Download Understanding Medications - Parkinson`s Disease Foundation

Treating Parkinson’s
Understanding Medications
Parkinson’s is a very individualized disease and each person who lives with it requires a unique treatment plan. Although researchers are attempting to develop treatments that will slow down
or reverse the disease, no such therapy has yet been approved by the United States Food and Drug Administration (FDA). The goal of treatment is to reduce symptoms with as few side effects as
possible. It is important to note that medications work best when they are taken on a regular schedule, and when combined with exercise, good nutrition and adequate sleep.
Class/Type and Medications
How It Works
What To Know
Potential Side Effects
Levodopa
Carbidopa/Levodopa (Sinemet®)
Carbidopa/Levodopa controlled
release (Sinemet CR®)
Carbidopa/Levodopa orally
disintegrating tablet (Parcopa®)
Carbidopa/Levodopa/
Entacapone (Stalevo®)
Carbidopa/Levodopa extendedrelease capsules (Rytary®)
Carbidopa/Levodopa enteral
suspension (Duopa™)
Levodopa is the gold standard medication for Parkinson’s
disease with the broadest antiparkinsonian effects of any
treatment. Levodopa works
by replacing the dopamine
lost in Parkinson’s. In the
brain, certain cells are able to
convert levodopa to dopamine. It is combined with
carbidopa to prevent nausea
and ensure the conversion
from levodopa to dopamine
occurs in the brain rather than
in the bloodstream.
Carbidopa/Levodopa is the most potent and effective medication for Parkinson’s. Most
formulations are taken as a pill. A pill that dissolves in the mouth (carbidopa/levodopa
orally disintegrating tablet) may be helpful if swallowing becomes difficult. More recently-approved preparations offer a longer period of effectiveness (carbidopa/levodopa controlled release, carbidopa/levodopa extended-release, carbidopa/levodopa/entacapone).
Duopa is a gel formulation of the drug that is pumped directly into the small intestine
through a tube that is placed during a surgical procedure. The right choice among these
forms depends on the severity of a person’s disease, the nature of side effects and a person’s response to the medications, and is the result of a partnership between patient and
doctor. People with Parkinson’s should be aware of which preparation they are taking, as
there are many different pill sizes, colors, dose strengths and manufacturers. The decision about when to begin using carbidopa/levodopa is different for every person. Some
people have been reluctant to begin medication due to fears of toxicity or earlier onset
of side effects; however, studies have shown no evidence of toxicity. Most neurologists
agree that waiting too long before starting these medications may lower quality of life
and put a person at risk for falling.
Early in the course of Parkinson’s, side effects include low blood pressure,
nausea, dry mouth and dizziness. As the disease advances, motor side
effects may include “wearing-off” of drug benefit between doses and the
development of extra movements (dyskinesia or dystonia). In advanced PD,
confusion and hallucinations are side effects. The entacapone that is included
in carbidopa/levodopa/entacapone may also cause discoloration of urine,
saliva and perspiration, as well as diarrhea. The FDA is investigating whether
carbidopa/levodopa/entacapone increases the risk of prostate cancer, but
this link has not been proven. Health care professionals should follow current guidelines for prostate cancer screening. Duopa treatment may cause
skin irritation at the site of the tube and complications related to the pump
are common.
Dopamine Agonists
Apomorphine (Apokyn®)
Bromocriptine (Parlodel®)
Pramipexole (Mirapex®)
Pramipexole dihydrochloride
extended-release (Mirapex ER®)
Ropinirole (Requip®)
Ropinirole extended-release
tablets (Requip® XL™)
Rotigotine transdermal system
(Neupro®)
Dopamine agonists are drugs
that stimulate the parts of
the human brain that are
influenced by dopamine. In
effect, the brain is tricked into
thinking it is receiving the
dopamine it needs.
In general, this class of medications is not as effective in relieving symptoms of Parkinson’s as carbidopa/levodopa. The exception is apomorphine, an injectable dopamine
agonist that works rapidly, lasts only 30 minutes or so and may provoke dyskinesias.
Doctors may prescribe agonists as an initial Parkinson’s therapy or as a complement to
levodopa in those who develop symptom fluctuations. Dopamine agonists should be
started in low doses, with a gradual increase in dosage to prevent side effects. Apomorphine requires training in its administration, and is used as a “rescue” therapy for people
who experience sudden spells of wearing-off immobility. The rotigotine patch can be
helpful for individuals seeking a long-acting medication and for those who are undergoing
surgery and cannot swallow.
Mild, common side effects include nausea and lightheadedness due to low
blood pressure. More serious side effects can include leg swelling, hallucinations, sleepiness (including sudden sleepiness) and in some people,
impulse control disorders (excessive shopping, gambling, sex drive or
eating). Dopamine agonists may also cause extra movements (dyskinesias),
but usually in people who are also taking carbidopa/levodopa. Apomorphine
may cause severe nausea, and so people using it must also take an anti-nausea medication. The treatment of impulse control disorders usually requires
individuals to stop the drug completely. In these cases, some people develop a withdrawal syndrome, so a gradual decrease in dosage under a doctor’s
guidance (rather than stopping the medication immediately) may be advised.
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Class/Type and Medications
How It Works
What To Know
Potential Side Effects
COMT Inhibitors
(Catechol-O-Methyl Transferase)
A newer class of Parkinson’s medications, these agents have no
direct effect on PD symptoms, but instead are used to prolong
the effect of levodopa by blocking its breakdown in the body.
COMT inhibitors are used to help with wearing-off, a tendency
for PD symptoms to recur prior to the next scheduled dose of
medication. Entacapone is also a main ingredient in carbidopa/
levodopa/entacapone, listed on page 1.
Side effects include abdominal pain, back pain, constipation, nausea, diarrhea and darkening of the urine and other body fluids.
COMT inhibitors may intensify levodopa side effects including
hallucinations and dyskinesia. People who take tolcapone must
have regular liver function blood tests.
MAO-B Inhibitors
Rasagiline (Azilect®)
Selegiline or deprenyl (Eldepryl®)
Selegiline Hcl orally disintegrating
tablet (Zelapar®)
MAO-B inhibitors block an enzyme in the brain that breaks down
levodopa.
These drugs have a modest effect in suppressing the symptoms
of Parkinson’s. They are used as alternatives to levodopa in the
earliest stage of PD and are approved for use in moderate and
advanced PD to boost the effects of levodopa or dopamine
agonists. Both rasagiline and selegiline have been studied for
possible neuroprotection — i.e., whether the drugs can slow
down PD progression, but neither has been proven to do so.
Depending upon the medication, possible side effects include
agitation, dizziness, nausea, headache, nasal congestion, back
pain, mouth sores, upset stomach, low blood pressure and
indigestion. MAO-B inhibitors may aggravate dopaminergic side
effects including dyskinesia and hallucinations. Insomnia is more
common with selegiline; therefore it should be taken no later
than 1:00 PM.
Anticholinergics
These drugs work by blocking the brain chemical messenger
acetylcholine that is important in some aspects of movement
and memory. Anticholinergics are the oldest medications for
Parkinson’s but they are no longer widely used because of both
unacceptable side effects (e.g., confusion) and the availability of
more effective drugs.
Anticholinergic drugs are sometimes used for people with
early onset Parkinson’s who experience mainly tremor and may
be helpful for a certain type of extra movement in PD called
dystonia.
Potential adverse effects include blurred vision, dry mouth, constipation and urinary retention. Many people with Parkinson’s
taking anticholinergics complain of memory problems. Since
older individuals are susceptible, these agents should be avoided
in individuals over the age of 70.
Its mechanism is not entirely known. It may aid release of dopamine in the brain or delay its breakdown. It may also have some
anticholinergic properties (see above). Recently it has been found
to block the effect of the chemical messenger glutamate.
In the early stages of PD, amantadine is a mild agent that can
be used to help symptoms. In later stages of PD, it has been
found helpful in reducing extra movements (dyskinesias) that
may occur with levodopa or dopamine agonists.
Potential side effects include dry mouth, constipation, difficulty
passing urine, ankle swelling and a mottled skin rash. It may
aggravate hallucinations and may rarely cause swelling of the
cornea, causing blurred vision.
Droxidopa targets neurogenic orthostatic hypotension (nOH),
the tendency for blood pressure to drop when a person with PD
stands up. It works by increasing levels of norepinephrine.
While nOH is a common effect of moderate PD, in some people,
it can also be seen early on in the disease.
Droxidopa may cause headache, dizziness, nausea or confusion.
It also can cause high blood pressure when lying down, which
could lead to heart attack or stroke.
Entacapone (Comtan®)
Tolcapone (Tasmar®)
Benztropine mesylate (Cogentin®)
Procyclidine (not currently available in the US)
Trihexyphenidyl (Artane®)
Amantadine
Norepinephrine Precursors
Droxidopa (Northera )
™
Cholinesterase Inhibitors
Rivastigmine tartrate (Exelon )
®
Atypical Antipsychotics
Pimavanserin (Nuplazid )
™
Rivastigmine tartrate inhibits enzymes that break down acetylcholine, a chemical messenger with important memory functions. It
can improve memory function in PD and is the only medication
approved by the FDA for the treatment of dementia in PD.
Rivastigmine tartrate side effects include diarrhea, dizziness,
weakness, drowsiness, trouble sleeping, headache, increased
sweating, loss of appetite, nausea, upset stomach and weight
loss.
Pimavanserin blocks some of the effects of the chemical messenger serotonin. It is used to treat hallucinations and psychosis that
may be caused by the treatment of PD.
Pimavanserin side effects include leg swelling, nausea, confusion, constipation and difficulty walking. Treatment with
antipsychotics in elderly individuals with dementia may increase
the likelihood of death for those individuals.
A full description of each medication is beyond the scope of this fact sheet, but can be found on PDF’s website at www.pdf.org/meds_treatments. (As of August 25, 2016)
If you have or believe you have Parkinson’s disease, then promptly consult a physician and follow your physician’s advice.
This publication is not a substitute for a physician’s diagnosis of Parkinson’s disease or for a physician’s prescription of drugs, treatment or operations for Parkinson’s disease.
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© 2016 Parkinson’s Disease Foundation