APPENDIX C

List of Commonly Prescribed Medications

PARKINSON’S DISEASE

Levodopa Preparations

Carbidopa/levodopa (Sinemet, Sinemet CR, Parcopa)
Carbidopa/levodopa/enatacapone (Stalevo)

Levodopa is the mainstay of Parkinson’s disease treatment. It gets changed by the brain’s own cells into dopamine, which is deficient in people living with Parkinson’s. Levodopa is often combined with carbidopa in the USA or benserazide in other parts of the world. Carbidopa and benserazide prevent breakdown of levodopa in the gut and allow more levodopa to get in the brain. Most people will eventually end up on some form of levodopa. It comes in a regular release form, a long-acting formulation, as well as a formulation that melts in the mouth (Parcopa). There is also a formulation called Stalevo, where levodopa is combined with a COMT inhibitor (see COMT inhibitors below). Common side effects include nausea/vomiting, low blood pressure, lightheadedness with standing, confusion, and dyskinesias.

Dopamine Agonists

Ropinirole (Requip)
Pramipexole (Mirapex)
Rotigotine (Neupro)
Apomorphine (Apokyn)
Cabergoline and Lisuride (available in other countries but not approved for use in the US)

The dopamine agonists are chemically similar to dopamine itself and act on the dopamine receptors of the brain. They help all the motor symptoms of Parkinson’s disease, although not quite as effectively as levodopa. Ropinirole and pramipexole are oral forms of the medication. Rotigotine is administered by a patch form. Apomorphine is given through an injection and is very short acting. Common side effects include nausea, lightheadedness with standing, leg swelling sleepiness, hallucinations, and impulse control disorders such as pathologic gambling, hypersexuality, and compulsive shopping.

COMT Inhibitors

Entacapone (Comtan)
Tolcapone (Tasmar)

COMT is an enzyme that breaks down dopamine in the brain. These medications block this enzyme so that dopamine stays around for a longer period of time. These medications are approved for use with levodopa when people develop wearing off. Entacapone is most commonly used and comes in a preparation where it is combined with carbidopa and levodopa (Stalevo). Tolcapone is rarely used because it can cause significant liver problems. The main side effects include discolored urine, dyskinesias, nausea, and diarrhea.

MAO-B Inhibitors

Selegiline (Eldepryl, Deprenyl)
Zydis selegiline (Zelapar)
Rasagiline (Azilect)

Monoamine oxidase (MAO) is another enzyme that breaks down dopamine in the brain, and these medications block it. These medications are approved for early treatment of Parkinson’s disease as well as for wearing off and motor fluctuations. They have been suggested to possibly slow down clinical progression, but this has never been proven. Selegiline is broken down into an amphetamine by the body and can cause insomnia. The Zydis selegiline formulation dissolves in the mouth. Common side effects include agitation, insomnia, vivid dreams, and hallucinations. It may also worsen dyskinesias. There is a concern with this class of medications in terms of interactions with tyramine, a chemical that is present in red wine and cheeses. MAO inhibitors also may have a lot of drug–drug interactions with antidepressants, anesthetics, and pain medications.

Amantadine

(Symmetrel)

Amantadine is often used in early Parkinson’s for tremor and mild symptoms. It is used in advanced Parkinson’s disease to reduce dyskinesias. The common side effects include nausea, confusion, and leg discoloration. It can also contribute to hallucinations.

Anticholinergics

Trihexyphenidyl (Artane)
Benztropine (Cogentin)
Ethopropazine (Parsitan)

These medications are helpful only for tremor in Parkinson’s disease, not slowness or stiffness. Their use is limited because of the side effects, which include confusion and other memory issues, hallucinations, drowsiness, dry mouth, dry eyes and blurry vision, and retention of urine.

ESSENTIAL TREMOR

Propranolol

(Inderal)

Propranolol is a beta-blocker, which is a class of medications commonly used to treat high blood pressure, but it is approved by the FDA for essential tremor. The main side effects are a slow heart rate and low blood pressure. Other beta-blockers may be used (atenolol, metoprolol, and nadolol), but they typically are not as good as propranolol.

Primidone

(Mysoline)

This is an antiseizure medicine that is primarily used nowadays to control the tremor seen in essential tremor. Primidone and propranolol are considered the top two medications for essential tremor. Common side effects include sleepiness, balance problems, dizziness, and fatigue.

Benzodiazepines

Clonazepam (Klonopin)
Diazepam (Valium)
Lorazepam (Ativan)
Alprazolam (Xanax)

Although used primarily for anxiety, they can be helpful for tremor as well. Main side effects are sleepiness and dizziness. Some may also experience confusion and problems with thinking and memory. There is a chance of developing addiction or dependence with these medications.

Topiramate

(Topamax)

Topiramate is another antiseizure medication that can control tremor. It is typically used only when a person cannot tolerate or does not respond to propranolol or primidone. Side effects include numbness or tingling, weight loss, fogginess with thinking, or memory loss.

Gabapentin

(Neurontin)

Gabapentin is an antiseizure medication that is also prescribed often for chronic pain. Like topiramate, it can help tremor, but is considered only when individuals fail propranolol or primidone. It is generally well tolerated but can cause sleepiness, fatigue, balance problems, and nausea.

DYSTONIA

Anticholinergics

Trihexyphenidyl (Artane)
Benztropine (Cogentin)
Ethopropazine (Parsitan)

These medications block a chemical in the brain called acetylcholine. It is unclear how these medications help dystonia, but they certainly can. Side effects are common and include confusion and other memory issues, drowsiness, hallucinations, dry mouth, dry eyes and blurry vision, and retention of urine, although young people with dystonia can tolerate high doses without significant side effects.

Benzodiazepines

Clonazepam (Klonopin)
Diazepam (Valium)
Lorazepam (Ativan)
Alprazolam (Xanax)

These medications are also listed under ET but can also help relax spasms in people with dystonia. The common side effects are sleepiness, dizziness, confusion, and problems with thinking and memory. Similar to anticholinergics, some people with dystonia can tolerate high doses of benzodiazepines without significant side effects.

Baclofen

(Lioresal)

Baclofen is a medication that is similar to gamma-aminobutyric acid (GABA), a natural chemical in the body, and is commonly used to treat spasticity and dystonia. It may be taken by mouth or given intrathecally, where it is infused directly into the fluid surrounding the spinal cord. The main side effects include confusion, dizziness or lightheadedness, drowsiness, nausea, and muscle weakness.

Levodopa Preparations

Carbidopa/levodopa (Sinemet, Sinemet CR, Parcopa)
Carbidopa/levodopa/enatacapone (Stalevo)

See this section under Parkinson’s disease for how it works and common side effects. There is a small group of dystonia people that respond to levodopa. Although levodopa does not help everyone with dystonia, the ones who respond to it observe a very significant beneficial effect. As a result, most people should at least try this medication before considering DBS surgery or other surgical treatments.

Tetrabenazine

(Xenazine)

Tetrabenazine is a drug that depletes dopamine in the brain. Not everyone with dystonia will respond, but it may be helpful for a select group of individuals. It is available in the USA through a specialty pharmacy. Side effects include depression and parkinsonism.

Botulinum Toxin

onabotulinumtoxinA (Botox)
abobotulinumtoxinA (Dysport)
incobotulinumtoxinA (Xeomin)
rimabotulinumtoxinB (Myobloc)

Botulinum toxin is an injectable medication that blocks the signal from the nerve to the muscle. When the muscle does not get a signal to contract, it relaxes and helps dystonia. Botulinum toxin is considered first-line therapy for dystonias located to one body region. Side effects include bleeding, bruising, pain with injection, and weakness of the muscles injected. Some people can get a flu-like reaction. Botulinum toxin can also spread to other structures throughout the body, such as the diaphragm, and can cause breathing difficulties.