Acamprosate Review Concludes It's Effective

The most recent meta-analysis regard acamprosate concluded that it was safe and effective for treating alcohol dependence, with a number needed to treat (NNT) of 9 (9 patients have to be treated to prevent one relapse.) This NNT is quite acceptable. I remain skeptical, however. I'm going to look the paper over in more detail and weigh in with my own take.

MW

Medscape Medical News

Acamprosate May Be Helpful to Treat Alcohol Dependence

Laurie Barclay, MD


September 13, 2010 — Acamprosate appears to be effective and safe for supporting continuous abstinence after detoxification in alcohol-dependent patients, according to the results of a systematic review reported September 8 in the Cochrane Database of Systematic Reviews.

"Alcohol dependence is among the main leading health risk factors in most developed and developing countries," write Susanne Rösner, from the University of Munich in Munich, Germany, and colleagues. "Therapeutic success of psychosocial programs for relapse prevention is moderate, but could potentially be increased by an adjuvant treatment with the glutamate antagonist acamprosate."

To compare the efficacy and tolerability of acamprosate vs placebo or active control, the reviewers searched the Cochrane Drugs and Alcohol Group (CDAG) Specialized Register, PubMed, EMBASE, and CINAHL in January 2009. They also asked manufacturers and investigators for data from unpublished studies.

Inclusion criteria were double-blind, randomized controlled trials (RCTs) comparing drinking-related outcomes obtained with acamprosate vs those obtained with placebo or with other pharmacotherapy. Two authors independently extracted data; one author evaluated trial quality, and a second author verified this assessment. Primary efficacy outcomes were confirmed with use of meta-analyses of individual patient data.

There were 24 RCTs meeting selection criteria, enrolling a total of 6915 alcohol-dependent participants. Risk of any drinking was significantly lower with acamprosate vs placebo (relative risk [RR], 0.86; 95% confidence interval [CI], 0.81 - 0.91). The number needed to treat [NNT] to benefit was 9.09 (95% CI, 6.66 - 14.28), and cumulative abstinence duration MD was significantly higher (10.94; 95% CI, 5.08 - 16.81). However, gamma-glutamyltransferase (GGT) levels, heavy drinking, and other secondary outcomes did not reach statistical significance.

"Acamprosate is certainly no magic bullet, but it is a safe and effective treatment for patients who are trying to stop drinking," Dr. Rösner said in a news release. "The benefits we have seen in these trials are small. However, we must remember that these are additional benefits on top of those from other non-drug therapies."

The only adverse effect reported more frequently with acamprosate vs placebo was diarrhea (RD, 0.11; 95% CI, 0.09 - 0.13). The NNT to harm was 9.09 (95% CI, 7.69 - 11.11). Compared with nonprofit-funded trials, findings from industry-sponsored trials were not significantly different, and the linear regression test did not demonstrate any significant risk for publication bias (P = .861).

"Acamprosate appears to be an effective and safe treatment strategy for supporting continuous abstinence after detoxification in alcohol dependent patients," the study authors write. "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."

Limitations of this study include those inherent in the included trials, such as poor compliance with assigned study drug, as well as some heterogeneity between studies.

Three of the reviewed trials compared acamprosate vs naltrexone. These trials showed comparable effects of the 2 drugs on return to any drinking, return to heavy drinking, and cumulative abstinence duration.

"Patients' doubts and reservations against a strategy that uses one substance to treat dependency on another should be taken seriously, while interventions that have been shown to work should not kept back from patients," Dr. Rösner said.

The Federal Ministry of Education and Research supported this study.