CMHA - Treatment of Parkinson's Disease

Parkinson's Disease
Fact Sheet
About Parkinson's Disease
Medication Treatment Options
Resource Links

Treatment of Parkinson's Disease

How is Parkinson's disease treated?

There is currently no cure for Parkinson's disease (PD) but medications can often provide dramatic relief from the symptoms. Surgery also can be effective in a small number of people to treat PD. In addition, physical, occupational and speech therapy as well as a healthy diet and exercise are also beneficial for persons with PD.

Medications are used to correct the shortage of the brain chemical dopamine, which causes the symptoms of PD.

While there are many medications available to treat the symptoms of PD, there are none that actually reverse the effects of the disease. The goal of treatment is to maintain function and quality of life by relieving the most bothersome symptoms of the disease.

Several drugs may be used to treat Parkinson's disease at different stages of the disease. While keeping track of when and how to take your medications can be a challenge, it is important to understanding your medications and stick to a schedule that provides the greatest benefit.

When recommending a course of treatment, the doctor will tailor therapy to your particular condition. Since no two people react the same way to a given drug, it may take time and patience to get the dose just right. Even then, symptoms may not go away completely.

Categories of Medications

Medications for PD fall into three categories. The first category includes drugs that work directly or indirectly to increase the level of dopamine in the brain. The most common drugs for PD are dopamine precursors – such as levodopa – that cross into the brain and are then changed into dopamine. Other drugs mimic the role of dopamine in the brain or prevent or slow its breakdown.

The second category of PD drugs affects other neurotransmitters in the body in order to ease some of the symptoms of the disease. For example, anticholinergic drugs interfere with production or uptake of the neurotransmitter acetylcholine. These drugs help to reduce tremors and muscle stiffness, which can result from having more acetylcholine than dopamine.

The third category of drugs prescribed for PD includes medications that help control the non-motor symptoms of the disease, that is, the symptoms that don't affect movement.

Side Effects of PD Medications

All drugs used to treat PD can cause unpleasant side effects. The goal is to find a drug regimen that controls your symptoms without causing side effects that you cannot tolerate. Some of the medications used to treat PD cause nausea. Long-term use of PD medicines can cause movement problems (motor fluctuations), which include sudden changes in your response to the drug (called the on-off response) and involuntary twitching and writhing movements (dyskinesias).

A possible serious side effect of taking medicines for PD is excessive daytime sleepiness, including "sleep attacks" – a sudden and overwhelming sleepiness, without awareness of falling asleep. These attacks, especially if they occur while driving, can pose a great risk to people with PD.

Drugs for Parkinson's disease can also cause compulsive behaviors, such as uncontrollable gambling and shopping and an inappropriate increase in sexual activity. These behavior changes can be very upsetting and difficult for family and friends to understand. If you experience intense urges or a family member sees behavior that's out of character for you, talk to your doctor about it right away.

What drugs are currently available to treat Parkinson's disease?

Carbidopa/levodopa (Sinemet®)

Levodopa (also called L-dopa) is the cornerstone of therapy for PD. When taken by mouth in pill form, levodopa passes into the brain and is converted to dopamine. You cannot take a pill form of dopamine because dopamine cannot pass freely into and out of the brain.

When a person takes a dose of levodopa, only a very small portion of the dose actually enters the brain and is changed into dopamine inside the brain. Some of the levodopa is changed into dopamine outside the brain.

Carbidopa is combined with levodopa to prevent levodopa from being converted into dopamine in the bloodstream, which allows more of it to get to the brain. Carbidopa reduces the amount of levodopa needed to treat symptoms, preventing or reducing the nausea and vomiting often associated with levodopa treatment.

Levodopa usually helps most with bradykinesia and rigidity. Problems with balance and other non-motor symptoms may not be helped at all.

People with PD often see dramatic improvement in their symptoms after starting levodopa therapy. However, they may need to increase the dose gradually over time to maintain maximum benefit.

Side Effects. The most common side effects from levodopa include nausea, vomiting, low blood pressure and restlessness. The drug also can cause drowsiness or sudden sleep onset, which can make driving and other activities dangerous. Long-term use of levodopa sometimes causes hallucinations and psychosis.

Other troubling and distressing problems may occur with long-term levodopa use.

Dyskinesias. Dyskinesias, or involuntary movements such as twitching, twisting, and writhing commonly develop in people who take large doses of levodopa over an extended period of time. These movements may mild or severe. The dose of levodopa is often reduced in order to lessen these drug-induced movements. Doctors and patients must work together closely to find a tolerable balance between the drug's benefits and side effects.

Wearing-off Effect. The period of effectiveness after each dose of levodopa may begin to shorten, called the "wearing-off" effect. People who take levodopa may begin to notice more pronounced symptoms before their first dose of medication in the morning, and they may develop muscle spasms or other problems when each dose begins to wear off.

On-Off Effect. Another potential problem is referred to as the "on-off" effect, sudden fluctuations in movement, from normal to parkinsonian slowness and stiffness and back again. "On" and "off" periods can occur without warning as a result of fluctuating dopamine levels in the brain. "Off" time (the period of time when PD symptoms are present) usually occurs suddenly (over seconds or minutes) and may cause the person to "freeze."

You should never stop taking levodopa without your physician's knowledge. Rapidly withdrawing the drug can have potentially serious side effects, such as being unable to move or having difficulty breathing.

Dopamine Agonists

Unlike levodopa, dopamine agonists aren't changed into dopamine. Instead, they mimic the effects of dopamine in the brain and cause neurons to react as though dopamine is present. Dopamine agonists are not nearly as effective as levodopa in controlling the symptoms of Parkinson's disease. They can be given alone in the early stages of the disease. In later stages of the disease, they can be given with levodopa in order to lengthen the duration of response to levodopa in patients who experience wearing off or on-off effects.

Pill forms of dopamine agonists include pramipexole (Mirapex®), ropinirole (Requip®/Requip XL®) and bromcriptine (Parlodel®).

Apomorphine (Apokyn™) is a fast-acting injectable dopamine agonist used for treating occasional episodes of immobility associated with PD, when muscles become "stuck" or "frozen" and you are unable to rise from a chair or perform daily activities. Apomorphine can be taken with an antinausea drug to prevent side effects of severe nausea and vomiting.

Side Effects. Older adults may be more sensitive to the side effects of dopamine agonists, including dizziness, confusion, daytime drowsiness or sudden sleep onset (sleep attacks), and hallucinations (seeing, hearing, or feeling things that are not there). Additional side effects include nightmares, edema (swelling due to excess fluid in body tissues), low blood pressure when standing, and dyskinesias–sudden uncontrolled movements of the body, such as the face, tongue, arms, hands, head, and upper body.

Dopamine agonists may also increase your risk of compulsive behaviors, such as uncontrollable desire to gamble, increased sex drive and hypersexuality, and compulsive shopping or overeating. If you are taking these medications and experience intense urges or start behaving in a way that's out of character for you, talk to your doctor.

Bromocriptine may also cause nausea, vomiting and headache. Fibrosis, or a buildup of fibrous tissue in the heart valves or the chest cavity, has been reported with bromocriptine use. Fibrosis usually goes away once the drug is stopped.

Monoamine Oxidase-B (MAO-B) inhibitors

Selegiline (Eldepryl®) and rasagiline (Azilect®). These drugs block the enzyme monoamine oxidase B (MAO-B) in the brain, which helps prevent the breakdown of both naturally occurring dopamine and dopamine formed from levodopa. MAO-B inhibitors cause dopamine to build up in surviving nerve cells, reducing symptoms of PD.

MAO-B inhibitors can delay the need for levodopa when prescribed in the earliest stages of PD. When given with levodopa, MAO-B inhibitors appear to enhance and prolong the response to levodopa and may reduce the wearing-off effect.

Side Effects. Side effects include confusion, headache, hallucinations and dizziness, nausea, orthostatic hypotension, and insomnia.

Serious Drug Interactions. MAO-B inhibitors should not be taken with antidepressants, the antibiotic ciprofloxacin (Cipro), the herb St. John's wort or certain narcotic pain medications, such as mepiridine (Demerol). Combining these drugs can be harmful. You should always heck with your doctor before taking any additional medications with an MAO-B inhibitor.

COMT Inhibitors

Entacapone (Comtan®) and Tolcapone (Tasmar®). COMT, which stands for catechol-O-methyltransferase, is enzyme that breaks down levodopa. COMT inhibitors must be taken with levodopa. COMT inhibitors prolong the effects of levodopa by preventing its breakdown. This allows a larger amount of levodopa to reach the brain, which raises dopamine levels there.

Entacapone is also available as a combined product with levodopa and carbidopa, called Stalevo®.

Side Effects. The most common side effect is diarrhea. Other side effects include headache, abdominal pain and urine discoloration (bright yellow or orange urine). By increasing the amount of levodopa that reaches the brain, COMT inhibitors can worsen levodopa side effects, including involuntary movements (dyskinesias), low blood pressure when standing up (orthostatic hypotension), fainting, nausea, sleep disturbances, and hallucinations (seeing or hearing things that aren't really there).

In a few rare cases tolcapone has caused severe liver disease, so its use has been limited to only those situations in which all other treatment options have failed. People taking tolcapone need regular monitoring of their liver function. Liver failure has not been associated with entacapone.

Anticholinergics

Anticholinergic medications are rarely used in older adults or people who have developed mental impairment or memory problems. Older adults are more likely to have severe side effects from anticholinergics, such as confusion and hallucinations (seeing or hearing things that aren't really there), and anticholinergics can contribute to memory problems.

Anticholinergics decrease the activity of the neurotransmitter acetylcholine and have been used for many years to help reduce the tremors and muscle rigidity associated with PD. However, their modest benefits are often outweighed by their side effects.

Some examples of anticholinergic drugs include biperiden (Akineton®), benztropine (Cogentin®), trihexyphenidyl (Artane®), procyclidine (Kemadrin®) and orphenadrine.

Side Effects. Side effects from anticholinergics are very common and may include memory problems, confusion, sleepiness, constipation, dry mouth and eyes, blurred vision, hallucinations, and impaired urination.

Amantadine (Symmetrel)

Amantadine should be used with caution in older adults because of the risk of impaired thinking and reasoning. Amantadine is an old antiviral drug that can help reduce symptoms of PD and dyskinesias caused by levodopa. It may be used alone in the early stages of the disease, and again in later stages to treat the involuntary movements (dyskinesia) caused by levodopa.

Side Effects. Amantadine's side effects may include dizziness, weakness, dry mouth, blurred vision, confusion, constipation, insomnia (difficulty falling or staying asleep), nightmares, agitation, swelling of the ankles, a purple mottling of the skin and, hallucinations (seeing or hearing things that aren't really there).

What non-medication treatments are available for Parkinson's disease?

A wide variety of complementary and supportive therapies may be used for Parkinson's disease. Physical therapy, speech and language therapy, and occupational therapy help with gait and voice disorders, tremors and rigidity, and decline in mental functions. Other supportive therapies include diet and exercise. These therapies should be incorporated into the treatment plan at the onset of the disease. Unfortunately, this does not always happen.

Talk to your doctor about how you can benefit from non-medication therapies.

Physical Therapy (PT). Exercise is important for maintaining function in Parkinson's disease. Physical therapy can help you compensate for the changes brought about by PD. Physical therapy can help improve mobility, range of motion and muscle tone. A physical therapist can teach you exercises to strengthen and loosen muscles. Many of these exercises can be performed at home. A physical therapist can also work with you to improve your gait and balance.

The goal of physical therapy is to improve independence and quality of life by improving movement and function and relieving pain. Physical therapy can help with:

Balance problems
Lack of coordination
Fatigue
Pain
Gait
Immobility
Weakness

Speech Therapy. More than 75 percent of individuals with Parkinson's disease have voice and speech disorders, yet, only three to four percent receive any type of speech therapy. These voice and speech problems start early in the disease and progressively diminish quality of life. Medicine and surgery may dramatically improve the other symptoms of PD, but they do little to improve speech problems. Speech therapy is the only way to improve problems with speaking and swallowing in persons with PD.

Most people with Parkinson's have soft voices because the disease can impair muscles of the voice box, throat, mouth, tongue, and lips. Subtle changes may happen early in the disease, with the person's voice becoming softer and flat in tone, making it hard to hear. Voice and speech symptoms in PD include:

Talking in a monotone, with little inflection in pitch
Reduced speech volume (hypophonia)
Breathy or hoarse voice
Mumbled speech, imprecise articulation
Difficulties initiating speech
Difficulty with articulation of sounds or syllables (dysarthria)
Hesitant, sometimes stuttering speech
Short, fast rushes of speech
Difficulty swallowing (dysphagia)

Speech therapists can help people with PD maintain as many communication skills as possible. They also teach techniques that conserve energy, including non-verbal communication skills. Speech therapists can also evaluate swallowing function and recommend changes as necessary.

The Lee Silverman Voice Therapy Program – an intensive program of voice exercises that targets vocal intensity, quality and variation – has demonstrated significant value for people with PD. You should be referred to a speech therapist experienced in administering the Lee Silverman Voice Therapy Program.

Occupational therapy (OT). OT can benefit people with PD at all stages the disease. An occupational therapist can help people with PD stay active in daily life by improving skills, showing different ways to complete tasks, introducing handy equipment and recommending changes to the home or workplace to promote independence. OT provides assessment, treatment, and recommendations in the following areas:

Arm and hand therapy
Handwriting aids
Home modification information
Driver evaluation and vehicle modification information
Cooking and homemaking adaptations
Eating and dinnerware adaptations
Ways to make the most of your energy
Computer modifications
Workplace or work equipment modifications
Leisure skill development
Manual or electric wheelchair use
Bathtub and toilet equipment use
Dressing and grooming aids

Exercise. Although exercise can't stop the progress of PD, maintaining muscle strength and agility can help reduce the disability associated with the disease. Exercise can help people with PD improve their mobility and flexibility and balance, as well as their emotional well-being. Research shows that people with Parkinson's disease who exercise regularly do better than those who don't. Group activities, such as the the Parkinson's Learning Lifelong Useful Skills program provides involvement with others and can reduce the isolation and depression some people with PD feel.

Other Complementary Therapies. Massage therapy, yoga, tai chi, hypnosis, acupuncture, and the Alexander technique, which improves posture and muscle activity may provide benefit for people with PD.

What surgical options are available for Parkinson's disease?

There are some surgical options for patients with Parkinson's disease, the most common of which is known as Deep Brain Stimulation (DBS). This form of surgery is often reserved for people with advanced PD and poorly controlled symptoms or drug-induced tremor. It involves implanting a wire electrode deep within the part of the brain that controls movement. The amount of stimulation delivered by the electrode is controlled by a pacemaker-like device called a pulse generator, which is placed under the skin in the upper chest.

The pulse generator and electrodes painlessly stimulate the brain in a way that helps to stop many of the symptoms of PD, such as tremor, bradykinesia and rigidity. DBS usually reduces the need for levodopa and related drugs, which in turn decreases involuntary movements (dyskinesia) and other side effects. It also helps to relieve "on-off" fluctuation of symptoms.

DBS is not beneficial for people who don't respond to carbidopa-levodopa. Older adults with PD, who have only a partial response to levodopa, may not improve with DBS.
DBS is not a cure for Parkinson's, and it does not slow disease progression. DBS usually does not help with speech problems, "freezing," posture, balance, anxiety, depression, or dementia.
Serious risks of this procedure are uncommon, but include brain hemorrhage or stroke. Infection is also a risk, and sometimes requires parts of the device to be replaced.