Drug Interactions with Cannabis-The Orlando Times

The Orlando Times

Drug Interactions with Cannabis

Think Of Pharmacists AsA Resource On Drug Interactions With Cannabis 

Editor’s note: This commentary is provided by the Medical Marijuana Education and Research Initiative (MMERI) of Florida A&M University. 



Often overlooked in conversations about medical marijuana treatments is the role of pharmacists. In Florida, your typical pharmacy cannot dispense medical cannabis and Cannabidiol (CBD) products recommended by a qualified medical marijuana physician. That’s the job of Medical Marijuana Treatment Centers (MMTC’s), which under Florida law must be owned and operated by the same company that grows and cultivates medical marijuana.  


But does such a vertically integrated business structure mean a pharmacist shouldn’t be involved in a medical marijuana patient’s treatment?  


“No,” say pharmacists Dr. Caleshia Herring and Valeria Robinson-Baker, who make a strong case for consulting members of their profession about potential drug interactions with medical marijuana and CBD products, and advise caution on dosing.   


Herring, a “master herbalist” and researcher for a medical marijuana company, has extensive training in medication management, pharmacotherapy, herbal supplementation, and alternative medicine. She’s also knowledgeable on regulatory and law updates concerning Medical Marijuana Treatment Center (MMTC’s) operational requirements and Florida patient use requirements. She holds a Doctor of Pharmacy from Florida A&M University (FAMU).   


Robinson-Baker has served as director of pharmacy at four hospitals, and she’s currently running the non-sterile compounding section and hazardous drugs program at Olympia Compounding Pharmacy in Orlando. She holds a Bachelor of Pharmacy from FAMU and serves on MMERI’s External Advisory Council. 


Both say patients should keep their primary care physicians in the loop on recommended medical marijuana treatment regimens, and they encourage talking with pharmacists about concerns over interactions with prescription medications.  


Fortunately, adds Dr. Herring, there are “very, very few major drug interactions” with the cannabis herb. “There are some, but it's not something that's going to kill you like other harsh pharmaceuticals. Marijuana has very minimal to no side effects in most users.” 


But that’s not to say cannabis treatments don’t pose some health risks. Robinson-Baker warns against using the prescription blood thinners Warfarin or Coumadin while undergoing cannabis therapies. The mixture could lead to increased bleeding, she says.  


Patients on anti-anxiety drugs and/or taking anti-depressants also should approach medical marijuana with caution, she says, because it “can either accentuate the drugs that you're taking, like Xanax [which is used to treat anxieties], or it can completely minimize or do away with the effect of the drug.” 


Dr. Herring adds alcohol and the herbal medicine St. John’s Wort to the list of substances that could negatively interact with cannabis, potentially triggering “psychiatric episodes.” 


“Those are some of the things that we as pharmacists can play a primary, actually a very integral role in your healthcare with drugs that interact with your medicinal marijuana,” says Robinson-Baker. 

While the pharmacists support the use of medical marijuana as an exit drug from addictive pharmaceuticals, they say prescription meds are still the best course of treatment for post-surgery pain management.  


“If you are having surgery and you think that smoking or ingesting marijuana is going to take your pain away; it's not going to happen,” says Dr. Herring. “It's going to be a combination of you using a pharmaceutical product and marijuana. Marijuana, it does have an indication for pain, but it's more for mild to moderate.” 


Dosing is an area of great concern with these pharmacists because, unlike prescription drugs, some medical cannabis and CBD medications lack labeling instructions. That leaves patients to resort to trial and error to find the most effective dosage, which could lead to adverse reactions.   


So, they recommend that patients whose treatments include gummies or brownies try micro-dosing at first to gauge the drugs’ impact after an hour has passed. Edibles need time to work their way through the digestive system before the full extent of their effect is felt.   


“I tend to go with the tinctures more than I do the edibles. Tinctures give you more control” with dosing, says Robinson-Baker. “Five or six drops is easy to understand, as opposed to a quarter of a brownie or one half of a brownie.” 


Dr. Herring adds that smokable medical cannabis poses the least risk of side effects.   


The pharmacists hope to see a more collaborative relationship between their industry and MMTC’s, saying it would ultimately benefit patients.  


“Currently, dispensaries have patient counseling techs, but they don't have the extensive training of a doctor, nurse or a pharmacist,” says Dr. Herring. “I would like the dispensaries to look at the pharmacist as a helper.” 


Visit bit.ly/medicineandcannabisto watch MMERI’s Conversations on Cannabis Virtual Forum on YouTube featuring Pharmacists Dr. Caleshia Herring and Valeria Robinson-Baker.  


For more information on medical marijuana and to sign up for the MMERI newsletter, go to http://mmeri.famu.edu.