Parkinson's disease is a progressive neurologic disorder where the cells in a section of the brain called the substantia nigra degenerate, according to the Muhammad Ali Parkinson Center and Movement Disorders Clinic. This degeneration causes a decrease in the substance dopamine which affects motor skills and speech. The causes of Parkinson's disease are not fully understood, but there are certain medications that can cause drug-induced Parkinson disorders, which present with the symptoms of Parkinson's. Many of these medications have the ability to block the dopamine receptors or affect the levels of dopamine in the brain; the better the medication is at affecting dopamine levels, the more likely it is to cause Parkinson's symptoms, according an article on the PD Caregiver website.
Phenothiazines
Phenothiazines are medications that are dopamine-blocking agents, according to the PD caregiver website. These medications can be used to treat mental disorders, anxiety and nausea depending on the medicine according to MayoClinic.com. Patients taking these medications may develop secondary Parkinson's symptoms like uncontrolled movements of the mouth, jaw, arms or legs, which may or may not go away after the medication is discontinued; children and elderly adults are at higher risk of developing side effects than younger adults. Examples of phenothiazine medications are chlorpromazine which is sold as Thorazine, prochlorperazine, sold as Compazine and thioridazine, which is also sold as Mellaril.
Butyrophenones
Butyrophenones are another class of medications that can cause drug-induced Parkinson disorders; these medications are dopamine blockers, as well, as noted on the PD Caregiver website, and can also cause movement disorders. An example of this class of medication is haloperidol, or Haldol, which is used for patients with schizophrenia.
Dopamine-Depleting Agents
Medications that lower the levels of dopamine can also cause Parkinson's symptoms, according to the PD Caregiver's website. Interestingly, these medications are often used to treat movement disorders in some patients, according to WeMove.org. Tetrabenazine is a commonly used dopamine-depleting agent; other agents like reserpine as less commonly used.
Metoclopramide
Metoclopramide as known as Reglan is another dopamine-blocker medication that can cause Parkinson's-like symptoms, as noted on the PD Caregiver website. Physicians prescribe this medication for patients with diabetes who have a certain type of stomach disorder called gastroparesis, according to MayoClinic.com; this medication can also treat nausea. If a patient notices the development of any uncontrolled movements, his physician should be alerted right away.
