Previous reviews of pharmacologic treatments for
alcohol dependence have
focused on opiate antagonists, such as naltrexone (ReVia)
and nalmefene
(Revex).
This review focuses on acamprosate (Campral), which is
another type of drug
that may help alcoholics maintain abstinence by preventing
relapse. This
drug is not yet approved for use in the United States. In
studies in Europe,
Campral appeared to decrease the return to drinking, following a
brief period
of abstinence, that is typical of alcohol dependence. Campral
does not work
through opiate receptors, but is commonly thought to work by
modifying the
action of GABA, a neurotransmitter. The evidence for action via
GABA
receptors is based on structural similarities and in vitro data,
and Campral
does not share most of the other effects of GABA receptor
modifying drugs.
It's therefore likely that the effects of Campral are mediated
some other
way. When that mechanism is determined, it may open up new
avenues for
development of other, more effective medications for alcoholism
treatment. CampralŪ
|
Brand Name: |
CampralŪ (AotalŪ in France) |
|
Active Ingredient: |
acamprosate |
|
Strength(s): |
probably 333 mg tablet, as in
Europe |
|
Dosage and Form(s): |
1-2 grams/day, oral, expected if
approved for alcoholism |
|
Pregnancy Category: |
probably C - see Drug Safety in
Pregnancy for general
information |
|
Company Name: |
Merck-Lipha (France) |
|
Availability: |
Prescription only, when
available in U.S. |
|
Date Approved in U.S. by FDA: |
approved in France and
many other European countries since 1989. |
What is Campral used for?
Campral may may help alcoholics maintain abstinence by
preventing relapse.
Campral (acamprosate) is not yet approved in the U.S. for
alcoholism
treatment, but limited clinical trials and use in Europe
indicate that it is
effective for decreasing relapse to heavy drinking in abstinent
alcoholics.
Like other drugs used to prevent relapse in recovering
alcoholics, Campral is
thought to reduce the pleasurable effects of alcohol ingestion.
The purpose
is to help the patient maintain abstinence until adequate
self-motivation for
abstinence has been established. Campral will not produce an
Antabuse-like
reaction if alcohol is ingested while receiving the drug.
Acamprosate might also be an option for recovering alcoholic
patients for
whom other medications (such as disulfiram and naltrexone) are
ineffective in
decreasing relapse, or for those who experience serious or
intolerable side
effects from the other drugs. One advantage of acamprosate is
that it not
substantially metabolized (inactivated) in the liver, and can,
therefore, it
can be used even in alcoholics with liver disease.
Mechanism of action:
Campral (acamprosate) has in vitro affinity for GABA type A
and GABA type B
receptors, so it's been assumed that the therapeutic effects of
acamprosate
are due to actions on GABA receptors. However, acamprosate does
not share
most of the other effects of GABA receptor modifying drugs, such
as
antianxiety, hypnotic, or muscle relaxant activity. It's
therefore possible,
perhaps likely, that the effects are mediated some other way.
Acamprosate is
structurally related to l-glutamic acid (l-gutamate), which is
an excitatory
neurotransmitter. It's been proposed that acamprosate decreases
the effects
of the naturally-occurring excitatory neurotransmitter glutamate
in the body.
Since chronic alcohol consumption disrupts this system, and the
changes last
many months after alcohol ingestion is stopped, it's possible
that
acamprosate somehow restores the glutamate system towards
normal. It's
thought, no matter how it acts, that Campral decreases the
pleasant "high"
associated with alcohol consumption, and thus decrease the
frequency of
relapse during abstinence.
Contraindications:
Campral should not be used or used with caution if any of the
following
conditions are present:
- pregnant women and lactating women
- kidney disease
- very severe liver disease
Side effects:
This is NOT a complete list of side effects reported with
Campral. The list
of side effects will most likely increase if the drug is
approved and widely
used in the United States. Currently-known side effects are
usually
transient and mild.
- diarrhea
- dyspepsia (indigestion)
- headache
- nausea and vomiting
- rash, itching
Drug Interactions:
Interactions of Campral (acamprosate) with other medications
are not
well-studied. However, Campral does not appear to interact with
other
medications often used during alcoholism treatment, such as
disulfiram
(Antabuse) and naltrexone (ReVia), or with antianxiety,
antidepressant, or
hypnotic (sleep-inducing) medications. Additional drug
interaction
information should be forthcoming.
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