Parkinson's: Therapies - Medical Essentials
There have been many advances in treatments for Parkinson’s that can offer a much better quality of life to people with Parkinson’s than was possible a few years ago. This trend is likely to continue.
There is no cure for Parkinson’s disease, but a variety of medicines sometimes help symptoms dramatically.
The NICE Guideline for Parkinson’s disease (which covers England and Wales) states that people with suspected Parkinson’s should be referred quickly (within 6 weeks) and untreated to a specialist with expertise in the differential diagnosis of this condition. The Guideline also recommends that the diagnosis of Parkinson’s should be reviewed regularly (every 6-12 months).
Parkinson’s itself is not a fatal condition. With the treatment that is now available, life expectancy for someone with Parkinson’s is fairly normal and none of the drugs that are used for Parkinson’s have any serious side effects that could cause death. That said, occasionally in people who are seriously disabled (usually those who have had Parkinson’s for many years), their general physical and mental condition can either cause or exacerbate other illnesses and so contribute to the final cause of death.
DRUG TREATMENTS
People with Parkinson’s disease often take a variety of medications in different doses in order to manage the symptoms of the disease. These factors, combined with the frequency with which medications must be taken, can result in confusion. People with Parkinson’s and their caregivers should become familiar with their medications in order to use them most effectively and avoid possible interactions. Understanding a medication regime and sticking to it will provide the greatest benefit from the drug and avoid unpleasant “off” periods due to missed doses or confusion. We advise making a list of the medications to be taken in a day, and then making a written note on the list saying at what time you take each dose of each medicine.
Although there are general guidelines that doctors use to choose a treatment regimen, each patient must be individually evaluated to determine which drug or combination of drugs is best for them. For some, a “first choice” drug might be one of the levodopa preparations, and for others, an initial prescription may be given for one of the agonists, an MAO inhibitor or an anticholinergic. The choice of drug treatment depends on many variables including symptom presentation, other concurrent health issues (and the medications being used to treat them) and a person’s age
Drug treatments include:
Levodopa / Carbidopa
LEVODOPA is a substance that is converted into dopamine by an enzyme in the brain. It is then released by brain cells and activates dopamine receptors allowing for normal function of the movement control centres of the brain. Forty years after its discovery, levodopa remains the most effective medication for Parkinson’s disease. In fact, 70 to 80 percent of treated Parkinson’s patients are on levodopa therapy. Levodopa is the “gold standard” by which all treatments for Parkinson’s are measured.
Levodopa combined with CARBIDOPA represented a significant improvement in the treatment of Parkinson’s disease. The addition of carbidopa prevents levodopa from being converted into dopamine in the bloodstream, allowing more of it to get to the brain. Therefore, a smaller dose of levodopa is needed to treat symptoms. In addition, the nausea and vomiting often associated with levodopa treatment is greatly reduced by the presence of carbidopa.
With increased dosing and prolonged use of levodopa, patients can experience other side-effects including dyskinesias (spontaneous, involuntary movements) and "on-off" periods when the medication will suddenly and unpredictably start or stop working.
Carbidopa may be combined with levodopa and entacapone in a combination tablet for patients who experience end-of-dose "wearing-off". While carbidopa reduces the side effects of levodopa, entacapone extends the time levodopa is active in the brain (up to 10 percent longer).
Check with a doctor before taking any of the following to avoid possible interactions: antacids, anti-seizure drugs, anti-hypertensives, anti-depressants and high protein food (see our section on Diet).
Dopamine agonists are drugs that stimulate the parts of the human brain that receive dopamine. In effect, the brain "thinks" it is receiving dopamine, so these drugs help satisfy the brain’s need for dopamine. Dopamine agonists can be taken alone or in combination with medications containing levodopa. Agonists may include bromocriptine, pramipexole and ropinirole.
Consult your doctor before taking any of the following to avoid possible interactions: alcohol, anti-psychotics, medications that lower blood pressure, thiothixene, chlorprothixene, haloperidol), metoclopramide, phenothiazines, thiozanthenes, cimetidine, phenothiazines, butyrophenones, Ciprofloxacin and
benzodiazepines. Some of these drugs may be sold under other commercial names, so be sure to check what else you can and cannot take if you are prescribed a dopamine agonist.
Anticholinergics (trihexyphenidyl, benztropine mesylate, procyclidine, etc.) do not act directly on the dopaminergic system. Instead they decrease the activity of another neurotransmitter that controls movement, called acetylcholine, to balance out the production of dopamine and acetylcholine. In general, mild PD that consists of tremor at rest can often be treated initially with anticholinergic agents. Adverse effects of these drugs include blurred vision, dry mouth and urinary retention. Anticholinergics may be contraindicated in older patients because they could cause confusion and hallucination.
Anticholinergics can interact badly with antihistamines, alcohol and a number of drugs. Be sure to check what else you can and cannot take with your doctor.
MAO-B inhibitors such as selegiline or deprenyl are used to block an enzyme in the brain that breaks down levodopa. They have been shown to delay the need for levodopa/carbidopa when prescribed in the earliest stage of Parkinson’s, and can also be useful in later stages of the disease to boost the effects of levodopa/carbidopa. Possible interactions may include anti-depressants, narcotic pain killers and decongestants. Check with a doctor before taking any medications with these.
COMT inhibitors such as entacapone represent a different class of Parkinson’s medications and they must be taken with levodopa. COMT inhibitors prolong symptom relief by blocking the action of an enzyme which breaks down levodopa, allowing a larger amount of levodopa to reach the brain, which raises the dopamine level. This helps provide a more stable, constant supply of levodopa.
MANAGING MEDICATIONS
Taking medications for Parkinson’s disease is straightforward for most people during the first several years of treatment. The effect of each dose usually lasts well into the period after the next dose, and delaying a dose even by an hour does not disrupt the effective coverage of symptoms.
The situation is different for many people who have been taking Parkinson’s medications for several years (usually five years or more). In these stages of the disease, effective relief from symptoms can depend on carefully following a regular schedule of medication doses. There are several ways for Parkinson’s patients to achieve the greatest possible benefit from their medications. Since in the more advanced stages of Parkinson’s disease the
symptoms are often unpredictable and can fluctuate daily, it is important to take an active role in finding a routine for yourself that makes the most of the medicine. Notice how long it takes for a pill to work and how long its positive effects remain. Note if the pills should be taken with food, between meals or on an empty stomach and how it feels when medication starts to wear off. The answers to these questions can help explain how the pill works and possibly increase "on" time.
People with Parkinson’s must know what medications they are taking, when and why. This can be achieved by working primarily with one pharmacist. A pharmacist will note all of the medications a person is taking in a computer, which safeguards them from any interactions. Another way to control this information is by constructing your own medication chart or list. As we’ve said before, it’s best to write down what you’re taking, when you should take it, and note down when you actually take it. Having this information in writing will make all the difference for you and will help your doctor and neurologist to monitor your treatment and its results.
Organisation is a key factor in getting the most from Parkinson’s medications. Since several medications will probably be taken at different times of the day, a timing device can be crucial in avoiding missed doses. Talking systems, beeping watches and multi-alarm timers are widely available. These systems can be both discreet and loud, with vibrating and sound features. In addition, pill dispensers organise pills by day and time to eliminate carrying several large prescription bottles.
Interactions between other medications and Parkinson’s drugs can be dangerous and even life-threatening, so make sure your pharmacist (and ideally your doctor) knows of all medications and supplements you’re taking.
SURGERY FOR PARKINSON’S
Surgery for Parkinson’s disease and other movement disorders has been available since the 1960s. Back then, surgery was used to destroy a small part of the brain called the globus pallidus. This type of surgery is still done today although less frequently because of the availability of deep brain stimulation.
The surgery to destroy the globus pallidus is called a pallidotomy. It is thought that the globus pallidus becomes overactive in Parkinson’s disease. This overactivity acts like a brake and slows or diminishes movement. Pallidotomy is a way to destroy the overactive globus pallidus to improve the symptoms of Parkinson’s disease.
This surgery is effective but carries significant risks. Pallidotomy requires purposeful destruction of the brain. If the surgeon is off by even a fraction of an inch, the surgery may not be effective and severe complications can result.
Deep Brain Stimulation is a way to inactivate the globus pallidus without purposefully destroying part of the brain. Therefore, the risks are much less. In deep brain stimulation, an electrode is placed with the tip of the electrode in the globus pallidus. Introducing a small electric current through the electrode has the same effect as pallidotomy without actually destroying parts of the brain.
The electrode for deep brain stimulation is left in the brain. It is connected by a wire to a pacemaker-like device that is implanted under the skin over the chest.
Deep brain stimulation offers a number advantages. The electrical stimulation is adjustable, whereas surgical destruction is not. The electrode has four metal contacts that can be used in many different combinations. Even if one electrode contact is not in the exact location, it is likely that one of the others or some combination of electrical contacts will be closer to the proper target. As the patient’s response to surgery changes over time, the stimulation can be adjusted without the necessity of repeat operation.
Another significant advantage of deep brain stimulation relates to future treatments. Destructive surgery such as pallidotomy may reduce the patient’s potential to benefit from future therapies. For example, future brain cell transplantation may be of great help to patients with Parkinson’s disease. There is concern that a pallidotomy may prevent patients from benefiting from brain cell transplantation. This would not be the case with deep brain stimulation as the stimulator could be turned off.
Because the right side of the brain controls the left side of the body and the left side of the brain controls the right side of the body, a stimulator will help only on the opposite side of the body. Most patients will have the stimulator placed in only one side of the brain; a few will have stimulators placed on both sides but not at the same time. The risks for complications increase when stimulators are place in both sides of the brain.
In Parkinson’s disease, the goals of deep brain stimulation are to (1) improve the speed and dexterity of the arm on the side opposite to the stimulator, (2) to reduce tremor, and (3) to block the involuntary movements (called dyskinesia) associated with the medications used to treat Parkinson’s disease. Neither deep brain stimulation nor pallidotomy help problems related to walking or balance.
Deep brains stimulation should not be considered if medication can give satisfactory control of your condition. However, surgery can be considered for people who do not achieve satisfactory control through medications.
There is evidence that deep brain stimulation is as effective as or more effective than the older pallidotomy, which is a well established and accepted treatment. However, deep brain stimulation may be safer. Patients who fail to achieve satisfactory control with medications, by which is meant being able to do the things that make them happy, may consider deep brain stimulation.
If you are considering or want to know more about deep brain stimulation, go to the Medline Plus website in our First Resources section. Search the term “Parkinson’s”, and look at the article “Deep Brain Stimulation for Movement Disorders (Cleveland Clinic Foundation)”.
OTHER THERAPIES
OCCUPATIONAL THERAPY AND PHYSIOTHERAPY can help a great deal in managing Parkinson’s by assisting with movement and providing help and techniques to maintain independence in everyday life. Speech and Language Therapists can be very helpful with communication or swallowing difficulties.
PARKINSON’S DISEASE NURSE SPECIALISTS (PDNS) work with patients to understand their requirements and take control of their condition from diagnosis onwards. For example, they provide clinical monitoring and medication adjustment, are a continuous point of contact for support and are a reliable source of information for patients and carers alike.
