04. Medical Cannabis in the Treatment of Parkinson’s Disease

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Hello. I am Dr. Greg Pontone, speaking on behalf of the Psychopharmacology Institute. Today, I shall be discussing an article by Traci Aladeen on the utilization of medical cannabis in the management of Parkinson’s disease. This article explores the potential impact of medical cannabis on symptomatic relief for individuals afflicted with Parkinson’s disease.

The prevalence of Parkinson’s disease is on the rise, and although dopamine-based therapies offer some alleviation for motor symptoms, alternatives are limited, with even fewer options for the treatment of nonmotor symptoms. The authors of the article in question suggest that medical cannabis could enhance both motor and nonmotor symptom management in patients with Parkinson’s disease.

This paper is a retrospective study of patients registered under the New York State Medical Cannabis Program. It is not a randomized controlled trial and does not compare medical cannabis with placebo, nor does it prospectively control for other factors. The study cannot recommend dosages or formulations for medical cannabis due to potential variability in formulations from different dispensaries and variability in how patients self-administer those formulations. However, it systematically investigates the symptomatic changes, adverse events, and concurrent medication changes that may be relevant to the use of medical cannabis in people with Parkinson’s disease.

The study included 69 eligible patients. Fifteen out of these 69 patients discontinued medical cannabis before the study’s conclusion, with lack of efficacy being the most common reason for discontinuation. Only 4 individuals discontinued due to an adverse event. Although 48% of the Parkinson’s patients on medical cannabis experienced at least 1 adverse event, none reported a severe adverse event. Somnolence or fatigue were the most common, followed, in order of decreasing incidence, by confusion or cognitive impairment, dizziness, anxiety, euphoria, vision changes, and a few instances of hallucinations or delusions.

An improvement in at least 1 Parkinson’s associated symptom was reported by 87% of patients after initiating medical cannabis treatment. On the motor side, these included symptoms such as tremor, gait disturbance, rigidity, bradykinesia, dystonia, and dyskinesia. Nonmotor symptoms, such as pain, sleep disturbances, depression, and anxiety, often improved. However, 28% of the sample reported a worsening of at least 1 of these symptoms, with some patients noting a mixed response—some administrations provided relief, whereas others resulted in worsening.

Intriguingly, monitoring changes in concomitant medication revealed that of the patients taking opioids at baseline—which was about 25—over half either discontinued or reduced opioid use during medical cannabis treatment. There was also a trend toward reduction in benzodiazepine and muscle relaxant use, but these did not reach statistical significance.

The most commonly recommended initial formulation of medical cannabis was an oral tincture with a 1-to-1 ratio of THC to CBD, with a maximum daily dose of 14 mg ± 5 mg.

In conclusion, this retrospective chart review evaluated the real-world impact of medical cannabis on Parkinson’s symptoms. Improvement in at least 1 symptom was reported by 87% of patients. Both motor and nonmotor symptoms appeared equally likely to improve. However, at least 1 symptom worsened in 28% of patients. Adverse events, although common (occurring in about half of the sample), were not severe, suggesting that medical cannabis was generally well-tolerated. Consistent with other studies on medical cannabis in Parkinson’s, 56% of opioid users in the study managed to reduce or discontinue their opioid use during medical cannabis treatment—a potential benefit, as opioids can exacerbate issues such as falls, confusion, sedation, and constipation in patients with Parkinson’s. Although the current study’s results are insufficient to establish an evidence-based prescription of medical cannabis, they do offer significant insights into potential risks and benefits to assist in managing patients who may opt for this alternative treatment.

Abstract

Medical Cannabis in the Treatment of Parkinson’s Disease

Traci S Aladeen, Anna G Mattle, Kory Zelen, Moustafa Mesha, Michelle M Rainka, Tanya Geist, Bennett Myers, Laszlo Mechtler

Objectives: Medical cannabis (MC) has recently garnered interest as a potential treatment for neurologic diseases, including Parkinson’s disease (PD). A retrospective chart review was conducted to explore the impact of MC on the symptomatic treatment of patients with PD.

Methods: Patients with PD treated with MC in the normal course of clinical practice were included (n = 69). Data collected from patient charts included MC ratio/formulation changes, PD symptom changes after initiation of MC, and adverse events (AEs) from MC use. Information regarding changes in concomitant medications after MC initiation, including opioids, benzodiazepines, muscle relaxants, and PD medications, was also collected.

Results: Most patients were initially certified for a 1:1 (∆ 9 -tetrahydrocannabinol:cannabidiol) tincture. Eight-seven percent of patients (n = 60) were noted to exhibit an improvement in any PD symptom after starting MC. Symptoms with the highest incidence of improvement included cramping/dystonia, pain, spasticity, lack of appetite, dyskinesia, and tremor. After starting MC, 56% of opioid users (n = 14) were able to decrease or discontinue opioid use with an average daily morphine milligram equivalent change from 31 at baseline to 22 at the last follow-up visit. The MC was well-tolerated with no severe AEs reported and low rate of MC discontinuation due to AEs (n = 4).

Conclusions: The MC may improve motor and nonmotor symptoms in patients with PD and may allow for reduction of concomitant opioid medication use. Large, placebo-controlled, randomized studies of MC use in patients with PD are required.

Reference

Aladeen, T. S., Mattle, A. G., Zelen, K., Mesha, M., Rainka, M. M., Geist, T., Myers, B., & Mechtler, L. (2023).

Medical cannabis in the treatment of Parkinson’s Disease

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Clinical Neuropharmacology, 46

(3), 98–104.