Which medicines should not be taken with CBD?

Cannabis is a complex plant, with hundreds of chemicals and over 100 distinct cannabinoids. The limited research into cannabidiol or CBD, the second most common cannabinoid in cannabis, shows signs of potential health benefits across a wide range of conditions. However, as CBD becomes more common, a key question comes to mind: «How will CBD interact with my current medications?»

Currently, scattered research suggests that CBD may cause problematic interactions with certain prescription drugs. The results are far from conclusive - more research is still needed on the interaction of CBD with different drugs. Many doctors and researchers urge people who use CBD for medical or recreational purposes to exercise caution when mixing it with other medications and to consult their doctor about possible interactions.

Interaction of CBD with drugs

If you're wondering whether CBD is dangerous, Have you heard of the grapefruit test? Many prescription drugs carry grapefruit warnings on the label, advising against consumption of this citrus fruit during treatment. Many drugs are broken down in the liver and small intestine by a group of proteins called cytochrome P450 (CYP) enzymes. It is this process that enables a drug's benefits to be delivered to its intended target.

Grapefruit disrupts CYP activity and slows down the way these proteins normally break down drugs. The fruit also increases side effects and the length of time the drug remains in the system. A 2013 study entitled «Grapefruit Medication Interactions: Forbidden Fruit or Avoidable Consequences?» published in the Canadian Medical Association Journal showed that grapefruit can increase blood content levels when interacting with at least 85 different drugs. Reported consequences were severe, including irregular heartbeat, organ failure, internal bleeding and death.

In addition, a study conducted in 1993 by pharmacology researchers at the University of California, San Francisco, published in the journal Biochemical Pharmacology, found that CBD, like grapefruit, disrupts the normal functioning of cytochrome P450 enzymes in mice. The study postulates that while this blockage may allow patients to take lower doses of their prescriptions, it may also cause a toxic accumulation of chemicals in the body. Since the publication of this study, several scientific and medical journals have published evidence of CBD's grapefruit-like effects in humans.

The type, quality and purity of CBD administered all affect how it interacts with your body and medications. The timing of when you take CBD and any other prescription medication also plays a role in how the two may interact in your body. And of course, everyone reacts differently to medications, depending on genetics, age, weight and other factors.

Should I take CBD with ibuprofen?

Ibuprofen is a non-steroidal anti-inflammatory drug (NSAID) that reduces pain and inflammation in the body. Ibuprofen carries a risk of anemia and can cause dizziness, shortness of breath and nausea.

Potentially, CBD may increase the duration and strength of ibuprofen, thereby increasing the risk of undesirable side effects. To date, no human studies have specifically examined the interaction of CBD with NSAIDs. Nevertheless, two studies conducted in animal models in 2006 and 2008 and published respectively in Bread and Pharmacology, These studies suggest that other cannabinoids may act synergistically with NSAIDs such as ibuprofen to reduce pain.

Patients should consult their healthcare professional before taking ibuprofen with CBD.

Should I take CBD with Xanax?

Xanax (generic name alprazolam) is a member of the benzodiazepine family of drugs used to treat panic disorders, anxiety and depression. Common side effects of Xanax include drowsiness, lack of coordination, memory loss and morning anxiety.

Xanax is broken down in the liver via an enzyme called CYP3A4, which is inhibited by CBD. Taking CBD could potentially increase the duration of Xanax's presence in the body and prolong or increase the likelihood of undesirable side effects. CBD could one day be considered as an alternative to Xanax, as various research studies, including a 2011 study published in Neuropsychopharmacology, have documented the cannabinoid's potential anti-anxiety properties.

No research has explicitly documented interactions between Xanax and CBD. Patients taking Xanax who are interested in CBD should talk to their doctors for more information.

Should I take CBD with statins?

Statins are a classification of drugs designed to lower cholesterol levels and protect against heart attacks and strokes. Common side effects of statins include muscle pain, increased blood sugar levels, headaches and nausea.

Statins are processed by CYP function in the liver, which CBD inhibits. Although no research has specifically investigated the interactions between statins and CBD, the cannabinoid could potentially increase the strength and duration of statins in the system and the risk of adverse side effects.

Patients taking statins should talk to their doctor before using CBD.

Drugs to avoid with CBD

CBD's documented effects on liver function and the enzymes that metabolize many drugs are relevant when considering whether or not to consume CBD with certain medications. CBD acts on the same metabolites as grapefruit - therefore, many of the prescription drugs that carry grapefruit warning labels may pose similar risks when taken with CBD.

These drug classifications include a large percentage of existing prescriptions, such as benzodiazepines, antihistamines, haloperidol, antiretrovirals, statins, cyclosporine, sildenafil, warfarin and other drugs metabolized by CYP3A4 and CYP2D6.

Clobazam, used to treat epileptic seizures, is another type of medication that may not be advisable to take at the same time as CBD. However, Epidiolex is an FDA-approved CBD-based medication that doctors can prescribe to treat epilepsy. A significant amount of data, from clinical trials, exists on Epidiolex, although the drug can also cause adverse effects, according to a 2019 study conducted by researchers at Columbia University and published in the journal F1000Research.

No research definitively warns patients against taking these medications with CBD, although the previously cited 2013 study published in the Canadian Medical Association Journal showed that grapefruit-drug interactions can lead to serious effects, including irregular heartbeat and sudden death, kidney failure and muscle damage. Each patient's case is unique, and people should talk to their healthcare providers if they're considering taking CBD in combination with specific prescription medications.

Does CBD oil affect blood pressure?

A 2017 study, A single dose of cannabidiol reduces blood pressure in healthy volunteers in a randomized crossover study«, published in JCI Insight, supports CBD's ability to reduce blood pressure. The researchers also suggest that CBD's anxiety- and stress-reducing properties may contribute to the overall ability to reduce blood pressure. However, if CBD is taken alongside blood pressure medication or beta-blockers, the two drugs could double up and lower blood pressure to unhealthy levels.

Does CBD oil thin the blood?

No research shows that CBD oil taken alone can thin the blood. CBD oil increases the effects of anticoagulant drugs, such as warfarin, and could potentially push warfarin beyond therapeutic levels, as shown in the previously cited 2017 study published in Epilepsy & Behavior Case Reports.

Does caffeine counteract CBD?

Caffeine and CBD are two substances that are gaining in popularity, especially when mixed together. Caffeine can keep sleep-deprived individuals alert and lucid. What's more, a study carried out in 2007 on rats, published in the journal Pharmacology Reports has shown that caffeine is metabolized by CYP enzymes, which CBD inhibits. This could extend the time caffeine remains in the body and has the potential to prolong caffeine's stimulant effects.

The information in this article is based on current research and should not be construed as medical advice. Please speak to your doctor or specialist if you have any questions about your medication and the use of CBD.