The drug naltrexone is used in the U.S. for the treatment of alcohol dependence. The largest study of its effectiveness so far showed that it decreased the risk of a relapse into heavy drinking by around 36%. However, naltrexone also has a number of unpleasant side effects including nausea, dizziness and fatigue. Researchers from the University of Connecticut looked into the effectiveness of 'targeted' doses of naltrexone i.e. taking it when cravings were particularly strong or before 'triggering' situations. Half of the 163 people in the study took naltrexone daily and half took it on a targeted basis and within the two groups half of the participants were given a placebo. The men taking targeted naltrexone drank less drinks per day on average and both sexes taking targeted naltrexone dranks less drinks per drinking day.
Kranzler, Henry R. ... [et al] - Targeted naltrexone for problem drinkers Journal of Clinical Psychopharmacology August 2009, 29(4), 350-357