Update on marijuana in Parkinson disease

Medical marijuana has been a daily topic raised by Parkinson disease (PD) patients in my clinic for the last several years.   This is not surprising in a state with medical marijuana laws going back to 1998.  Often overlooked is the fact that under state law PD is not an indication for medical marijuana.  For those reasons in the winter 2016/2017 issue of MPDN the topic was discussed (1).   At the time I noted reliable scientific studies were limited, though the field, so to speak, was growing.   Although now 31 states and the District of Columbia have some form of medical marijuana law, it is still illegal at the federal level, and classified as a Schedule I substance.  The scheduling system is described by the Drug Enforcement Agency (DEA) as follows (2):

“Drugs, substances, and certain chemicals used to make drugs are classified into five (5) distinct categories or schedules depending upon the drug’s acceptable medical use and the drug’s abuse or dependency potential. The abuse rate is a determinate factor in the scheduling of the drug…”

The DEA goes on to say that

Schedule I drugs, substances, or chemicals are defined as drugs with no currently accepted medical use and a high potential for abuse. Some examples of Schedule I drugs are: heroin, lysergic acid diethylamide (LSD), marijuana (cannabis), 3,4-methylenedioxymethamphetamine (ecstasy), methaqualone, and peyote”.

Many in law and medicine have contested this Schedule I status for marijuana, though the discussion is far from over and the tide is moving forward.  Two countries: Uraguay and Canada have decriminalized marijuana, and many countries the world over are pursuing marijuana as a therapeutic, some of whom  such as Germany, have medical marijuana laws.  Research into medical applications of marijuana and its components is happening around the world, and PD is included among the potential therapeutic targets, though others are paving the way even faster.

In June of this year the Food and Drug Administration (FDA) approved a new drug to treat a severe form of seizures.

The drug Epidolex, is the first drug containing a purified form of a cannabidiol (CBD). 

CBD is a type of molecule in marijuana (footnote).  On the same date FDA Commissioner Scott Gottlieb, M.D. issued a statement on the importance of proper research to prove safe and effective medical uses for the components of marijuana (3).

He noted that over the prior decade the FDA had

“seen a growing interest in the development of therapies derived from marijuana and its components” for “a wide number of medical conditions.” 

Dr. Gottlieb reported that the FDA has been supportive of research in this area for many years, though marijuana is a Schedule I compound with known risks.  Therefore, he argued research with marijuana or its components should be held to the same standard as other drug compounds, especially in light of the fact that some proponents of medical marijuana use had called for a lower standard.

Nonetheless, “the FDA has an active program to assist drug developers who want to investigate marijuana or its components through properly controlled clinical trials, to demonstrate the potential for safe and effective uses.” 

To further development in this area the FDA has formed a Botanicals Team to provide scientific expertise on botanical issues for researchers developing drugs derived from plants, such as marijuana.

And, the FDA is not the only federal agency relaxing its stance on marijuana, or at least some components of the plant.  The DEA has rescheduled the epilepsy CBD drug Epidolex from Schedule I to Schedule V, which is the lowest degree of restriction:

“Schedule V drugs, substances, or chemicals are defined as drugs with lower potential for abuse than Schedule IV and consist of preparations containing limited quantities of certain narcotics. Schedule V drugs are generally used for antidiarrheal, antitussive, and analgesic purposes. Some examples of Schedule V drugs are: cough preparations with less than 200 milligrams of codeine or per 100 milliliters (Robitussin AC), Lomotil, Motofen, Lyrica, Parepectolin.”

This new scheduling likely opens the door to other cannabis-based medications. However, the DEA was clear that the rescheduling was only for this specific product.

Footnote: There are many different CBD molecules, see the article in reference 1.

REFERENCES

1.What about medical marijuana and PD? https://mainepdnews.org/2017/01/03/what-about-medical-marijuana-and-pd/

2. Drug Scheduling https://www.dea.gov/drug-scheduling

3. Statement by FDA Commissioner Scott Gottlieb, M.D., on the importance of conducting proper research to prove safe and effective medical uses for the active chemicals in marijuana and its components https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm611047.htm

Published by

Bill Stamey, M.D.

A neurologist trained in movement disorders, Dr. Stamey has no relevant financial or nonfinancial relationships to disclose. His artistic rendering is by Emily Stamey. Maine PD News receives no outside funding. www.mainepdnews.org