Patients should seek a medication review at least annually
By Karen Hales, Neurology Solutions Contributing Writer
There have been several exciting recent developments in the realization of advanced treatment options and new medications for Parkinson’s disease. From surgical treatments to drug development to a pump that infuses medication to patients throughout the day, individuals with Parkinson’s disease may benefit from the latest developments for treatment of PD.
Most patients with Parkinson’s disease can be adequately treated the first several years after the disease has begun presenting symptoms with medications that deliver levodopa, used alone or in combination with carbidopa. Later in the disease, individuals with PD may consider highly effective surgical treatments such as Deep Brain Stimulation and/or other medications or combinations of medications to manage their symptoms.
Trey Eskew, a physician’s assistant who has treated patients at Neurology Solutions Movement Disorders for the past six years, said that many patients aren’t aware of the new PD medications that have become available, including several that were released in 2015.
Neurology Solutions often prescribes a customized combination of medications that allows patients to keep their levodopa/carbidopa prescription, such as Sinemet, low and their symptoms well controlled. “Sometimes we’ll see a patient for the first time who has been taking Sinemet only for the past five or six years, and they don’t realize there are other ‘helper’ medications available with fewer side effects that can make Sinemet more effective,” Eskew added.
Patients should seek a medication review at least annually to ensure they are taking advantage of the latest most effective treatments for managing symptoms. As part of the review, your neurologist or movement disorder specialist should cross reference certain medications with any other prescriptions used to treat your individual medical conditions, as well as assess the prevalence of side effects, off-time, memory problems, and psychological symptoms such as depression, psychosis and impulse control issues.
Here are some facts and findings about the latest PD medications.
What are the most common drugs used to treat Parkinson’s Disease?
Developed in the late 1960s, levodopa was the first medication proven effective in treating a chronic neurological condition such as Parkinson’s and remains the single most effective agent in the treatment of PD. Levodopa is absorbed in the blood from the small intestine and travels through the blood to the brain, where it is converted into dopamine. A levodopa-enhancer, carbidopa enables a much lower dose of levodopa, reducing the dosage by almost 80 percent.
Sinemet is a carbidopa/levodopa therapy prescription typically prescribed to individuals with PD. Levodopa is converted by enzymes in the brain to produce dopamine, which helps neuron function in the brain responsible for movement. Prescribed levodopa often causes nausea and vomiting, but these side effects are lessened with the combination of carbidopa.
There are two forms of Sinemet, controlled-release (CR) and immediate-release Sinemet. While both are equally effective in treating symptoms of Parkinson’s disease, some people prefer the controlled release version, which can last as much as five hours, over the immediate version, which lasts in the body approximately 3-4 hours.
Rytary® is the most recently approved extended-release medication for the treatment of PD. Rytary was released in the first quarter of 2015, and NSC has been prescribing this new capsule formulation of carbidopa-levodopa to patients for approximately one year. In that time, the practice has found Rytary generally superior to Sinemet. Rytary can last as long as eight hours and reduce medication “off time,” the period when a person has greater difficulty with movement due to the medication wearing off, and side effects, such as nausea, and dyskinesia. Rytary can be quite expensive, depending on your insurance; however most doctor’s offices have samples to try this medication.
Azilect® (brand name) and Selegiline (generic) are MAO inhibitors that limit the breakdown of dopamine so that it can remain in the system longer. These drugs block an enzyme in the brain that breaks down levodopa. Studies have shown that Azilect can slow the progression of PD.
Levodopa is often the drug of choice to reduce the symptoms of PD; however the erratic muscle movement in Parkinson’s patients’ digestive systems can complicate getting the treatment into the bloodstream. Approved in January 2015 for patients with advanced Parkinson’s, DUOPA™, developed by AbbVie, delivers a levodopa-carbidopa intestinal gel directly to the small intestine via an infusion pump. It is meant to provide 16 hours of relief from symptoms, according to AbbVie, and over a 12-week period was shown to work better than immediate-release combinations of carbidopa and levodopa.
Levodopa/Carbidopa Treatments Under Development
Neuroderm is testing a still-unapproved version of the two drugs that would be administered via a transdermal patch. Also in the trial stages are Civitas’ inhaled levodopa-carbidopa treatment as well as a thin-film strip by Cynapsus.
One of the most frustrating symptoms of advanced Parkinson’s disease is longer periods of time during which movement is poor (the “off state”). A dopamine antagonist is a powerful and fast-acting injectable medication that promptly relieves symptoms of PD within minutes, but only provides 30 to 60 minutes of benefit. Examples of these types of medications are Ropinirole (brand name Requip®), Pramipexole (brand name Mirapex®), and Rotigotine (Neupro® patch). These medications can be quite effective when taken in conjunction with Sinemet by allowing patients to take a lower dose of Sinemet, thus potentially reducing side effects.
Anticholinergics, MAO-B Inhibitors & COMT Inhibitors
Anticholinergics can be helpful for tremor and may ease dystonia associated with wearing-off or peak-dose effect. Anticholinergics decrease the activity of acetylcholine, a neurotransmitter that regulates movement. MAO-B inhibitors block an enzyme in the brain that breaks down levodopa. Both have been shown to delay the need for Sinemet when prescribed in the earliest stage of Parkinson’s, and have been approved for use in later stages of PD to boost the effects of Sinemet.
COMT inhibitors are used primarily to help with the problem of wearing-off by blocking the metabolism of levodopa, prolonging its effect.
Exelon Patch (rivastigmine transdermal system) is a prescription medication used to treat mild, moderate and severe memory problems associated with Alzheimer’s or Parkinson’s disease. The active ingredient, rivastigmine, is available in both pill and patch form. It can improve mental function and slow the progression of dementia. Rivastigmine also was shown to improve gait variability of patients with PD without dementia during normal walking and performance of a simple cognitive task in an eight-month phase 2 study conducted in the U.K.
The most common side effects of Exelon Patch include depression, headache, anxiety, dizziness, stomach pain, urinary tract infections, muscle weakness, tiredness, and trouble sleeping.
The prevalence of depression in patients with Parkinson disease (PD) is approximately 40 percent. Many patients with PD can benefit from a prescribed anti-depressant; however, psychiatric medications such as Citalopram or Resperidone may worsen the motor symptoms of individuals with PD.
Anti-depressants such as Celexa, Ellebi (a tricyclic antidepressant), Zoloft and Lexapro are often prescribed with fewer ancillary symptoms, although Lexapro should not be taken if you also are taking an MAO inhibitor, as this could cause a dangerous interaction.
Nuplazid−a drug for people with Parkinson’s experiencing hallucinations and delusions−is now available with a doctor’s prescription. The National Parkinson Foundation has a free Helpline at 1-800-473-4636 for questions about this new drug, which works primarily on the serotonin receptor.
Consider a Medication Review
If you are interested in undergoing a medication review or would like to learn more about new medications for Parkinson’s, please contact Neurology Solutions or call 512-865-6310 for information and to make an appointment. Read on for information on How to Prepare for Your Neurologist Appointment.
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