Medical Treatment Options for Parkinson’s

Navigating the healthcare system and treatment methods available to people with Parkinson’s (PwP) can be challenging. To add to this, some medical professionals lack the knowledge and resources to guide a person with Parkinson’s through their options.

Many PwP in the earlier stages of the disease, opt to make use of non-pharmaceutical treatment options; for example, incorporating vigorous exercise, a healthy diet and effective stress management techniques into their daily lives.

As the disease progresses, further treatment may be considered. This article is intended to provide information on some of the medical treatment options available to PwP. It is important to note that this information does not replace consultation with medical professionals. Furthermore, Parkinson Society BC (PSBC) has chosen to identify drugs by their chemical names, as generic and brand names can vary between countries.

Common Pharmaceutical Options

Each individual’s experience with Parkinson’s disease is unique, and as such, there is no “one-size-fits-all” approach to treatment. As a PwP, it is important to find something that works for you. Remember, two people may have similar symptoms but be pursuing very different medication regimens, and that is alright! Below is a listing of some common Parkinson’s disease (PD) medications and their purposes:

• Carbidopa-levodopa: Widely considered to be the most effective Parkinson’s disease medication, levodopa is a dopamine precursor that can cross the blood-brain barrier and be converted to dopamine in the brain. Levodopa is broken down rapidly in the body before it crosses the bloodbrain barrier, so carbidopa is given concurrently to prevent levodopa from converting to dopamine outside of the brain. This early breakdown could lead to side effects like nausea and dizziness.
• Dopamine agonists: Mimic the action of dopamine in the brain by stimulating receptors within the brain. They often aren’t as effective as levodopa, but they typically have a longer lasting effect. They are used as a monotherapy in early PD and adjunct therapy with levodopa in advanced PD.
• Anticholinergic agents: Believed to correct an imbalance between dopamine and acetylcholine in the brain, which can help control tremor. They have limited efficacy and should not be considered as first choice drugs.
• Catechol-O-methyltransferace (COMT) inhibitors: Block an enzyme that breaks down dopamine, which can help prolong levodopa therapy.
• Monoamine oxidase-B inhibitors, also referred to as MAO-B inhibitors: Block the MAO-B enzyme, which metabolizes dopamine in the brain. This leads to increased amounts of dopamine in the brain.
• Amantadine: Enhances dopamine release by blocking glutamate, a neuro-transmitter. Often used as short-term relief for early-stage or mild Parkinson’s symptoms. (Mayo Clinic, 2018)

Duodopa

Duodopa is a gel form of levodopa and carbidopa drug combination used to treat people with Parkinson’s who have responded well to levodopa, but continue to experience severe motor fluctuations.

It requires surgery where a stoma is placed into the abdomen. A tube is then inserted through the abdomen into the intestine. A pump then delivers a steady release of the drug directly into the intestine, providing a more constant “on” time.

This treatment, which costs approximately $60,000 a year, was not publicly covered under BC PharmaCare until February 14, 2017, when a dedicated coalition of advocates, supported by Parkinson Society BC, demanded access to better care for PwP. While this was an incredible victory for the Parkinson’s community, it is important to note that there are very few patients in BC who require, and qualify for, this surgery. Selected patients who have private health insurance are required to use up their ‘lifetime’ limit before BC PharmaCare funding is provided.

The Ministry of Health is working with the Pacific Parkinson’s Research Centre, under the direction of Dr. Martin McKeown, to identify and prioritize patients for coverage of Duodopa. Dr. McKeown estimates there are only 10 to 12 patients per year that need to undergo this procedure.

Deep Brain Stimulation

Deep Brain Stimulation (DBS) is a relatively new, but common, surgical procedure whereby wires, called electrodes, are placed into the brain during surgery. The electrodes are then connected by a wire to a “pacemaker” that sits under the skin, usually in the chest. Electrical pulses, produced by the electrodes, reduce motor Parkinson’s symptoms such as stiffness, slowness and tremor. According to Dr. Honey, the DBS neurosurgeon at Vancouver Coastal Health Authority, the fact that the “pacemaker” can be adjusted in intensity to maximize symptom relief and minimize side effects is the greatest strength of this treatment option.

The surgery is best suited to individuals who have had Parkinson’s for several years, still receive benefits from medications, but experience significant “off” times and/or dyskinesia. A thorough assessment process for the surgery is required before an individual is identified as a suitable candidate.

While DBS can provide some relief from motor symptoms, there are some important considerations:

• DBS does not improve non-motor symptoms of Parkinson’s disease, such as dementia, depression, constipation, bladder dysfunction, falling, speech challenges or imbalance.
• There have been reports of cognition in PD patients worsening after DBS if the patient had a preexisting cognitive impairment, such as dementia or mild to significant cognitive dysfunction.
• People with atypical parkinsonisms, such as Lewy body dementia or progressive supranuclear palsy, typically do not respond well to the surgery.

This content was published in the Spring 2018 edition of our quarterly magazine, Viewpoints. The content was accurate as of this publication date.