Parkinson’s Medications

By Dr. Dean P. Sutherland

Over the last 40 years, since the introduction of Sinemet, there have been some very important developments on the medication front. Several new medicines have been released over the last 10 years and many more are in the research and development phase right now. 

Below is a partial list of the medications that we commonly use for treatment of Parkinson Disease and other related conditions. In general, PD meds are associated with certain benefits (improvement in muscle tone, reduction of tremor, increase in motor speed, improvement of gait and posture, greater sense of well-being, etc). They are also associated with side-effects such as constipation, hallucinations, dyskinesias, low blood pressure, confusion, obsessive/compulsive thoughts and behaviors, nausea, and more.

The important point to keep in mind is that each patient is a different individual and will respond in a manner different than the next patient, so treatment must be tailored to you as an individual. Using an algorithmic or cookbook approach to treatment can often be counterproductive. You should be monitored for effectiveness of the medications as well as for side-effects.

Carbidopa/Levodopa (Sinemet)

Considered the “Gold Standard” for PD meds ever since its release 40 years ago. Sinemet acts within 20 to 40 minutes of ingestion and relieves most, if not all, of the symptoms of the disease. It acts directly on the dopamine receptors in the brain.


A combination of Carbidopa/Levodopa and Entacapone, taken as a single pill, for easier dosing and smoother coordination of these medications.

Ropinerole (Requip)

A powerful “agonist” which means that it acts directly on the dopamine receptors in the brain and mimics Sinemet in many respects.

Apomorphine (Apokyn)

An injection just under the skin 2 or 3 times a day, it acts quickly and directly on the dopamine receptors in the brain.

Amantidine (Symmetrel)

Reduces dyskinesia secondary to Sinemet and may reduce tremor. Unclear how it works, but it seems to help release dopamine from nerve cells.

Benztropine (Cogentin)

Another cholinergic drug,
similar to trihexyphynidyl

Entacapone (Comtan)

A “helper molecule” that inhibits the breakdown of Levodopa, allowing more it to get into the brain. It can provide 1-2 more hours of benefit per day from Sinemet (it does not work without Sinemet). As a result, it can worsen any side effects of Sinemet. Commonly, it causes diarrhea or loose stool and turning urine a bright yellow color.

Pramipexole (Mirapex)

A powerful “agonist” which means that it acts directly on the dopamine receptors in the brain and mimics Sinemet in many respects.

Rotigotine (Neupro)

Contained in a patch applied daily to the skin for continuous release of medication. It acts directly on the dopamine receptors in the brain. Despite great success in some patients, it was recently taken off the market in the U.S. due to manufacturing problems.

Selegiline (Eldepryl)

Inhibits an enzyme that breaks down dopamine, allowing it to stay in the brain longer. Despite many laboratory studies suggesting a protective effect on the brain, this has not panned out. Warnings relate to high blood pressure with certain foods and medicines.

Trihexyphenidyl (Artane)

An older medication which acts mainly on the cholinergic system, rather than the dopamine system. May be effective for tremor early on and may be used to treat dystonia as well. May cause confusion.

Associated medications:

Modafinil (Provigil)

A novel drug used to treat sleepiness and fatigue, can be very effective in Parkinson and Sleep Disorder patients.

Quetiapine (Seroquel)

A newer anti-psychotic drug that can be used to treat hallucinations with some success.

Valproic acid (Depakote)

An anti-seizure drug that may be used in some cases of hallucination or agitation.


A new compound that is an extended release forumation of carbidopa-levadopa so patients may take Rytary less frequently.

Istradefylline (Nourianz)

A prescription medicine used with levodopa and carbidopa to treat adults with Parkinson’s who are having “off” episodes.

Methylphenidate (Ritalin)

An older stimulant that can be used to treat depression, sleepiness, and fatigue (as well as ADHD in children).

Clozapine (Clozaril)

An older anti-psychotic that can be used to treat hallucinations in PD patients; effective, but must be closely monitored.

Botulinum toxin (Botox; Myobloc)

A neuromuscular agent, delivered by injection, that weakens muscles. Botulinum toxin has been hailed recently as the best treatment for dystonia. It can also be very effective for treatment of drooling and occasionally for headache or tremor.