Shared from myparkinsonsteam.com.
After Parkinson’s disease (PD), drug-induced parkinsonism (DIP) is the second most common cause of parkinsonism in the older population. “Parkinsonism” refers to a having a particular set of symptoms related to motor function. A movement disorder, DIP is often misdiagnosed as PD.
Unlike PD, however, DIP is caused exclusively by drugs that influence a chemical in the brain known as dopamine. It’s important to understand what might be behind the development of DIP and how it’s treated.
What Is Drug-Induced Parkinsonism?
The movement disorder DIP is a form of parkinsonism that begins as a side effect of using certain medications. These drugs typically block the chemical messenger known as dopamine. However, a person’s age also plays a role, because aging is associated with reductions in dopamine levels in the brain. Therefore, the combination of aging and medication use can make someone a prime target for DIP.
Being female can also be a risk factor, because the hormone estrogen suppresses the receptors that dopamine targets. When dopamine is suppressed or blocked by a drug in an at-risk person, their symptoms can mimic those caused by PD.
These parkinsonism-inducing drugs are usually antipsychotics. Other types of drugs, such as anti-nausea and selective serotonin reuptake inhibitor (SSRI) antidepressant medications, can influence DIP development as well.
The following drugs have been implicated in potentially causing DIP to develop:
- Antipsychotics (typical and atypical) — Haloperidol (formerly sold as Haldol), chlorpromazine (formerly sold as Thorazine), and risperidone (Risperdal)
- Anti-nausea medications — Metoclopramide (Reglan)
- Calcium channel blockers — Flunarizine and cinnarizine (not approved for use in the United States)
- Dopamine depleters — Reserpine (formerly sold as Serpasil) and tetrabenazine (Xenazine)
- Antidepressants — Fluoxetine (Prozac) and sertraline (Zoloft)