With medical marijuana now legalised in 32 states, Washington, DC, it is clear that there will be strong interest in its therapeutic properties. Researchers are testing medical marijuana, which is also called cannabis, as a treatment for many illnesses and diseases, including neurological conditions, with Parkinson’s disease (PD) high on the list. But despite several clinical tests, it has not been demonstrated that cannabis can directly benefit people with PD.
The Science Behind Marijuana
What is the science and pharmacology behind medical marijuana, and can it be used to treat Parkinson’s manifestation?
The endocannabinoid system is located in the brain and made up of cannabinoid receptors (a receptor is molecular switch on the outside of a cell that makes something happen inside a cell when activated) that are linked to neurons (brain cells) that regulate thinking and some body functions.
Researchers began to show enthusiasm to study cannabis in relation to PD after people with PD gave anecdotal reports and posted on social media as to how cannabis allegedly reduced their tremors. Few researchers assume that cannabis might be neuroprotective— saving neurons from damage caused by PD.
Cannabinoids (the drug molecules in marijuana) have also been studied for use in treating other symptoms, like bradykinesia (slowness caused by PD) and dyskinesia (excess movement caused by levodopa). Despite some promising preclinical findings, researchers have not found any essential or conclusive benefits of cannabis for people with PD.
Researchers points caution for people with PD who use cannabis because of its effect on thinking. PD can diminish the executive function — the ability to make plans and limit risky behavior. Person with a medical condition that impairs executive function should be cautious about adopting any medication that can compound this effect.
MOTOR SYMPTOMS OF PARKINSON’S INCLUDE THE FOLLOWING:
- Tremor (shaking)
- Slowed movement
- Muscle rigidity
- Loss of automatic movements
- Speech changes
- Impaired balance and posture.
NON-MOTOR OF PD ARE VARIOUS AND MAY INCLUDE THE FOLLOWING:
- Cognitive impairment
- Low blood pressure
- Restless leg syndrome
- Sleep disturbances.
Parkinson’s is a highly personalised disease. The associated symptoms, life impact, and progression often differ from person to person.
Optimum dosing that achieves efficacy while minimizing adverse effects remains to be established. Current information might not be generalizable to the individual need of each patient. Single case reports support cannabis as a therapeutic agent.Topical and oral cannabinoids are optimally provided in solvents due to their lipophilic nature. Starting at low dosages in cannabis-naïve individuals and utilizing slow increases in dosage help minimize adverse consequences. Clinical efficacy in patients with PD is directed toward bradykinesia, stiffness, rigidity, and tremors, which is mediated by nigrostriatal neurons.
Risks and Benefits for People with PD
There are danger and gain associated with the use of cannabis for people with PD. Gain includes a possible improvement in anxiety, pain management, sleep dysfunction, weight loss and nausea. Potential adverse effects include: impaired cognition (impairment in executive function), dizziness, blurred vision, mood and behavioural changes, loss of balance and hallucinations. Chronic practice of marijuana can increase risk of emotion disorders and lung cancer.
Marijuana has been shown to attenuate motor and non motor signs and symptoms of PD. However, there are limitations to the available research, including small sample sizes and lack of standardised clinical outcome measures. Neurologic manifestations of PD might be alleviated with cannabis products, but such assertions are yet be established in reference to patient-specific factors, such as disease stage, target symptoms, and earlier levodopa exposure, and dosages of cannabis product have yet to be established. Further research will reveal the efficacy and safety of medical marijuana for patients with motor manifestations of Parkinsonism. Till then, pharmacotherapy with cannabis should be considered and applied with caution.