Dopamine blockers and depletors are medications that prevent the body from using or producing the neurotransmitter dopamine. These drugs may be used to treat a number of health problems, including some neurological conditions. 

Dopamine is a neurotransmitter that helps regulate body movements and other motor and cognitive functions. In healthy bodies, neurons produce and release dopamine in the brain and other parts of the body. When the dopamine is released by one neuron, it is received by the receptors of the next neuron. This chain reaction eventually leads to the stimulation of nerves. 

Adequate amounts of dopamine in the brain help promote smooth, coordinated movement. Over-production or increased activity of dopamine can result in movement disorders, such as the characteristic chorea of Huntington's disease and the tics of Tourette syndrome. Inadequate levels or decreased activity of dopamine triggers symptoms such as tremor, rigidity and bradykinesia (slowness of movement).

Dopamine blockers and depletors are used to treat conditions that arise from the over-production or increased activity of dopamine. Dopamine blockers work by binding to and blocking the action of dopamine receptors. This prevents the receptors from using the dopamine that is present in the brain or elsewhere in the body. Conversely, dopamine depletors work by preventing dopamine from being stored or released by neurons.

There are numerous types of dopamine blockers and depletors. Some of the most common include pimozide (Orap), haloperidol (Haldol) and olanzapine (Zyprexa). Tetrabenazine is also a common medication as it acts as both a dopamine blocker and depletor.

Other examples of dopamine blockers and depletors include:

• chlorpromazine hydrochloride (Thorazine)
  
  
• domperidone
  
  
• droperidol (Inapsine)
  
  
• fluphenazine hydrochloride (Prolixin)
  
  
• metoclopramide (Reglan)
  
  
• perphenazine (Trilafon)
  
  
• prochlorperazine (Compazine)
  
  
• thiethylperazine (Torecan)
  
  
• trimethobenzamide (Tigan)
  
  
• reserpine (Serpalan)

Dopamine blockers and depletors are available in different forms, such as pill or injection. Some long-acting injections may last for up to six weeks.