Dopamine is a neurotransmitter, or brain chemical, which regulates many physical and emotional processes. Some health disorders involve too low or too high levels of dopamine activity, explain scientists at the Addiction Science Research and Education Center at the University of Texas. A dopamine antagonist, also called a dopamine receptor antagonist, is a useful medication for people with an overactive dopamine system.
Dopamine Function
Proper levels of dopamine are essential for mental and physical health, according to the University of Texas website. This neurotransmitter is involved in the control of physical movement, emotional responses, behavior and the experience of pleasure and pain. Excessive dopamine activity can cause severe mental illness and physical symptoms.
Medication for Dopamine Levels
People with excessively low levels of dopamine need a medication called a dopamine agonist. Patients with Parkinson's disease, for instance, have nearly no dopamine in their brains, and they take medication to increase dopamine. Dopamine agonists attach to and stimulate dopamine receptors. A dopamine antagonist, in contrast, blocks dopamine receptors in the brain, preventing dopamine from attaching to these receptors.
Central Dopamine Antagonist Benefits
Dopamine antagonists have a significant role in treating schizophrenia and other serious mental disorders, according to an article on the University of Texas website. Lowering dopamine activity in people with an overactive dopamine system can alleviate most of their symptoms. The types of dopamine antagonists used for treating mental illness are central dopamine antagonists known as neuroleptics or antipsychotics, explains Pharmacorama. They include phenothiazines, butyrophenones, benzamides, atypical neuroleptics and long-action neuroleptics. In addition, these medications are very effective for treating migraine headaches, according to a study published in the June 1, 2005 issue of "Internal Medicine News."
Peripheral Dopamine Antagonist Benefits
The other type of dopamine antagonist has peripheral rather than central effects. These drugs can be used to increase gastric emptying of food, which decreases digestive symptoms such as nausea, vomiting and heartburn. The drug domperidone, for instance, is indicated for patients with Parkinson's disease who develop nausea due to their medication, according to the University of Pittsburgh Medical Center website. Another dopamine antagonist, metoclopramide, is sometimes used for short-term treatment of gastroesophageal reflux disease.
Considerations
Dopamine antagonists are associated with many side effects, some severe, particularly when patients use them for long periods of time. Except in the case of psychotic disorders, these drugs are typically only used on a short-term basis, according to Pharmacorama.com. Dopamine antagonists can cause sedation and drowsiness, confusion, passivity, constipation and weight gain. If taken for a long time, they can lead to a condition called tardive dyskinesia, which involves unintentional facial and muscle movements. The drugs can also cause pseudo-Parkinsonism, in which the patient is unable to stay motionless. In addition, long-term use of these medications is linked to severe cardiovascular issues.
