RECENTLY APPROVED THERAPIES FOR PARKINSON'S
Many medications are available for the treatment of both motor and non-motor symptoms of Parkinson's. (Read more about these options on the Parkinson's Disease Medications Page.) A few of these drugs, which have gained approval in the last several years, are highlighted below. MJFF remains deeply committed to advancing the most promising research toward new and better symptomatic therapies as well as a disease-modifying treatment. (Learn more about therapies in development.)
MEDICATIONS FOR MOTOR SYMPTOMS
Extended-Release Amantadine (GOCOVRI)
Extended-release amantadine, which works on the dopamine and glutamate brain chemical pathways, became the first drug specifically indicated for levodopa-induced dyskinesia (irregular, involuntary, uncontrolled movements) in August 2017. The medication is a long acting reformulation of immediate-release amantadine, which has been available for many years. The extended-release capsules are intended to be taken once daily, at bedtime, so that drug levels are highest during the day, when dyskinesia typically is most prevalent.
In addition to lessening the severity and duration of dyskinesia, this drug also may decrease total daily "off" time (when symptoms are not well controlled because medication is not working optimally).
Many view once-a-day dosing as an advantage, especially if they require multiple daily doses of immediate-release amantadine or if they are on otherwise complex medication regimens.
Cons and Complications
The most common possible side effects include dizziness, low blood pressure (particularly when standing up), dry mouth, falls, hallucinations and leg swelling. In those with kidney problems, the dose needs to be adjusted.
Xadago (safinamide) was approved in 2017 as an add-on treatment for people with Parkinson's disease (PD) who are taking levodopa/carbidopa and experiencing "off" episodes. An "off" episode is when medication is not working well and Parkinson's symptoms — such as tremor, stiffness and slowness — return.
Xadago is taken once a day by mouth. It can be given at any point in the course of disease but since it's used in conjunction with levodopa when "off" episodes appear, it's typically added in the middle or later phases of PD.
This medication is classified as a monoamine oxidase B (MAO-B) inhibitor, which means that it blocks the normal activity of an enzyme — monoamine oxidase — that breaks down dopamine after it completes its activity in the brain. This allows the available dopamine (made by remaining dopamine-producing cells) to function for a longer period of time. Xadago also impacts glutamate, another brain chemical involved in the normal movement signaling pathway.
Xadago may increase the total daily amount of "on" time (when Parkinson's symptoms are controlled and medication is working well) and lessen total daily amount of "off" time (when symptoms are present).
Cons and Complications
Potential side effects include dyskinesia (uncontrolled involuntary movement), falls, nausea and insomnia. As with all MAO-B inhibitors, there is a risk of a rare, but potentially severe, reaction called "serotonin syndrome" when Xadago is taken with certain drugs. These include, but are not limited to, specific antidepressants, muscle relaxants and pain medications, as well as herbal supplements (e.g., St. John's Wort) and over-the-counter (OTC) cough or cold therapies, such as dextromethorphan. Serotonin syndrome is characterized by muscle rigidity, increased tremor and reflexes, high blood pressure and heart rate, sweating, diarrhea, fever, shivering, confusion and agitation.
When taken in high doses (not often prescribed for PD) and combined with large amounts of tyramine-containing foods (e.g., aged cheeses and cured meats), MAO-B inhibitors also could lead to "hypertensive crisis," which is significantly elevated blood pressure. This, too, is rare. Foods high in tyramine don't need to be eliminated from the diet, but should probably be eaten in moderation. (Learn more about MAO-B inhibitors and diet.)
Rytary was approved in 2015 for the management of Parkinson's motor symptoms. Rytary is a capsule that contains both immediate and extended-release forms of levodopa and carbidopa. (Levodopa gets converted in the brain to dopamine, the chemical that is missing in Parkinson's; carbidopa is a drug that helps levodopa get into the brain.) Rytary aims to ease the motor symptoms (tremor, stiffness, slowness) of Parkinson's. It can be taken at any stage of Parkinson's disease but is more commonly prescribed when people have inadequate symptom control or significant "off" time -- periods when medication isn't working optimally and symptoms return. Compared to other formulations of levodopa, such as Sinemet, the total daily amount required with Rytary is higher, but administration may be less frequent. In other words, more pills may be taken less often -- three to five times per day on average. Rytary starts to take effect in about 30 minutes and lasts approximately four to six hours, although this varies depending on the individual.
The extended-release part of Rytary may allow for fewer daily dosages and less "off" time. For those who have difficulty swallowing pills, the capsule can be opened and the medication sprinkled on applesauce or food of similar consistency for immediate consumption. Many researchers and specialists hope that by providing a more constant level of levodopa in the blood (and therefore in the brain) with medications like Rytary, long-term complications (such as dyskinesia) may potentially be lessened.
Cons and Complications
Possible side effects of Rytary are the same as those for other levodopa formulations. Nausea, low blood pressure (which can lead to dizziness and lightheadedness) and hallucinations are the most common. Dyskinesia (involuntary, uncontrolled movements) also may occur, though this might be lessened by adjusting the dose and/or timing of medication administration.
As with other preparations of levodopa, Rytary competes with dietary protein for absorption in the intestine. So, if it is not working optimally to control symptoms (wearing off before the next dose is due, taking a long time to kick in, etc.) doctors may recommend separating medication from high-protein meals by 30-60 minutes.
Duopa was approved in 2015 for the treatment of Parkinson's motor symptoms (tremor, slowness, stiffness). It is a gel formulation of carbidopa and immediate-release levodopa that is designed for continuous infusion directly into the small intestine, where levodopa is absorbed. (Read more about levodopa on the Parkinson's Medications Page.) This method of administration bypasses the stomach, which can empty slowly and irregularly in Parkinson's, leading to poor absorption and unpredictable effectiveness of oral medications. An external device (which can be worn during regular daily activities) pumps Duopa into the intestine through a surgically-implanted tube. Duopa is typically infused for 16 hours a day to maintain a steady level of levodopa in the blood and thereby lessen total daily "off" time. It is most often used in people who have motor complications (dyskinesia and/or significant "off" time -- when medication is not working optimally and symptoms return).
Duopa may be an alternative to deep brain stimulation (DBS) for people who either do not want to or cannot undergo the surgical procedure because of cognitive (memory and/or thinking) problems or other medical conditions. By providing a steadier level of levodopa in the blood (and brain), Duopa may lessen dyskinesia and "off" time.
Cons and Complications
The potential side effects of Duopa include those listed for other levodopa formulations: nausea, low blood pressure (with dizziness and lightheadedness), hallucinations, etc. However, the surgical tube required for administration involves additional risks -- infection, bleeding, clogging and/or dislodging. Duopa also may require increased assistance from a family member or caregiver to keep the tube clean and administer the medication.
Learn More about Duopa:
MEDICATIONS FOR NON-MOTOR SYMPTOMS
Northera (droxidopa) was approved in 2014 to treat orthostatic hypotension -- a decrease in blood pressure upon changing positions (standing from sitting, for example) that can cause dizziness, lightheadedness and/or passing out. In Parkinson's disease, orthostatic hypotension may occur as a result of the underlying disease and/or the medications used to treat it. Northera is converted to norepinephrine, a signaling chemical made naturally by the body, which works to raise blood pressure.
Northera can lessen dizziness and lightheadedness that result from low blood pressure. It may also prevent passing out and/or falls resulting from imbalance or instability caused by low blood pressure.
Cons and Complications
A potential side effect of Northera is high blood pressure while sitting or lying down, which is known as supine hypertension. Blood pressure should be checked in these positions prior to and after starting medication, as well as any time the dosage is adjusted. If nighttime blood pressure is elevated, raising the head of the bed and/or taking a medication to lower blood pressure during sleep may be necessary. Additional possible adverse effects of Northera include headache, dizziness and nausea.
Nuplazid (pimavanserin) was approved in 2016 for the treatment of hallucinations (usually visual -- seeing things that aren't there) and delusions (fixed, false, often paranoid, beliefs) due to Parkinson's disease psychosis. Nuplazid works on the serotonin brain chemical system to lessen symptoms of psychosis.
Nuplazid does not affect the dopamine pathway (as do most other antipsychotic drugs), and therefore it typically eases psychosis symptoms without worsening Parkinson's motor symptoms. Nuplazid also may improve nighttime sleep and daytime wakefulness, as well as decrease stress psychosis can place on a caregiver.
Cons and Complications
The most common side effects of Nuplazid are leg swelling, nausea and confusion. Like many antipsychotic medications, Nuplazid carries a "black box" warning of the potential for increased risk of death when used in elderly people who have dementia (significant memory and/or thinking disturbances). It's worth stating that untreated psychosis also can lead to considerable problems, so this medication should be considered when the potential benefits outweigh the possible risks.
Learn More About Nuplazid:
The medical information contained in this article is for general information purposes only. The Michael J. Fox Foundation has a policy of refraining from advocating, endorsing or promoting any drug therapy, course of treatment, or specific company or institution. It is crucial that care and treatment decisions related to Parkinson's disease and any other medical condition be made in consultation with a physician or other qualified medical professional.
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