Naltrexone appears to be an effective and safe strategy in alcoholism treatment. Even though the sizes of treatment effects might appear moderate in their magnitudes, these should be valued against the background of the relapsing nature of alcoholism and the limited therapeutic options currently available for its treatment.
A pilot evaluation of the safety and tolerability of repeat dose administration of long-acting injectable naltrexone (Vivitrex) in patients with alcohol dependence.
: Oral naltrexone is currently used as part of a treatment regimen for alcohol-dependent patients, but its clinical utility is hampered by poor patient adherence. A long-acting injectable naltrexone formulation (Vivitrex) was designed to facilitate patient adherence by providing an extended duration of therapeutic naltrexone over 1 month, thereby eliminating the need for daily dosing.
                : A multicenter, randomized, double-blind, placebo-controlled pilot study was conducted to evaluate the safety and tolerability of intramuscular repeat dose administration of this extended-release naltrexone formulation in DSM-IV alcohol-dependent patients. Thirty patients were randomized to treatment with injectable naltrexone (400 mg; n = 25) or a matching placebo injection (n = 5) and were dosed once every 28 days over 4 months. Psychosocial treatment was offered to patients in both treatment groups. Outcome measures related to drinking activity and trough plasma concentrations of naltrexone and its primary metabolite, 6-beta-naltrexol, were evaluated.
                : Injectable naltrexone was generally safe and well tolerated. Reported adverse events were mild to moderate and resolved without intervention; only two patients discontinued due to adverse events. The most common adverse events (nausea and headache) occurred at a similar rate for patients in both treatment groups. Pharmacokinetic analysis confirmed that therapeutic levels of naltrexone were delivered throughout the four 1-month treatment cycles.
                : The results of this pilot study provide the basis and methods for a larger, more definitive trial to determine the utility of this long-acting injectable naltrexone formulation in the treatment of alcohol-dependent patients.