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A drug interaction can occur when two drugs react with one another. When this happens, the individual taking the two drugs may experience a stronger effect from either drug, or a weaker effect from the first drug, usually called the “object drug.” It can also increase or decrease the side effects from the “object drug” by increasing or decreasing the amount of the drug in the bloodstream.
These reactions are called “pharmacokinetic.” How much of the drug is in the body and the body’s response to the drug is what causes a pharmacokinetic interaction.
All pharmaceuticals are modified, detoxified and removed from the body by metabolic enzymes.
Metabolic enzymes are responsible for proper digestion, breathing, cellular energy, and many other life-sustaining functions. When metabolic pathways are dysregulated, diseases such as obesity, diabetes, hormonal imbalance, cancer, high blood pressure and osteoporosis, are prevalent.
One family of metabolic enzymes that metabolizes nearly 60% of all medications is known as Cytochrome P450. These enzymes are mostly found in the liver, though they can also be located in the intestines, in the lungs and in other parts of the body. As it turns out, the primary metabolic enzymes that break down CBD also come from the same P450 family and are known as CYP3A4 and CYP2C19.
Prescription drugs that are also broken down by those enzymes and follow the same metabolic pathway, can be affected by ingested CBD. This is very similar to the grapefruit warnings you may have seen on certain medicines. What CBD and grapefruit have in common is that they both bind with and neutralize the CYP450 enzymes in the gut, though grapefruit is known to have a much stronger effect.
This can cause an increase or decrease of the medications in the body, because the ingested CBD is changing the amount of the metabolic enzymes present. According to the District of Columbia Department of Health, CBD can increase the amount of medication in your blood.
How intensely this all plays out in your body mainly depends on the dosage of both the medication and the CBD that you’re taking, according to Yasmin Hurd, director of the Addiction Institute at the Icahn School of Medicine at Mount Sinai. “If the concentration of CBD is high enough, it could inhibit the activity of those enzymes, so you would end up with more of the other drug getting into your system,” she added. “On the flip side, very low amounts of CBD don’t seem to have that much of an effect on how well your body processes other medications.”
Drug interactions with CBD usually simply require an adjustment of the amount of CBD or in some cases, permission from your doctor to modify the amount of the prescription medication, if possible. That’s because these interactions may actually be a positive occurrence, because they may enhance the effect of the pharmaceutical requiring less of it.
Some people are more sensitive than others. Some of the factors that contribute to how different people’s bodies respond to certain medications can be significantly influenced by age, weight and genetics.
According to many studies, CBD has been found to be safe and well-tolerated.
However, bear in mind that if you drink alcohol or take prescription drugs for anxiety or depression, CBD can inhibit the enzymes that metabolize these drugs. In consultation with your doctor, your physician may reduce the amount of medication necessary to offset this action.
The metabolic enzymes that CBD could potentially degrade are in the liver. Dr. Michelle Henry, a board-certified Harvard-trained surgeon, suggests that when you take CBD orally, it then goes through your gastrointestinal system and some of the absorption is reduced, thus lowering the likelihood of an interaction.
According to Dr. Henry, applying CBD topically carries almost zero risk because the skin provides the least likely route for CBD to get into the bloodstream. When you apply CBD as a cream (for pain relief or skin-care), it’s highly unlikely to cause any kind of interaction with medication.
The University of Alabama published an interesting case study describing a case where a patient was on Coumadin (a blood thinner). Coumadin is known to cause adverse drug reactions.
In fact, among adults 65 years and older, Coumadin (also known as Warfarin) was one of the 15 most common drugs responsible for an estimated 60 percent of the emergency room visits for adverse drug events.
The doctor was able to reduce the Coumadin dose when the patient also began to use CBD (Cannabidiol). Because CBD acts as an inhibitor of the CYP2C9 and CYP34A enzymes that metabolize Coumadin, the patient ended up needing less Coumadin (only 70% of the original dose).
Are There Any Known Drug Interactions with CBD?
The following prescription medications are metabolized by the CYP family of enzymes. If you are taking a drug listed below, let your doctor know that you will be also taking full spectrum CBD. Because CBD is being metabolized by the same enzymes, it is possible that you may need less of the prescription or over-the-counter medication than you may otherwise require.
That’s great news. CBD can help you to reduce the amount of medication you are taking, so you have fewer side effects from your meds and you save money. Please work with your doctor when you make any changes to your prescription medication intake.
DRUGS | BRANDS | CONDITION TREATED |
Alprazolam | Xanax | Anxiety |
Aprepitant | Emend | Nausea and Vomiting from Chemotherapy |
Baclofen | Lioresal, Gablofen | Muscle Spasms |
Buprenorphine | Belbuca, Probuphine, Buprenex and Butran | Severe Pain |
Busiprone | Anxiolytic | Anxiety |
Carbamazepine | Tegretol, Equetro & others | Seizures, Nerve Pain, Bipolar |
Citalopram | Celexa | Depression |
Clonazepam | Klonopin | Seizures, Panic Disorder, Anxiety |
Clopidogrel | Restasis, Sandimmune | Organ Transplant Rejection (prevention) |
Cyclobenzaprine | Amrix, Fexmid | Muscle Relaxant |
Cyclophosphamide | Cytoxan | Cancer including Lymphomas and Leukemia |
Cyclosporine | Restasis, Sandimmune | Organ Transplant Rejection (prevention) |
Dexamethasone | Ozurdex, DexPak | Eye Swelling |
Dextromethorphan | Tussin Cough, Scot-Tussin, Diabetes DF, Robitussin ER, Tussin Maximum Strength | Cough |
Diazepam | Valium | Anxiety, Alcohol Withdrawal, Seizures |
Diphenoxylate & Atropine | Lomotil | Diarrhea |
Disulfiram | Antabuse | Alcohol Abuse or Addiction |
Dronabinol | Marinol | Nausea and Vomiting from Chemotherapy |
Duloxetine | Cymbalta | Depression; Nerve Pain |
Edaravone | Radicava | Amyotrophic Lateral Sclerosis (ALS) |
Efavirenz/emtricitabine/tenofovir disoproxil fumarate | Atripla | Human Immunodeficiency Virus (HIV) |
Elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide | Genvoya | Human Immunodeficiency Virus (HIV) |
Elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate | Stribild | Human Immunodeficiency Virus (HIV) |
Entacapone | Comtan | Parkinson’s Disease |
Escitalopram | Lexapro | Depression |
Eszopiclone | Lunestra | Insomnia |
Fentanyl | Duragesic | Severe Chronic Pain |
Fingolimod | Gilenya | Multiple Sclerosis (MS) |
Fluoxetine | Prozac | Depression |
Gabapentin | Neurontin | Seizures and Pain caused by Shingles |
Galantamine | Razadyne | Dementia |
Granisetron | Sustol | Nausea and Vomiting from Chemotherapy |
Haloperidol | Haldol | Antipsychotic |
Hydrocodone | Vicodin | Moderate to Severe Pain |
Hydroxyzine | Histamine | Allergies |
Isocarboxazid | Marplan | Depression |
Levetiracetam | Roweepra, Keppra | Seizures |
Lorazepam | Ativan | Anxiety, Seizures |
Losartan | Cozaar | High Blood Pressure |
Meloxicam | Mobic, Viviodex | Osteoarthritis (OA) and Rheumatoid Arthritis (RA) |
Methadone | Diskets, Methadone Intensol, Methadose and Dolohine | Pain, Addiction to Opioids |
Nabilone | Cesamet | Nausea and Vomiting from Chemotherapy |
Nortriptyline | Pamela | Depression, Nerve Pain |
Olanzapine | Zyprexa | Antipsychotic |
Ondansetron | Zofran | Nausea and Vomiting from Chemotherapy |
Oxcarbazepine | Roxicodone, Xtampza, Oxaydo | Moderate to Severe Pain |
Oxycodone | Roxicodone, Xtampza, Oxaydo | Moderate to Severe Pain |
Palonosetron | Aloxi | Nausea and Vomiting from Chemotherapy |
Phenelzine | Nardil | Depression |
Predinisone | Deltsone, Rayos | Inflammation, arthritis, eye disease, immune system disorders, skin diseases, blood disorders, cancer, allergies, breathing problems |
Pregabalin | Lyrica | Nerve pain, muscle pain, fibromyalgia |
Propranolol | Inderal LA or XL, Hemangeol | High Blood Pressure, Chest Pain, Tremors, Migraines |
Quetiapine | Seroquel XR and Seroquel | Antipsychotic |
Rifaximin | Xifaxan | Irritable Bowel Sydrome, Diarrhea |
Riluzole | Rilutek | Amyotrophic Lateral Sclerosis (ALS) Also known as Lou Gehrig’s Disease |
Risperidone | Risperdal | Schizophrenia, bipolar disorder, irritability in autism. |
Ropinirole | Requip | Parkinson’s Disease, Restless Leg Syndrome |
Rosuvastatin | Crestor | High Cholesterol |
Selegiline | Eldepryl, Zelapar | Depression |
Sertraline | Zoloft | Depression |
Siponimod | Mayzent | Multiple Sclerosis (MS) |
Temazepam | Restoril | Insomnia |
Tetrabenazine | Xenazine | Huntington’s Disease |
Tolcapone | Tasmar | Parkinson’s Disease |
Topiramate | Trokendi XR, Qudexy XR, Topomax | Seizures; Migraine headaches |
Tramadol | Ultram | Pain Reliever |
Tranylcpromine | Parnate | Depression |
Trazodone | Desyrel | Insomnia |
Venlafaxine | Effexor | Depression |
Warfarin | Coumadin | Blood Clots |
Zolpidem | Ambien | Insomnia |
A thorough list of herbs and pharmaceutical drugs that are metabolized by the CYP family of enzymes can be found here.
I hope you found this information helpful. This information on the interaction of prescription drugs with CBD and any risks, is an excerpt from my recently released book: CBD for Health & Wellness: Questions You Should Be Asking. For a limited time, you can get the book free here: RenasOrganic.com/book

Get CBD for Health & Wellness: Questions You Should be Asking
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I have been dedicated to helping people achieve health–mental, physical and emotional health and wellness, since 1990. I am honored that my wellness program has been reviewed and sponsored in over 75 hospitals. Thank you for stopping by and I hope that my message can help you and your loved ones.
To Your Health & Happiness, Rena