Ask an Expert: Medication for Parkinson's

Dr. Martin McKeown is a clinical neurologist with an interest in Movement Disorders, particularly Parkinson's disease. The unique combination of his medical training and engineering background is reflected in his research where engineering principles are applied in investigating disease mechanisms and potential treatments.

What types of medications are used for treating Parkinson’s disease?

Since the main biochemical abnormality in Parkinson’s is reduced dopamine, most medications attempt to normalize this deficit. Levodopa (L-dopa) medication, often combined with carbidopa to prevent gut upset, will ultimately be used by almost all patients. It is converted in the brain to the naturally occurring brain chemical dopamine. Since this medication was introduced over 50 years ago, we are very familiar with its pros and cons. While not perfect, it is an excellent treatment and quite safe to use.

There are also medications that can prevent dopamine from being used up too quickly and synthetic forms of dopamine (dopamine agonists) that try to improve on some aspects of L-dopa – but they have their own unique side effects.

Generally, a variety of medications can be used to treat many of the issues that may occur in Parkinson’s, including dyskinesias, memory difficulties, depression and low blood pressure when standing up.

Do these medications stop the progression of the disease?

The best way we know to slow the progression of the disease is exercise. However, it is currently unclear what type of exercise is best – likely the exercise must be sufficiently vigorous to make you sweat. Since medications like L-dopa make it easier to exercise, they may indirectly contribute to slowing the disease. There was some preliminary evidence that rasagiline (“Azilect”) may slow the progression of the disease, although this is controversial.

Incidentally, years ago there was a theoretical concern that medications like L-dopa may actually speed up the disease while merely treating the symptoms. Fortunately, this has clearly been shown not to be the case. As mentioned earlier, we have such extensive experience with L-dopa that we can say with some authority it does not negatively affect disease progression. However, this notion is still held by many in the community and may contribute to “L-dopa phobia” which may prevent people from taking medication.

What are the common side-effects of these medications?

Medications for PD are usually well-tolerated. The most common side effect being stomach upset, and this is usually best managed by slowly initiating therapy. After someone has been on L-dopa for years, they may experience dyskinesias, or involuntary movements, when they have too much medication. Based on animal studies, we believe that this can be prevented by taking smaller, but more frequent doses, as this reflects the more natural state of dopamine.

Dopamine agonists may have a range of side effects including decreased blood pressure, excessive sleepiness, swelling of ankles and cognitive changes. More recently, the dopamine agonists have been shown to make some people more impulsive. This can result in pathological gambling, hypersexuality, excessive shopping, etc. However, dopamine agonists often have a positive effect on mood.

Dosing, more frequently, is a bit less convenient; however, I believe we are seeing fewer and less severe dyskinesias than in the past. Often people confuse effects of the disease with side effects of the medication. For example, constipation is a characteristic of Parkinson’s and not normally a side effect of the medication, but sometimes people will attribute their constipation to a medication side effect.

Will the medication treat all my symptoms?

The effects medications have tend to vary by the individual. In the early stages of the disease, medications like L-dopa can almost normalize function, but tremor can be difficult to treat. However, people with tremor can take comfort in the fact that tremor is often associated with a milder form of the disease.

As people live with the disease longer, they may find that newer symptoms may not be improved with mediation. For example, loss of balance does not typically improve with medication. Finding the right dosage and combination of your medications for your specific situation is vital. Working with your neurologist and your healthcare team is essential to finding the best medications and routine for your treatment.

Are there medications to treat the non-motor symptoms of Parkinson’s?

There are many medications that can be used to treat some of the non-motor symptoms such as excessive sleepiness, bladder difficulties, restless legs syndrome, sleeping difficulties, depression, anxiety, low blood pressure on standing up, dementia, constipation, sexual dysfunction, psychosis, painful dystonia, swallowing difficulties and drooling. Treatments for these symptoms are best discussed with your doctor and/or neurologist.

Are there any natural treatments for Parkinson’s disease?

• Exercise is probably the best natural treatment. You may find tai chi, dance or medication to be helpful.
• Melatonin is often useful for sleep.
• Mucuna Pruriens or velvet bean contains L-dopa, but it has no carbidopa to assist with nausea. It is also harder to maintain a stable dosage, as the amount of L-dopa may vary from plant to plant – thus it is probably better to use the purified form available in the tablets.
• CoEnzyme Q10 is expensive, and a recent study had to be stopped prematurely because there was no significant effect.
• There is some suggestion that people with Parkinson’s may be deficient in vitamin D, vitamin B6 and B12 and so replacing these is probably warranted.
• Caffeine may also help some aspects of Parkinson’s.
• Recent studies have suggested that gut bacteria are altered in people with Parkinson’s, suggesting a potential role for probiotic-type treatments in the future.
• Many people report improvements in their symptoms after retiring, vacationing in warm climates and even travelling to places at higher altitudes.

How should I take my medication? With or without food? Should I avoid protein in my diet?

We have found that people who take their medication consistently and on time tend to do better in the long term. The issue with food can be confusing. Because early on in the disease mild nausea can be a common complaint, and medication is absorbed past the stomach, we often suggest taking the medication with food. However, protein can interfere with the medicine getting into the brain. We therefore suggest that people take the medication at least one hour before/after major meals, and with a light snack such as a cracker or a piece of fruit. You may also consider taking it with some ginger tea or sparkling water.

What other treatments are effective for treating Parkinson’s disease?

Deep Brain Stimulation (DBS) can be a very effective treatment for Parkinson’s disease, but not all subjects are suitable for surgical treatment, and DBS is invasive. In some cases where dystonia results in painful cramping of the muscles, some relief can be obtained by injection of botulinum toxin. We are currently investigating novel treatments, such as neurobiofeedback, and non-invasive brain stimulation which may prove helpful.

What kind of exercise should I do?

Any exercise is better than no exercise and can help in improving Parkinson’s symptoms as well as overall well-being. Examples of exercises that you can consider are walking, cycling, dancing, swimming, tai chi, yoga, aerobic exercise and cardiovascular exercise. Consider seeing a physiotherapist who has training in working with PD to set you up with a well-suited, personalized exercise routine.

How do I motivate myself to exercise if I experience symptoms of depression, apathy and anxiety?

It can be difficult to find the motivation to exercise especially if you are dealing with changes in mood. It can help to find something that you enjoy, or used to enjoy, and then set a goal you work towards achieving. If you’re still finding it challenging to motivate yourself, try signing up for a class at your local community centre and/or enlisting the support of a partner or friend. There are several Parkinson’s specific exercises classes throughout BC and getting involved in them will not only help your Parkinson’s symptoms but ease your symptoms of depression, apathy and anxiety as well. Depression and anxiety can often be effectively treated with medications, so you should consult your physician to see if could benefit from this therapy.

This content was published in the Summer 2015 edition of our quarterly magazine, Viewpoints. The content was accurate as of this publication date.