Addiction Medicine: Closing the Gap between Science and Practice

Pharmaceutical agents for addiction treatment
may work via one of the following mechanisms
of action or by a combination of these
mechanisms:*

 Reducing cravings for the addictive
substance and/or reducing aversive
withdrawal symptoms;

 Creating an aversion to the addictive
substance or attenuating the rewarding
effects of the addictive substance, eventually
limiting its appeal; or

 Producing moderated effects resembling
those of the addictive substance and serving
as a less addicting replacement for the
substance of addiction.

Differences in the factors that contribute to
addiction and that determine how the disease
will manifest itself† require different and tailored
approaches to treatment, particularly with regard
to pharmaceutical treatments. For example,
individuals with addiction involving alcohol
who drink primarily for the rewarding effects
may be quite different biologically from those
who drink primarily as a means of relieving
stress or reducing negative feelings; as such, the
efficacy of a specific pharmaceutical treatment
may depend on whether it addresses the reward
experienced from using the addictive substance
or whether it serves as a safer medication for
providing relief from negative feelings.^96
Likewise, certain genetic or biological
characteristics may determine how effective a
certain type of pharmaceutical intervention will
be for an individual with addiction; for example,
naltrexone has been found to be a more effective
medication for the treatment of addiction

• For ease of presentation, a medication is categorized

in this discussion based on its primary mechanism of
action.
† In individuals with a significant genetic

susceptibility, progression from use to addiction is
relatively quick and severe, whereas in individuals
with a low genetic susceptibility, progression from
use to addiction will result from prolonged exposure
to addictive substances and considerable
environmental risk factors, such as stress. (See
Chapter II.)

involving alcohol in patients with a family

history of the disease than in those without a

family history.^97 A true understanding of these

differences is in its infancy, but appears to be a

critical factor in tailoring pharmaceutical

treatments to achieve the maximum therapeutic

benefit.^98

Medications that Reduce Craving and/or

Withdrawal Symptoms. A number of

medications work on the brain chemicals and

pathways of individuals with addiction to reduce

cravings for the addictive substance and in some

cases reduce symptoms of withdrawal from the

substance.

Acamprosate (brand name Campral), approved

by the Food and Drug Administration (FDA) in

2004 to treat addiction involving alcohol, helps

to normalize brain activity and function that has

been disrupted by heavy alcohol use^99 and

reduce withdrawal symptoms such as anxiety

and insomnia.^100 It is prescribed for treatment

patients who have discontinued their use of

alcohol.^101

Studies regarding the effectiveness of

acamprosate have been mixed in the U.S., but

more consistently positive in Europe.‡ 102

Several large-scale, controlled studies have

found that acamprosate can double the

abstinence rate among treatment patients at one

to two years following program completion

compared to patients who receive placebos, and

‡ The differences in effectiveness findings appear to

be due to methodological differences.

What we hope to do is to actually have a menu

of treatments that clinicians could choose from.

If one drug doesn’t work or they can’t tolerate

it,” patients would “try another one and so

forth, and hopefully they’ll find one that is

effective.”^95

--Raye Z. Litten, PhD

Associate Director

Division of Treatment and Recovery Research

National Institute on Alcohol Abuse

and Alcoholism (NIAAA)