The National Institutes of Health (NIH) states that certain antipsychotics can cause Parkinson-like symptoms, which is also called secondary parkinsonism. The side effects stem from the drugs interfering with dopamine in the brain: Parkinson's disease is caused by a lack of dopamine due to cell damage. Antipsychotics that block dopamine are used to treat disorders that are caused by too much dopamine, like schizophrenia, according to "Psychiatric Disorders." Secondary parkinsonism from antipsychotics are temporary, since the symptoms stop after the medication is ceased.
Antipsychotics Involved
Not all antipsychotics result in Parkinson-like side effects. The National Parkinson Foundation states that three types of antipsychotics can cause these symptoms: dopamine receptor blocking agents, dopamine depleting agents and atypical antipsychotic drugs. Dopamine receptor blocking agents affect the levels of dopamine in the brain by preventing the neurotransmitter from binding to its appropriate receptor; examples are phenothiazines, butyrophenones and metoclopramide. Dopamine-depleting agents break down the neurotransmitter so it cannot be used; reserpine and tetrabenazine are both examples. The last group of drugs that can cause secondary parkinsonism is atypical antipsychotic drugs, though the exact mechanism is unknown.
Symptoms
The symptoms of secondary parkinsonism from antipsychotics are similar to Parkinson's disease: because of the lack of dopamine, communication is disrupted between the brain and muscles, resulting in mobility problems. The patient can have tremors and problems starting or controlling his movements, according to the NIH. Stiffness may also be experienced, as well as partial paralysis. The patient can also have decreased facial experiences and a softer voice.
Appearance of Symptoms
The National Parkinson Foundation states that not all patients who take these antipsychotics will develop Parkinson-like symptoms---it depends on the potency and dosage of the drug. The symptoms can begin within a few days of taking the antipsychotic, and will last until the patient discontinues the drug. While symptoms cease within a few weeks after the patient stops using the medication, symptoms may continue for months or even years in elderly patients.
Member Comments