Medications for Parkinson’s Disease

The use of medications for Parkinson’s disease can boost the amount of a chemical called dopamine in the brain.

While there are no standard treatments for Parkinson’s disease (PD), there are a number of medications that have been developed to help treat the symptoms of this disease, many of which are caused by a lack of dopamine in the brain. As a result, many of the common medications for Parkinson’s disease are designed to mimic or temporarily replenish those levels.

Types of Parkinson’s Disease Medications

• Levodopa (or L-dopa) (gets converted in the brain into dopamine). This is the mainstay of treatment and is most effective but also most likely to cause motor complications. It is always given with carbidopa to make sure more gets into the brain. Carbidopa-levodopa can cause nausea, lightheadedness upon standing, hallucinations, psychosis, intense urges, and dyskinesia. These side effects can often be alleviated with dose adjustments. “Off” time refers to hours during the day when the effect of the levodopa has worn off and symptoms that were otherwise controlled by the medication have recurred. These symptoms include stiffness, slowness, tremor, as well as potentially fatigue, confusion, and anxiety. “Off” time can occur when the levodopa wears off too early, takes too long to kick in, or just doesn’t kick in at all for a given dose, and can be both predictable and unpredictable.
  • Sinemet is the brand name for carbidopa-levodopa and is available in both immediate-release (IR) and controlled-release (CR or ER) formulations. However, the controlled-release formulation is not as predictable in absorption, compared to the IR formulation and has not been proven to reduce “off” time. Sinemet is taken 3 times per day to begin with but as the disease progresses the frequency may need to be increased to 5 or 6 times per day.
  • Rytary^TM is the brand name for a newer formulation of carbidopa-levodopa and is a new type of drug delivery with microcapsules within a capsule, resulting in a truly controlled release and a duration of action about an hour longer than immediate-release carbidopa-levodopa. Rytary capsules can be gently opened and sprinkled on applesauce, making it a good alternate for patients who cannot swallow capsules.
  • Parcopa is the brand name for a disintegrating form of immediate release carbidopa levodopa that can be absorbed on the tongue, also an option for patients who cannot swallow tablets.
  • Inbrija is a newer inhaled formulation of levodopa and is used as a rescue drug for “off” time as it kicks in very quickly since it is absorbed through the lungs. However, it does not last very long and is not a replacement for oral medication, because it does not have carbidopa. It can be used up to 5 times per day. In addition to the usual levodopa side effects, Inbrija can cause cough and discolored sputum.
• Dopamine agonists work on the same brain cell receptors as dopamine. Imagine the dopamine receptor as the lock and dopamine as the key. Dopamine agonists are like a different key for the same lock. Dopamine agonists have a lower risk of motor complications than levodopa but a higher risk of sleepiness, impulse control disorders (compulsive behaviors) and swelling in the legs, and are less effective than levodopa.
  • Mirapex is the brand name for pramipexole
  • Requip is the brand name for ropinirole
  • Neupro patch is the only transdermal Parkinson’s medication. This can be useful for patients who are unable to swallow.
  • Kynmobi is a rescue medication for “off’ time, which kicks in very quickly but doesn’t last very long. It is a film that gets placed under the tongue. Because nausea is very common, an anti-nausea medication needs to be given for 3 days prior to the initiation of the Kynmobi.
• MAO-B inhibitors reduce metabolism of dopamine, thereby boosting the amount of dopamine in the brain. Azilect (rasagiline) and Xadago (safinamide0) are a once-a-day medications; Eldepryl (selegiline) is taken twice a day. Effectiveness for motor symptoms is milder. Side effects include high blood pressure, insomnia and abdominal pain. They can be used by themselves or with levodopa. MAO-B inhibitors can interact with dextromethorphan, selective serotonin reuptake inhibitors, and over-the-counter serotonin boosting medications.
• COMT inhibitors reduce metabolism of levodopa, thereby boosting the amount of dopamine in the brain. They only work when taken with levodopa. Brand names include Comtan (entacapone) and Stalevo (a combination of carbidopa, levodopa and entacapone). They improve the duration of action of levodopa but can make dyskinesias (involuntary movement) worse and may cause confusion or diarrhea.
  • Comtan (entacapone) taken with each dose
  • Stalevo (a combination of carbidopa, levodopa and entacapone).
  • Ongentys (opicapone) taken once a day
• Amantadine is an antiviral medication (also used for the flu) which modulates the release of dopamine and can help for tremor or dyskinesias, but can cause swelling in the legs, insomnia, hallucinations, depression or anxiety symptoms, and blurry vision.
  • Immediate release amantadine, taken twice or thrice a day
  • Extended release amantadine (Osmolex and Gocovri)
• Adenosine 2A antagonists (Nourianz, istradefylline) are taking once a day with carbidopa/levodopa to reduce off time.
• Artane (trihexyphenidyl) blocks the acetylcholine system which is in imbalance with the dopamine system, and improving the flow of dopamine. This medication is primarily useful for patients with tremor and for the small subset of PD patients who have dystonia, but can cause confusion, anxiety, depression, dry mouth, constipation, and dry eyes.
• Treatment for non-motor symptoms associated with Parkinson’s Disease is also available.