Drug Interactions: When The Herb Can Be Harmful

By: Angie Roullier

Cannabis does have drug interactions. Please understand this statement. We have been so conditioned to leaving this up to our doctors and pharmacists that most of us will not take the time to look into it ourselves. We most definitely do not have this luxury when it comes

to cannabis. This interaction can cause a drug to be far less or way more potent than intended, and it is up to personal responsibility to ensure you are doing everything

you can to protect yourself.

A very basic way to know if your current (and future) pharmaceuticals will have

an interaction with cannabis is to watch for a “grapefruit warning” on your pill bottles.

This sour citrus dances with the same metabolizing liver enzyme that we had

spoken about earlier in regard to edibles. “Grapefruit juice decreases the activity

of the cytochrome P450 3A4 (CYP3A4) enzymes that are responsible for breaking

down many drugs and toxins.”111 Some may think that you would have to drink

gallons of the stuff in order for it to have an effect. Think again.

“One whole fruit or 200 milliliters of grapefruit juice (a bit less than one cup) can

block the CYP3A4 enzymes and lead to toxic blood levels of the drug.”112 Blood thinners and medications for epilepsy are famous for having this warning attached to their bottles.

Let’s say that you have been taking the same drug for years to keep your seizures at bay, and it’s working, but you would like to try to introduce cannabis into your healthcare regimen. The very last thing you want is to start having seizures again because you didn’t do your due diligence. It would also be wise to ask your doctor if any newly proposed medications carry this warning prior to them prescribing it. The conversation could go something like this: “I would like to start you on ABC medication for your migraines,” your doctor says. You can respond with, “Does ABC come with a grapefruit warning? I use CBD and I know it carries the same warnings as a grapefruit interaction.” If your new medication has just phoned into the pharmacy, be sure to ask the same question so everyone is on the same page.

There is an available search engine to check if a certain medication interacts

with cannabis. I have not been given permission to add the actual link, so I will tell

you to search Penn State’s website (wink).

111https://www.drugs.com/article/grapefruit-drug-interactions.html

112https://www.drugs.com/article/grapefruit-drug-interactions.html