Dr. Lia Ernst, a neurologist at Oregon Health and Science University, said she knew many of her epilepsy patients took cannabis to treat their conditions, but she wanted to know more detail, so she launched a small study.

A survey found 87% of Ernst’s patients had tried cannabis as a treatment, and 82% found it helpful. But then she found that only two of the 39 respondents knew what dosage they were taking.

“Sometimes it was an amount of actual flower that they were smoking or sometimes it was an amount of oil, or a droplet or something like that,” Ernst said. “But they didn’t actually know the content of that — like exactly how much marijuana, either THC or CBD was going into their bodies.”

Ernst found men generally took more marijuana than women. And that patients over 40 were taking it once a day or less, while younger people tended to take it several times a day.

The survey was published this week in the journal Epilepsy and Behavior.

Ernst thinks doctors could help patients learn more about cannabis use. But research into cannabis is limited because the federal government regards it as a Schedule I controlled substance with no medical benefit.

Cannabis cannot be legally prescribed in Oregon, although there is a strong interest in using CBD for seizure control.

Last year, the FDA approved Epidiolex, which primarily contains CBD as a treatment for certain severe types of epilepsy, including Lennox-Gastaut syndrome and Dravet syndrome.
 
Ernst said that while patients wait for science and law to catch up with patient demand, there needs to be better communication between doctors and people living with epilepsy.

In 2018, the OHSU School of Medicine began hosting continuing medical education courses for health care professionals on cannabis. The next course is scheduled for Oct. 19.