Parkinson's disease is a neurodegenerative disease affecting the substantia nigra, a component of the basal ganglia. The substantia nigra has a high quantity of dopaminergic neurons, which are neurons that release the neurotransmitter known as dopamine. When dopamine is released, it may activate dopamine receptors in the striatum, which is another component of the basal ganglia. When neurons of the substantia nigra deteriorate in Parkinson's disease, the striatum no longer receives dopamine signals. As a result, the basal ganglia can no longer regulate body movement effectively and motor function becomes impaired.
By acting as an agonist to the dopamine receptors, pramipexole may directly stimulate dopamine receptors in the striatum, thereby restoring the dopamine signals needed for proper functioning of the basal ganglia. Any depressant effects are most likely the result of pramipexole binding to the D2 receptor subtype, which exhibits inhibitory behavior.
Pramipexole binds to dopamine receptors, with particularly high affinity for the D3 receptor subtype.
Several unusual adverse effects of this medication may include compulsive gambling, hypersexuality, and overeating. These side effects may be linked to the D3 receptor agonist activity of pramipexole. D3 receptors are located in brain regions involved in mood, behavior, and rewards.