From the FDA Drug Label
Buspirone has moderate affinity for brain D2-dopamine receptors. Possible Concerns Related to Buspirone's Binding to Dopamine Receptors Because buspirone can bind to central dopamine receptors, a question has been raised about its potential to cause acute and chronic changes in dopamine-mediated neurological function
Buspirone's effect on dopamine levels is not directly stated. However, it is known that buspirone binds to dopamine receptors, which may imply an indirect effect on dopamine levels. The clinical significance of this binding is not clear, and no conclusion can be drawn about its direct effect on dopamine levels. 1 1
From the Research
Buspar (buspirone) primarily affects serotonin receptors rather than dopamine receptors, with its most significant interaction being as a partial agonist at 5-HT1A serotonin receptors, as supported by the most recent and highest quality study 2. The medication's primary mechanism of action is not related to dopamine levels, but rather to its serotonergic activity. While Buspar does have some minimal interaction with dopamine D2 receptors, this effect is much weaker than its serotonergic activity and is not considered its primary mechanism of action, as noted in the study published in 2012 2. Unlike antipsychotic medications that strongly block dopamine receptors, Buspar doesn't significantly alter dopamine transmission in the brain, which explains why it doesn't cause movement disorders or other dopamine-related side effects commonly seen with antipsychotics. Some key points to consider when prescribing Buspar include:
- Starting doses: 5mg taken 2-3 times daily
- Gradually increasing to 20-30mg daily divided into multiple doses
- Time to reach full therapeutic effect: 2-4 weeks
- Efficacy for anxiety disorders, including generalized anxiety disorder with coexisting mild depressive symptoms, as demonstrated in a study published in 1996 3
- Lack of immediate anxiety relief, unlike benzodiazepines, and the importance of consistent use over time. It's essential to note that the evidence from the studies 4, 5, 6 supports the use of Buspar for anxiety disorders, but the most recent and highest quality study 2 provides the most relevant information on its mechanism of action and effects on dopamine levels.