What are Other Medications to Treat Parkinson’s?

Parkinson’s disease (PD) is a chronic, progressive disease that affects the nerve cells in the body and the brain. PD causes a number of symptoms, both motor (affecting movement) and non-motor. While there is no known cure for PD, medications are available that can help manage the symptoms.

Initial therapy for motor symptoms of PD is usually levodopa (administered with carbidopa), dopamine agonists, and/or monoamine oxidase-B (MAO-B) inhibitors. The combination of levodopa and carbidopa is the most effective treatment available for the management of motor symptoms of PD. However, it can cause a side effect known as dyskinesia, abnormal involuntary movements. Dopamine agonists are less effective on the motor symptoms of PD but have a lower rate of causing dyskinesia, although they have other side effects. MAO-B inhibitors are less effective than levodopa or dopamine agonists; however, they have fewer side effects. Treatment is customized to the individual person, based on their symptoms and with an understanding of the risks and benefits of each class of medication.1

In addition to the previously mentioned classes of medication that are used to treat the motor symptoms, there are several other medications that may be used in the treatment of PD, including medications which treat specific symptoms, including dementia, hallucinations, delusions, tremor, or orthostatic hypotension (a falling of blood pressure that occurs upon changing positions or standing).2

ProAmatine® (midodrine hydrochloride)

ProAmatine® is a prescription medication used to treat orthostatic hypotension, a falling of blood pressure that occurs upon changing positions or standing. Orthostatic hypotension is one of the symptoms caused by PD. Orthostatic hypotension can cause dizziness, lightheadedness, and a faint feeling.2,4

Midodrine hydrochloride tablets should be prescribed in patients whose lives are considerably impaired despite standard clinical care, including non-pharmacologic treatment (such as support stockings), fluid expansion, and lifestyle alterations. Once prescribed and the patient starts taking the medication, midodrine hydrochloride tablets should be continued only for patients who report significant symptomatic improvement.11

As with any prescription medication, ProAmatine tablets may cause side effects. The most common side effects experienced by people talking ProAmatine include paresthesia (tingling, prickling, numbing, chilling, or burning sensation of the skin), piloerection, painful or difficult urination, severe itching of the skin, chills, pain, and rash. The most potentially serious side effect associated with ProAmatine is supine hypertension, which can cause complications when treating a patient for orthostatic hypotension.11

Northera® (droxidopa)

Northera® is another prescription medication used to treat orthostatic hypotension.

The effectiveness of Northera beyond two weeks of treatment has not been established through clinical trials, and continuing treatment with Northera after two weeks is determined by a healthcare professional and dependent on the individual person’s needs.

The exact mechanism of action of Northera is not known, but scientists believe that droxidopa, the active compound in Northera, is converted to norepinephrine in the body. Norepinephrine is a neurotransmitter, or chemical messenger, that helps regulate blood pressure, among other things.

As with any prescription medication, Northera may cause side effects. The most common side effects experienced by people taking Northera include headache, dizziness, nausea, high blood pressure, and being tired. Although Northera is used to raise low blood pressure experienced in orthostatic hypotension, raising blood pressure too much results in hypertension (high blood pressure), which can be dangerous and may increase the risk of cardiovascular events, like stroke and heart attack. People taking Northera should regularly monitor their blood pressure, especially when the dosage is increased.

Nuplazid™ (pimavanserin)

Nuplazid™ is a prescription medication that is used to treat hallucinations and delusions associated with Parkinson’s disease (PD). More than half of all people with PD will develop hallucinations or delusions during the course of their disease. These symptoms greatly affect the quality of life for both people with PD and their caregivers and are associated with an increased incidence of nursing home placement and an increased risk of death. In clinical trials, Nuplazid significantly reduced the number and severity of hallucinations and delusions in people with PD psychosis.5,6

The exact mechanism of action of Nuplazid is not known, but scientists believe that pimavanserin, the active compound in Nuplazid, interacts with the serotonin receptors. Serotonin is a neurotransmitter, or chemical messenger, that helps regulate mood and other bodily functions. Since Nuplazid does not interact with dopamine, it is safer in people with PD.

Exelon® (rivastigmine tartrate)

Exelon and Exelon® Patch (rivastigmine transdermal system) are prescription medications used to treat mild, moderate, and severe memory problems associated with Parkinson’s disease (PD). Exelon is the first treatment approved by the U.S. Food and Drug Administration (FDA) for the treatment of dementia from PD. Exelon is also used to treat dementia from Alzheimer’s disease.7,8

Although the precise mechanism of action of Exelon is not known, scientists believe that rivastigmine, the active compound in Exelon, enhances cholinergic function. Cholinergic neurons are those nerve cells that produce acetylcholine, a neurotransmitter (chemical messenger) that has many roles in the brain and body, including in the function of memory.1,6

As with any prescription medication, Exelon may cause side effects. The most common side effects experienced by people taking Exelon include nausea, vomiting, loss of appetite, indigestion, and muscle weakness. The most common side effects experienced by people taking Exelon Patch include depression, headache, anxiety, dizziness, stomach pain, urinary tract infections, muscle weakness, tiredness, and trouble sleeping.1,6

Nuedexta® (dextromethorphan HBr and quinidine sulfate)

Nuedexta is a prescription medication for the treatment of PseudoBulbar Affect (PBA), a condition that can affect people with PD and is characterized by sudden, uncontrollable outbursts of crying or laughing. In people with PBA, the involuntary emotional responses do not match the person’s feelings, and the outbursts can be intense or occur during inappropriate times.9

While the exact mechanism of action is not fully understood, the two medicines (dextromethorphan and quinidine) in Nuedexta have demonstrated effectiveness in reducing PBA episodes in clinical trials. The reduction increased as patients stayed on the drug longer, with an average 44% reduction seen in the first week of treatment and an average 82% reduction seen after 12 weeks of treatment.9,10

Common side effects experienced by patients taking Nuedexta in clinical trials include diarrhea, dizziness, cough, vomiting, weakness, swelling of the feet or ankles, urinary tract infection, flu, and flatulence (gas).9,10

Amantadine

Amantadine is a medication that used to treat some symptoms of Parkinson’s disease (PD), including tremors and dyskinesias. Amantadine is an anti-viral medication that also seems to act as a weak NMDA receptor antagonist. While the exact way amantadine works isn’t fully understood, scientists believe that it increases the amount of dopamine in the brain.3,12,13 There are three different formulations of amantadine available:

  • Symmetrel® (amantadine), which is used to help with tremor
  • Gocovri™ (amantadine), which can treat dyskinesia in people with PD who are receiving levodopa therapy with or without additional dopaminergic medications
  • Osmolex ER™ (amantadine), which can treat PD and extrapyramidal symptoms from other medications

Each medication has its own set of possible side effects:

  • Common side effects of Symmetrel include dizziness, weakness, dry mouth, constipation, blurry vision, skin blotches, impaired mental acuity, or orthostatic hypotension (falling blood pressure upon standing).3
  • The most commonly experienced side effects by patients taking Gocovri in clinical trials were hallucination (seeing or hearing things that aren’t there), dizziness, dry mouth, swelling of the legs or feet (peripheral edema), constipation, falling, and orthostatic hypotension, the sudden lowering of blood pressure upon standing.12
  • Osmolex may cause side effects such as nausea, dizziness or lightheadedness, and difficulty sleeping (insomnia). Osmolex may increase the risk of falling asleep during normal activities and may increase symptoms of depression or suicidal behavior.14

Treatments for other non-motor symptoms of Parkinson’s

Treatments of the non-motor symptoms are specific to the symptoms experienced. Some of the non-motor symptoms, such as constipation, certain sleep problems, psychotic symptoms, or impulsive behaviors, may be caused as a side effect of medications used to treat the motor symptoms of PD.

Other non-motor symptoms have both pharmacological and other therapy strategies that can help. For example, among the non-motor symptoms, there are medications that can work to reduce over-activity of the bladder in people who experience urinary problems, and pain may be relieved through a combination of medication, physical therapy, and exercise. Complementary therapies, such as acupuncture or massage, may also help relieve non-motor symptoms of PD.3

Because treatments for some of the non-motor functions can interact with PD treatments and cause unwanted or dangerous side effects, it is critical that the patient see a neurologist, particularly a movement disorders specialist who is specially trained in understanding how these drugs can affect a PD patient. It is also important to talk with your healthcare provider before starting or stopping any new treatments, including over-the-counter medications and alternative treatments.

Written by: Emily Downward | Last reviewed: November 2018
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