Campral comes as a 333-mg enteric-coated tablet with weight mediated dosages of 2 tablets tds for adults over 60 kgs. and 2 tablets mane, 1 midday and 1 nocte for adults 60 kgs or less for at least one year. The dosage should be maintained if the patient relapses.

Controlled studies show that relapse rates in alcoholism are lower in acamprosate-treated patients than in patients treated with placebos. At one year, abstinence rates are about 19% in acamprosate-treated patients versus 8-9% in placebo treated subjects. At two years, the rates of abstinence are apparently 12% and 5% respectively. However, complete abstinence may not be the only goal to aim for with some patients.

Sass 1 found that 39% of acamprosate patients remained abstinent compared with 17% in their control group. In a double-blind multicentre study 2 with 569 patients, acamprosate 1.3 gram/day was more effective than placebo in maintaining alcohol abstinence for three months as assessed by plasma gamma-glutymyl transpeptidase. Whilst there was a significant decrease in both groups it was 32% lower in the acamprosate group than in the placebo group on day 60 and day 90.

Acamprosate 2g/day or 1.3g/day for 12 months was more effective than placebo in maintaining alcohol abstinence in another double-blind study 3 with 538 patients. Patients were assessed every three months and received supportive psychotherapy, antidepressants anxiolytics and continued any maintenance medication. Acamprosate was better than placebo in maintaining continuous abstinence at 12 months: 18.1 % of the 1.3 g/day group, 19.1% of the 2 g/day group, and 11.3% of the placebo group had been continuously abstinent. During the treatment period, the average number of days of continuous abstinence was significantly higher in the high-dose acamprosate group than in the placebo group with the average time to first relapse being 135 days, 153 days and 102 days respectively. At 12 months 28%, 35% and 19% respectively of patients were abstinent.

Alcohol consumption by patients who were abstinent at the 12-month follow up but who drank during the 12-month period was less frequent in the acamprosate groups. However, the abstinence rate was no longer significant 6 months after the treatment period.

Acamprosate was again found to be more effective than placebo in maintaining abstinence from alcohol in a multicentre placebo-controlled study 4 of 179 patients who completed the 12 months of treatment. At the end of the 360-day treatment period 18.3% of acamprosate and 7.1% of placebo patients had been continuously abstinent. The mean cumulative abstinence duration was also significantly greater in the acamprosate group than in the placebo group (138 Vs 119 days respectively). Of the 148 patients who completed the 12-month follow-up after the treatment period, 11.9% and 4.9% respectively were continuously abstinent at the end of the two-year study. The cumulative abstinence duration was significant for the entire two year study (acamprosate group = 230.8 days and placebo group = 183 days).

Poldrugo 5 also found that acamprosate treatment for alcoholism resulted in longer time to first relapse and a greater cumulative duration of abstinence than did the placebo treatment. 246 free-living were given a six months supply of either acamprosate or placebo and they reported to alcoholism treatment centres for assessment after 1,3,6,9, and 12 months. A significantly greater proportion of acamprosate subjects was abstinent at 1,3, and 6 months (the treatment period). The mean time to first relapse was 150 days for the acamprosate group and 61 days for the placebo group. During the 6 months' follow-up after cessation of treatment, the abstinence level declined in both groups but remained significantly higher for the acamprosate group at 1 year. The only side-effect detected in acamprosate treatment was diarrhoea, which occurred in about 20% of the acamprosate and in 12% of the placebo group for the first 7 days. 6

Mann 7 concurs with the above studies and concludes that although existing treatments (e.g. AA, therapeutic communities, counselling, etc) are often highly efficient, they reach few of the patients in need. GPs may come to play an especially important role in future therapy programs, provided they have the tools necessary for assessing and diagnosing (eg. CAGE - see GPSpeak, December 99 and motivational interviewing - see GPSpeak, October 99) and treating alcohol dependent patients. One such tool could be this drug that appears to reduce craving for alcohol and enhances abstinence.

As of November 1, 1999, Campral became available in Australia as a PBS listed item (authority required). The PBS listing states: "Authority required; for use within a comprehensive treatment program for alcohol dependence with the goal of maintaining abstinence." Maximum quantity 180 tablets with 1 repeat. PBS price $171.59.

Acamprosate appears to have a safe profile with two contraindications for use being renal dysfunction and severe liver failure. There is no experience of its use in pregnancy and as it passes into breast milk, it is not recommended for use in either of these situations. Naltrexone is likely to be more acceptable to patients with its once a day dosing, whereas acamprosate is based on weight and thrice daily dosing.

References:

1. Sass, H, Soyka, M, Mann, K, et al, 1996. Relapse Prevention by Acamprosate; results from a placebo-controlled study on alcohol dependence. (PRAMA study). Archives of General Psychiatry, 53:673-80.

2. Lhuintre, JP, Moore, ND, Tran, G, et al, 1990. Acamprosate Appears to Decrease Alcohol Intake in Weaned Alcoholics. Alcohol Alcohol, 25:613-22.

3. Paille, FM, Guelfi, JD, Perkins, AC, et al, 1995. Double-blind Randomized Multicentre Trial of Acamprosate in Maintaining Abstinence from Alcohol. Alcohol Alcohol, 30:239-47.

4. Whitworth, AB, Fischer, F, Lesch, OM, et al, 1996. Comparison of Acamprosate and Placebo in Long-term Treatment of Alcohol Dependence. Lancet, 347:1438-42.

5. Poldrugo, F, 1997. Acamprosate Treatment in a Long-term Community-based Alcohol Rehabilitation Program. Addiction, 92:1537-46.

6. Whitworth, AB, Fischer, F, Lesch, OM, et al, 1996. Comparison of Acamprosate and Placebo in Long-term Treatment of Alcohol Dependence. Lancet, 347:1438-42.

7. Mann, K, 1996. The Pharmacological Treatment of Alcohol Dependence: needs and possibilities. Alcohol & Alcoholism, 31(1): 55-58.