“The manufacturer of Epidiolex was asked by the FDA to conduct more drug-drug interaction studies, so we will learn more about CBD’s interactions with other drugs in the future,” says Dr. Bemben.
CBD inhibits some enzymes in this family. This makes them break down certain drugs more slowly, which could potentially increase side effects unless your doctor adjusts the dose. On the other hand, CBD induces other enzymes in this family, which speeds the breakdown of certain drugs so they may potentially be less effective unless the dose is increased.
Are older people more at risk of CBD drug interactions?
As examples, you may experience increased side effects if CBD is used along with these drugs:
CBD (cannabidiol) is seemingly everywhere, with oils, tinctures, pills, chocolates, gummy bears, and creams available all over the internet, at national drugstore chains, and perhaps at your local farmer’s market — even if you don’t live in a state where medical or recreational marijuana is legal.
What do we know for sure about CBD’s interactions with other drugs?
“We use other therapies that cause liver injury, like nonsteroidal anti-inflammatories (NSAIDs). If liver enzymes go up in someone on methotrexate, we would generally hold the drug other than methotrexate [for example, CBD or an NSAID] to see if the enzyme levels normalize,” says Michael Weinblatt, MD, professor of medicine at Harvard Medical School in Boston.
Many drugs are broken down by enzymes in the liver, and CBD may compete for or interfere with these enzymes, leading to too much or not enough of the drug in the body, called altered concentration. The altered concentration, in turn, may lead to the medication not working, or an increased risk of side effects. Such drug interactions are usually hard to predict but can cause unpleasant and sometimes serious problems.
While generally considered safe, CBD may cause drowsiness, lightheadedness, nausea, diarrhea, dry mouth, and, in rare instances, damage to the liver. Taking CBD with other medications that have similar side effects may increase the risk of unwanted symptoms or toxicity. In other words, taking CBD at the same time with OTC or prescription medications and substances that cause sleepiness, such as opioids, benzodiazepines (such as Xanax or Ativan), antipsychotics, antidepressants, antihistamines (such as Benadryl), or alcohol may lead to increased sleepiness, fatigue, and possibly accidental falls and accidents when driving. Increased sedation and tiredness may also happen when using certain herbal supplements, such as kava, melatonin, and St. John’s wort. Taking CBD with stimulants (such as Adderall) may lead to decreased appetite, while taking it with the diabetes drug metformin or certain heartburn drugs (such as Prilosec) may increase the risk of diarrhea.
CBD can alter the effects of other drugs
Researchers from Penn State College of Medicine evaluated existing information on five prescription CBD and delta-9-tetrahydrocannabinol (THC) cannabinoid medications: antinausea medications used during cancer treatment (Marinol, Syndros, Cesamet); a medication used primarily for muscle spasms in multiple sclerosis (Sativex, which is not currently available in the US, but available in other countries); and an antiseizure medication (Epidiolex). Overall, the researchers identified 139 medications that may be affected by cannabinoids. This list was further narrowed to 57 medications, for which altered concentration can be dangerous. The list contains a variety of drugs from heart medications to antibiotics, although not all the drugs on the list may be affected by CBD-only products (some are only affected by THC). Potentially serious drug interactions with CBD included
Products containing cannabidiol (CBD) seem to be all the rage these days, promising relief from a wide range of maladies, from insomnia and hot flashes to chronic pain and seizures. Some of these claims have merit to them, while some of them are just hype. But it won’t hurt to try, right? Well, not so fast. CBD is a biologically active compound, and as such, it may also have unintended consequences. These include known side effects of CBD, but also unintended interactions with supplements, herbal products, and over-the-counter (OTC) and prescription medications.
Doubling up on side effects
Absolutely. Inhaled CBD gets into the blood the fastest, reaching high concentration within 30 minutes and increasing the risk of acute side effects. Edibles require longer time to absorb and are less likely to produce a high concentration peak, although they may eventually reach high enough levels to cause an issue or interact with other medications. Topical formulations, such as creams and lotions, may not absorb and get into the blood in sufficient amount to interact with other medications, although there is very little information on how much of CBD gets into the blood eventually. All of this is further complicated by the fact that none of these products are regulated or checked for purity, concentration, or safety.