Drug May Improve Abstinence in Alcoholics
September 10, 2010
By Crystal Phend, Senior Staff Writer,
Reviewed by Zalman S. Agus, MD; Emeritus Professor, University of Pennsylvania School of Medicine and
Dorothy Caputo, MA, RN, BC-ADM, CDE, Nurse Planner
Alcoholic patients can modestly improve their chances of staying abstinent after detox with acamprosate (Campral), according to a Cochrane review.
The glutamate antagonist significantly reduced the risk of return to any drinking compared with placebo (relative risk 0.86, 95% confidence interval 0.81 to 0.91), Susanne Rösner, PhD, of the Psychiatric Hospital at the University of Munich, Germany, and colleagues found.
The number needed to treat to prevent relapse in one patient was 9.09 when added to psychosocial treatment, they reported in the Cochrane Library.
"Even though the sizes of treatment effects appear to be rather moderate in their magnitude, they should be valued against the background of the relapsing nature of alcoholism and the limited therapeutic options currently available for its treatment," they wrote in the review.
¦Note that acamprosate was used as an adjunctive therapy to psychosocial interventions. Thus, effect sizes reflect the additional benefit of adding acamprosate to these treatments rather than its benefit compared with placebo alone.
¦Note that the authors indicate that even though the positive effects are moderate, they should be considered significant considering the limited therapeutic options available and the frequent relapses typically associated with alcoholism.
Acamprosate is one of three agents, along with disulfiram (Antabuse) and the opioid antagonist naltrexone (ReVia), approved in the U.S. for treating alcohol dependence.
The three trials included in the review comparing acamprosate to naltrexone showed similar effects on return to any drinking, return to heavy drinking, and cumulative abstinence duration.
The combined effect of the two drugs, while more substantial with a 30% reduced risk of return to any drinking, was not significant compared with placebo and nearly quadrupled the likelihood of dropping out due to side effects.
Either way, the evidence remains too sparse to draw final conclusions, the researchers cautioned.
No comparisons between acamprosate and disulfiram were found.
The review encompassed a total of 24 double-blind randomized controlled trials comparing the effects of acamprosate with placebo or active control on drinking-related outcomes in a 6,915 participants.
These patients received outpatient treatment in all but one trial, which involved adolescent inpatients. The participants were predominantly men with a median age 42 years.
Most of the studies were conducted in Europe, but two occurred in the U.S. and one each happened in South Korea, Australia, and Brazil.
All but one of the trials required detoxification before starting treatment. All included some form of concurrent psychosocial treatment, whether center-specific or encouraged participation in Alcoholics Anonymous (AA) groups.
When compared with placebo, acamprosate significantly increased the cumulative duration of alcohol abstinence during the trials by 11% (mean difference 10.94, 95% CI 5.08 to 16.81).
This effect persisted after treatment with a 9% lower risk of return to any drinking three to 12 months later (relative risk 0.91, 95% CI 0.87 to 0.96) and a 9% higher continuous abstinence duration at that point as well.
However, the drug didn't appear to significantly impact risk of a return to heavy drinking compared with placebo (relative risk 0.99, 95% CI 0.94 to 1.04).
Nor was there an effect on levels of the enzyme gamma-glutamyl transferase (GGT) used as a marker of liver health and alcohol intake.
The only side effect significantly boosted by acamprosate was diarrhea with a number needed to treat to cause an additional case of diarrhea that was the same as the number needed to treat to benefit -- 9.09.
The researchers cautioned about the low levels of medication compliance and high dropout rates in addiction treatment that likely were a factor in the trials as well.
Moreover, acamprosate's effects reflected adjunctive treatment on top of psychosocial treatment, they noted.
"All in all, acamprosate does not appear to be a magic bullet in the treatment of alcohol dependence and -- considering the complexity of processes involved in the development and maintenance of addiction -- there will probably never be a single strategy that can 'cure' alcohol dependence," Rösner's group concluded in the paper.
The review was supported by a grant from the German Federal Ministry of Education and Research.
Rösner reported having no conflicts of interest to declare. Several of the co-authors reported conflicts of interests with pharmaceutical companies including sanofi-aventis, Bristol-Myers Squibb, Eli Lilly, Janssen/Johnson and Johnson, Lundbeck, Merck, Pfizer, Lipha Pharmaceuticals, Forest Laboratories, Essex Pharma, Prempharm, and AstraZeneca.
Primary source: Cochrane Database of Systematic Reviews
Source reference: Rösner S, et al "Acamprosate for alcohol dependence" Cochrane Database of Syst Rev 2010; 9: CD004332.