Patterns of dispensed disulfiram and naltrexone for alcoholism treatment in a veteran patient population.

Background: Short-term treatment trials indicate that two Food and Drug Administration-approved agents, disulfiram and naltrexone, may each curtail alcohol consumption, but two large 1-year Veterans Administration cooperative studies showed no long-term benefits for these agents over placebo. To assess whether these agents are being prescribed for extended periods, as an indicator of long-term use in nonexperimental settings, we compared dispensing patterns in a veteran patient population.

Methods: The New England Veterans Integrated Service Network outpatient pharmacy files between January 1, 1998, and June 30, 2001, were analyzed; only patients with prescriptions on or after March 1, 1998, were included. Measurements for each patient included data on new and refilled prescriptions of disulfiram, naltrexone, and control medications. Prescription survival curves with right censoring were constructed. Distinct treatment episodes were defined by having six or more months between the end date of a prior prescription and the start date of a new prescription.

Results: From eight New England Veterans Integrated Service Network centers, 754 patients were dispensed disulfiram, and 971 were dispensed naltrexone, encompassing 873 and 1075 treatment episodes, respectively. Treatment episode durations were virtually identical for both drugs: more than 35% of episodes were 1 month or shorter, more than 50% were 2 months or shorter, and 75% were 5 months or shorter. Concurrently prescribed neuroleptic or statin medications predicted longer disulfiram and naltrexone treatment episodes. However, for patients newly prescribed common neuroleptic, antidepressant, or statin agents, the risks for discontinuing disulfiram or naltrexone were 1.4 to 2.3 times greater than for discontinuing these other agents.

Conclusions: In clinical settings, veteran patients were likely to be dispensed either disulfiram or naltrexone for only several months or less. The contexts and reasons for these predominantly short-term treatment episodes or the benefits derived were not known and merit further study.