 An
estimated 17% of Canadians are considered high-risk drinkers,
according to the 2004 Canadian Addiction Survey. Nearly
a quarter of those individuals reported that their drinking
has caused harm to themselves or to other people in their
lives. Many might be patients of yours who are desperately
looking for a way to escape the clutches of their drinking
habit. Few resources are available to people with alcohol
addiction problems. The most common therapies available
include behavioural treatments, addiction counselling
and support groups like Alcoholics Anonymous.
The opioid antagonist naltrexone
has shown it can help addicts cut down on consumption
by blocking the neural pathways through which alcohol
acts. But compliance is an issue. A new long-acting
form of the drug might offer hope to people who want
to kick the habit. A study published in the April 6
issue of the Journal of the American Medical Association
(JAMA) shows that a monthly shot of long-acting
naltrexone can help alcoholics decrease heavy drinking
episodes as they work towards overcoming their addiction.
"We know that many alcoholics have
problems with compliance with a day-to-day pill and
the injection helps address this," says study author
Dr James Garbutt of the Department of Psychology at
the University of North Carolina at Chapel Hill. "Long-acting
naltrexone is a valuable addition to our medication
toolbox because it provides a mechanism to ensure that
medication is in an individual's system for a full month."
ENCOURAGING
RESULTS
The JAMA study, funded by the biotech company
that manufactures the drug, Alkermes Inc, is one of
the largest trials to look at treatment for alcoholics.
Researchers recruited 627 healthy participants clinically
diagnosed with alcohol dependency from 24 medical centres
across the US.
In the month prior to starting
the trial all participants had experienced at least
two incidents of heavy drinking per week — defined
as five or more drinks per day for men and four or more
drinks per day for women. Clinically speaking, heavy
drinking is the leading cause of liver damage, impaired
driving, interpersonal problems and injuries.
The 627 participants were randomized
to receive a monthly shot of either 380mg or 190mg of
naltrexone or placebo. They also had access to 12 sessions
of low-intensity therapy during the six-month trial.
Those who received 380mg of naltrexone
per month experienced 25% fewer heavy drinking days
over the course of the trial as compared to the placebo
group. The median percent reduction in heavy drinking
days of this group was 48%. The average reduction in
the number of drinking days was even lower, as it was
less inflated by the handful of participants that drank
very heavily.
The 190mg treatment was also effective
albeit to a lesser extent than the high dose, with 17%
fewer heavy drinking days than the control group. Moreover,
at this dosage, naltrexone appears to have few side
effects like nausea, headache and fatigue. In the course
of the trial, dropout due to adverse events occurred
at a rate of 6.7% for both the 190mg naltrexone group
and placebo crowd, as compared to 14.1% in the 380mg
treatment group.
WHO
WILL IT BENEFIT?
Gender and intention to abstain before the trial were
two major factors that contributed to the success of
the naltrexone injections. Men were more positively
affected by the injections than women, although there
were too few women in the trial to determine why.
Participants who had abstained
from drinking for a week before starting the trial also
fared better in avoiding heavy drinking days. This trial
didn't pre-select participants who had already formed
the intention to quit drinking, which implies that those
who plan to get on the wagon may benefit from this treatment
even more than the trial results suggest.
"We are still learning how best
to use medications for alcoholism in a family practice
setting and will know a lot more in the next few years,"
says Dr Garbutt. "Until then, we have two relatively
new medications — acamprosate and naltrexone —
that should be strongly considered by family practitioners
as they treat alcoholism."
JAMA Apr 6 2005;293(13):1617-25
|
