Background: Methamphetamine (MA) use disorders are major public health problems nationally and worldwide and treatment remains an unmet need.
Objectives: (1) To review preclinical and clinical studies identifying the dopamine D3 receptor as a therapeutic target for substance use disorders (SUDs), including MA dependence, (2) to consider buspirone (Buspar®) as a potential medication based on its dopamine D3 receptor antagonist properties, and (3) to evaluate the safety and initial efficacy of buspirone in a pilot study of MA-dependent individuals.
Methods: Literature on the dopamine D3 receptor as a therapeutic target and on the potential of buspirone as a novel therapy for MA dependence was reviewed. The cardiovascular and subjective effects of intravenous MA challenge were assessed in five non-treatment seeking individuals. Participants met DSM-IV criteria for MA dependence and were treated subacutely (9 days) with buspirone (60 mg daily).
Results: The literature identified the dopamine D3 receptor as a therapeutic target for MA dependence, a safe and approved medication, and a valuable opportunity to re-purpose buspirone for treating MA dependence and perhaps other SUDs. Pilot data (n = 5) indicated that buspirone is safe in MA-using individuals and comparison against historical placebo data from this laboratory suggested that at least some aspects of the subjective properties of MA may be diminished during buspirone treatment.
Conclusion: Future studies should include a small-scale, placebo-controlled Phase IIa trial of buspirone in MA dependence.