This interaction is more theoretical than evidence based as there are a lack of studies that have reported this interaction. In addition, there is some controversy in regard to just how much, if at all, CBD can inhibit metabolizing enzymes.
The doses of CBD used in studies that have shown potential interactions ranges widely. While most over the counter CBD products range from 1mg to 10mg per serving, studies have used anywhere from 100mg to 600mg! There is a good chance the more commonly used lower doses of CBD don’t have significant interactions at all, but more studies are needed.
However, hydrocodone is metabolized in the body by CYP 2D6 to hydromorphone, which is significantly more potent than hydrocodone and mainly responsible for the analgesic effects of the drug. Therefore, potential metabolism inhibition by CBD could theoretically decrease the effectiveness of hydrocodone (due to less conversion to hydromorphone).
Taking Hydrocodone With CBD (Cannabidiol)
Cannabidiol (CBD) is a major constituent of the cannabis plant and is considered “non-psychoactive”, unlike delta-9-tetrahydrocannabinol (THC). In fact, depending on the variety of cannabis, CBD can make up close to 40% of cannabis extracts according to studies.
However, there is a theoretical interaction between CBD and hydrocodone where the effectiveness of hydrocodone in relieving pain could be decreased.
Respiratory depression is one of the most dangerous adverse effects of high doses of opioids and drug interactions with opioids, like hydrocodone. Fortunately, CBD, and other constituents of marijuana, do not appear to depress respiration to any significant degree, if at all.
Studies have shown that CBD can inhibit:
CBD has the potential to interact with many other products, including over-the-counter medications, herbal products, and prescription medications. Some medications should never be taken with CBD; the use of other medications may need to be modified or reduced to prevent serious issues. The consequences of drug interactions also depend on many other factors, including the dose of CBD, the dose of another medication, and a person’s underlying health condition. Older adults are more susceptible to drug interactions because they often take multiple medications, and because of age-related physiological changes that affect how our bodies process medications.
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.
The bottom line: Talk to your doctor or pharmacist if using or considering CBD
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.
The researchers further warned that while the list may be used as a starting point to identify potential drug interactions with marijuana or CBD oil, plant-derived cannabinoid products may deliver highly variable cannabinoid concentrations (unlike the FDA-regulated prescription cannabinoid medications previously mentioned), and may contain many other compounds that can increase the risk of unintended drug interactions.
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.