium),
chlordiazepoxide HCl
(Librium), and alprazolam
(Xanax), are prescribed
to treat anxiety, acute
stress reactions, and panic
attacks. The more sedating
benzodiazepines, such as
triazolam (Halcion) and
estazolam (ProSom) are
prescribed for short-term
treatment of sleep disorders.
Usually, benzodiazepines
are not prescribed
for long-term use.
How do CNS depressants
affect the brain and body?
There are numerous CNS
depressants; most act on
the brain by affecting the
neurotransmitter gammaaminobutyric
acid (GABA).
Neurotransmitters are brain
chemicals that facilitate
communication between
brain cells. GABA works
by decreasing brain activity.
Although the different classes
of CNS depressants work in
unique ways, it is through
their ability to increase GABA
activity that they produce a
drowsy or calming effect that
is beneficial to those suffering
from anxiety or sleep disorders.
What are the possible consequences
of CNS depressant use and abuse?
Despite their many beneficial
effects, barbiturates and
benzodiazepines have the
potential for abuse and should
be used only as prescribed.
During the first few days of
taking a prescribed CNS
depressant, a person usually
feels sleepy and uncoordinated,
but as the body becomes
accustomed to the effects of
the drug, these feelings begin
to disappear. If one uses these
drugs long term, the body
will develop tolerance for the
drugs, and larger doses will
be needed to achieve the
same initial effects. Continued
use can lead to physical
dependence and - when
use is reduced or stopped -
withdrawal. Because all CNS
depressants work by slowing
the brain's activity, when an
individual stops taking them,
the brain's activity can rebound
and race out of control, potentially
leading to seizures and
other harmful consequences.
Although withdrawal from
benzodiazepines can be
problematic, it is rarely life
threatening, whereas withdrawal
from prolonged use
of other CNS depressants can
have life-threatening complications.
Therefore, someone
who is thinking about discontinuing
CNS depressant therapy
or who is suffering withdrawal
from a CNS depressant should
speak with a physician or seek
medical treatment.
Is it safe to use CNS depressants
with other medications?
CNS depressants should be
used in combination with
other medications only under
a physician's close supervision.
Typically, they should not
be combined with any other
medication or substance that
causes CNS depression,
including prescription pain
medicines, some OTC cold
and allergy medications, and
alcohol. Using CNS depressants
with these other substances -
particularly alcohol - can slow
both the heart and respiration
and may lead to death.
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