What drugs should not be taken with CBD?

Dr Christian Jessen Answers your Questions

British media doctor and health campaigner, Dr Christian Jessen answer your CBD questions. In this video you will find out ‘What drugs should not be taken with CBD?’ and other fundamentals about the compound found in medical cannabis.

DR Christian on 'What drugs should not be taken with CBD?'

It is very likely that CBD could interact with other medications, be they prescription meds or over the counter remedies. 

The exact nature of these interactions may not be fully known and so it is important to always tell your doctor about any supplements you are taking, including CBD. 

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What drugs should not be taken with CBD?

CBD Interactions: Some people who wish to try CBD are currently taking medicine for a physical or mental health problem. As a result, they may be worried about the possibility of CBD causing drug interactions. In this blog, we’ll look at which medicines should be avoided when using CBD.

Although medical cannabis products are offered as supplements in the United Kingdom, Epidyolex is the only CBD compound that has been approved as a medicine for the treatment of epileptic illnesses such Dravet syndrome and Lennox-Gastaut syndrome.

cbd capsules

CBD can interfere with other drugs

CBD may compete for or interfere with enzymes in the liver that break down many medications, resulting in too much or too little of the drug in the body, a condition known as altered concentration. As a result of the changing concentration, the medicine may stop working or raise the risk of side effects.

Notoriously difficult to predict, drug interactions can result in unpleasant and occasionally fatal consequences. For example, CBD can interact with other molecules processed in the body via enzymes such Cytochrome P-450 (CYPs), which are involved in pharmacological, chemical, and endogenous substrate metabolism.

Five prescription CBD and delta-9-tetrahydrocannabinol (THC) cannabis drugs were tested by researchers from Penn State College of Medicine [1]. This list was further whittled down to 57 drugs for which a change in concentration could be fatal.

The list includes a wide range of medications, from heart medications to antibiotics, though not all of them are likely to be affected by CBD-only products.

  • Warfarin, a popular blood thinner, had the potential to cause significant medication interactions with CBD.
  • Amiodarone, a cardiac rhythm medicine.
  • levothyroxine, a thyroid medicine.
  • clobazam, lamotrigine, and valproate, among other seizure drugs.

The grapefruit warning

Certain drugs come with a warning that anyone taking them should avoid grapefruit. This is due to grapefruit interfering with the CYP3A4 enzyme in your body which is in charge of breaking down drugs in your system.

CBD is considered to block CYP3A4 enzymes similar to grapefruit, which could result in a higher concentration of the medicine in our bodies circulation and unwanted adverse effects

Do you have any evidence of CBD?

CBD has a lot of potential. However, existing clinical trials for anxiety, insomnia, and chronic pain are so small that it is difficult to draw any firm conclusions. 

To investigate further, larger-scale human trials will be needed. The UK is currently conducting research into CBD’s effects on anxiety, psychosis, and pain management in chronic diseases. 

Research into schizophrenia and rare forms epilepsy is the most advanced. The majority of clinical trials currently apply to CBD-grade medical-grade CBD. It’s not known if commercial products have a lower concentration that can cause an effect. Importantly, there are no established dosage guidelines. 

cbd capsules by british cannabis

However, regulators have provided some guidance on the upper limit. Although some studies have shown CBD can cause liver damage if taken in higher amounts, the Food Standards Authority (FSA), says the evidence isn’t conclusive. 

The FSA recommends that adults not exceed 70 mg per day. This is unless a doctor has given their approval. This amounts to approximately 28 drops of 5% CBD. 

Which drugs should not be taken with grapefruit/CBD?

According to the NHS, the following drugs are predicted to interact with grapefruit (and therefore possibly CBD) [2]. Always speak to a medical professional before making any decisions:

  •  Drugs used to treat cancer (crizotinib, dasatinib, erlotinib, everolimus, lapatinib, nilotinib, pazopanib, sunitinib, vandetanib, vemurafenib)
  • Drugs used to treat or prevent infections (erythromycin, halofantrine, maraviroc, primaquine, quinine, rilpivirine)
  • Drugs used to treat high cholesterol (atorvastatin, lovastatin, simvastatin)
  • Drugs used to treat heart and blood vessel conditions (amiodarone, apixaban, clopidogrel, dronedarone, eplerenone, felodipine, nifedipine, quinidine, rivaroxaban, ticagrelor)
  • Drugs affecting the central nervous system (oral alfentanil, buspirone, dextromethorphan, oral fentanyl, oral ketamine, lurasidone, oxycodone, pimozide, quetiapine, triazolam, ziprasidone)
  • Drugs used to treat nausea (domperidone)
  • Immunosuppressants (cyclosporine, everolimus, sirolimus, tacrolimus)
  • Drugs used to treat urinary tract conditions (darifenacin, fesoterodine, solifenacin, silodosin, tamsulosin)

Side effects to watch out for

You should follow your doctor’s advice. If they say it’s okay for you to use CBD under their supervision and monitoring, they will advise you to monitor any potential changes or side effects, such as:

  • A decrease in the effectiveness of your medication
  • Drowsiness
  • Nausea
  • Fatigue
  • Diarrhoea
  • Appetite loss or increase
  • Weight fluctuation
cbd capsules and drugs should not be taken with cbd

Talk to your doctor

CBD may interact with a variety of different products, including over-the-counter pharmaceuticals, herbal supplements, and prescription drugs. Many other factors, such as the dose of CBD, the dose of another medication, and a person’s underlying health condition influence the outcome of drug interactions.

Because people of a certain age group often take several drugs due to age-related physiological changes, the elderly are more vulnerable to drug interactions.

People considering or using CBD products should always consult their doctor before doing so, especially if they are taking other medications or have underlying medical conditions like liver disease, kidney disease, epilepsy, heart problems, a weakened immune system, or are taking medications that can weaken the immune system (such as cancer medications).

We hope you found this blog on medicines that should not be used with CBD to be informative. As you can see, there is still a lot of study being done on this, so talk to your doctor and proceed with caution.

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