By Miguel Ordoñez Reviewed by: Carles Doménech


One of the oft-asked questions in regards to health and pharmaceuticals is whether or not cannabis can be mixed with medication. It is, indeed, a valid concern to raise, especially for those who regularly take cannabidiol for whatever purpose. It is understandable that some to argue in support of it, especially when it comes to CBD oil. After all, it’s non-psychotropic and used by thousands every single day, so it should be safe, right?

Well, in case you didn't know, the cannabis plant contains over a hundred chemical compounds. Some of these compounds can react with one another, which cannot be perceived as a major health problem. But the question is, will occur an innocuous reaction when it comes to CBD interacting with other drugs?

This article should provide you with a clear answer, once and for all. Hopefully, the information will be helpful for you down the line.

Can CBD Oil Affect Medication?

Before answering this, let’s first address another important question: how exactly does CBD interact with our bodies?

There is not a simple answer, but basically: CBD interfaces with the main receptors in the endocannabinoid system—CB1 and CB2—among other molecular targets, including serotonin and vanilloid receptors. Intriguingly, CBD hinders the breakdown of certain chemicals—including anandamide—that directly affect our mood, pain perception, or some mental functions, such as memory.

In doing so, CBD is able to modify the homeostasis (dynamic balance) between our physiological systems. Therefore, the use of CBD-rich cannabis strains or CBD derivates could be beneficial for some individuals under some delimitated situations. 

However, is important to know that CBD also affects the metabolism of medications, a process that takes place primarily in the liver.

How Does the Body Metabolise CBD?

CBD's interactions with other drugs largely stem from their common metabolising process and effects produced in the cytochrome P450 system. This group of liver enzymes (isoenzymes) is mainly responsible of modifying toxins, drugs, and other substances in our system. These enzymes basically alter these substances to make them easier to eliminate from the body.

But when CBD enters the body, the liver may reduce the metabolising rate of other drugs that also rely on cytochrome P450 enzymes.

In some cases, CBD can almost completely block cytochrome P450 activity, albeit temporarily, affecting the metabolic activity of compounds found in certain drugs. So, for example, if you’re taking a powerhouse painkiller like oxycodone alongside cannabidiol (CBD), the former may linger in your system for longer and in higher concentrations than expected—which isn’t necessarily a good thing.

What can be problematic is that a drug like oxycodone is only supposed to stay in your system in determinate amounts for a certain period of time. Going beyond that duration may elicit overdoses or increase side effects like nausea and drowsiness. All of this could be an issue if you’re driving a car or operating heavy machinery. At worst, these interactions can also cause other damage to your body.

Depending on the dose and method of administration, CBD can remain in the body for about four weeks. During that time, it is stored within fatty tissues until it is gradually released in small doses back into the bloodstream. From there, cannabidiol is excreted from the body through the renal (aka urinary) and biliary systems.

Now, we mentioned cytochrome P450 enzymes and the vital role they play in metabolising CBD. But, what are they exactly?

CBD Medication mobile-update-EN

What Is the Cytochrome P450 System?

CBD's interactions with other drugs largely stem from their common metabolizing process and effects produced in the cytochrome P450 system. This group of liver enzymes (isoenzymes) is mainly responsible of modifying toxins, drugs, and other substances in our system. These enzymes basically alter these substances to make them easier to eliminate from the body.

But, when CBD enters the body, the liver may reduce the metabolising rate of other drugs that also rely on cytochrome P450 enzymes.

Albeit temporarily, in some cases, CBD can almost completely block the cytochrome P450 activity, affecting the metabolic activity of compounds found in certain drugs. So, for example, if you’re taking a powerhouse painkiller like oxycodone alongside cannabidiol (CBD), the former may linger in your system for longer and in higher concentrations than expected— which isn’t necessarily a good thing.

What can be problematic is that a drug like oxycodone is only supposed to stay in your system in determinate amounts for a certain period of time. Going beyond that duration may elicit overdoses or increase of side effects like nausea and drowsiness. All this could be an issue if you’re driving a car or operating heavy machinery. At worst, these interactions can also cause other damages to your body.

Drugs CBD Oil Can Interact With

The fact of the matter is, cytochrome P450 enzymes metabolise around 90%[1] of all medications on the market, with two izoenzymes in particular—CYP3A4 and CYP2D6—being responsible for the lion’s share of the work. So, here’s a simplified answer: almost any drug metabolised by cytochrome P450 enzymes will interact with CBD oil. Some of these drug interactions will bear no notable adverse effects, while others will.

Let’s get a little more specific. A 2016 study[2] delved into how CBD reacted with a known anti-seizure medication called clobazam, which is largely used to treat epilepsy among children. This interaction is particularly intriguing, as CBD (in synthetic form, "Epidiolex") has also been approved for treatment-resistant forms of Lennox–Gastaut syndrome and Dravet syndrome.

The study found that cannabidiol slowed down the metabolism of clobazam, which led to a significant increase in plasma levels of medication in the body—around 60–80%. As a result, researchers were able to lower the dose of clobazam administered to the subjects, without sacrificing efficacy. Even more interesting, the drug’s side effects, like insomnia, loss of coordination, drowsiness, and constipation, were all curbed with this lower dose.

  • Basics of Pharmacodynamics and CBD-Drug Interaction: Examples

A substrate is any substance modified by an enzyme. In respect to drugs, there are two kinds of substrates: ones that are already active when they are ingested, which are simply called drugs (for example, THC, the main compound of cannabis), and ones that must first be metabolised in order to become active, which are called prodrugs (for example, psilocybin, which is the prodrug of psilocin, the main active component of “magic mushrooms”).

These substrates usually do not affect the normal activity of the enzyme that metabolises them. However, there exist other substances that can increase the metabolic activity of cytochrome P450 enzymes: enzymatic inducers. There are also others that can reduce or even block normal enzymatic activity, known as enzymatic inhibitors. All of them can interact with one another, too.

Kind of substrate Drug Pro-drug
Effect when combined with an enzymatic inhibitor (including CBD) Increase Reduction
Effect when combined with an enzymatic inducer Reduction Increase
Effect when combined with an enzymatic inducer + CBD Variable Variable

Also included are some considerations on whether or not cannabidiol should be used.

Drugs CBD Oil Can Interact With

  • CYP3A4 Substrates

CYP3A4, specifically, is an liver and intestines isoenzyme forming part of the cytochrome P450 that oxidises toxins or drugs for easier excretion from the body.

Some Iimmunosuppressants and antidepressants alongside antipsychotics, calcium channel blockers, and opioids are substrates of this isoenzyme. Also part of these substrates are benzodiazepines, z-hypnotics, statins, and chemotherapeutics.

The risk of side effects, loss of effect or on the contrary, overdose may be increased when in co-administration with CBD – an enzymatic inhibitor. The safest situation is to not combine these drugs until receiving an expert recommendation.

Some medications metabolised by the CYP3A4 enzyme
Amlodipine Sinvastatin
Haloperidol Citalopram
Fentanyl Cabazitaxel
Zolpidem Tacrolimus
  • CYP34 Inhibitors

Protease inhibitors are antiviral drugs that are usually prescribed to patients diagnosed with HIV. Valproic acid, on the other hand, is a medication used for epilepsy treatment.

These drugs are examples of CYP3A4 inhibitors, and they are quite similar to their substrate counterparts.

When CBD interacts with any of these drugs, its bioavailability—or the bloodstream drug concentration —tends to increase. As a result, the risk of adverse effects may rise.

Experts don’t advice taking CBD alongside these medications, but a reduced dose is recommended, should you decide to combine both medications.

Protease inhibitors and valproic acid are examples of stronger CYP34 inhibitors. Other ones are amiodarone, verapamil, aprepitant, and cimetidine.

Some medications that inhibit CYP3A4 activity
Allopurinol Fluconazole
Amiodarone Fluoxetine
Amprenavir Quinolones
Aprepitant Valproic acid
Atazanavir Erythromycin juice
Chloramphenicol Imatinib
Cimetidine Indinavir
Clarithromycin Isoniazid
Nifedipedine Itraconazole
Tamoxifen Ketoconazole
Cyclosporine Nefazodone
Darunavir Nelfinavir
Dasatinib Ritonavir
Delavirdine Verapamil
Diltiazem Saquinavir
  • CYP3A4 Inducers

Barbiturates are medications used to treat people suffering from seizures.

In this case, increasing the dose of cannabidiol might seem logical; however, this idea should not be pursued due to the intrinsic risks of overdose and side effects when combining CBD with some medications.

Other examples of CYP3A4 inducers are detailed in the following table.

Some medications and herbs which induce the CYP3A4 activity
Carbamazepine Omeprazole
Corticosteroids Rifampin
Efavirenz Oxacarbazepine
Rifabutin Phenytoin
Modafinil Primidone
Nevirapine St. John's wort
  • CYP2C19 Substrates

The CYP2C19 isoenzyme metabolises xenobiotics like anti-seizure medications. And, like CYP34 substrates, they could carry some side effects when mixed with CBD.

Similarly, co-administration with cannabidiol isn’t advised, and adverse effects and toxicity need to be monitored closely.

Other examples of CYP2C19 substrates are proton pump inhibitors, antidepressants, antiplatelet drugs, muscle relaxants, and blood thinners.

Some medications metabolized by the CYP2C19 isoenzyme
Aripiprazole (Abilify) Lansoprazole (Prevacid)
Carisoprodol (Soma) Mephenytoin (Mesantoin)
Citalopram (Celexa) Methadone
Clomipramine (Anafranil) Propranolol
Clopidogrel (Plavix) Voriconazole (Vfend)
Clozapine (Clozaril) R-warfarin
Desipramine (Norpramin) Moclobemide (Manerix)
Diazepam (Valium) Nelfinavir (Viracept)
Sertraline (Zoloft) Olanzapine (Zyprexa)
Thalidomide Omeprazole (Prilosec)
Proguanil Pantoprazole (Protonix)
Diphenhydramine (Benadryl) Pentamidine
Doxepin (Sinequan) Phenobarbital
Escitakopram (Lexapro) Phenytoin
Fluoxertine (Prozac) Rabeprazole
Imipramine (Tofranil)
  • CYP2C19 Inhibitors

Those who use anxiolytics may be familiar with fluoxetine. It is also used to treat specific mental conditions like depression and even bulimia. Similarly, fluvoxamine is an antidepressant that is mainly used by people with obsessive-compulsive disorder.

These two drugs are primary examples of CYP2C19 inhibitors. As it is with these medications, CBD’s bioavailability could potentially increase. The risk of adverse effects may rise as a result, which is why lower CBD doses are advised, though drug combination avoidance is a better option.

Some medications that inhibit CYP2C19 activity
Chloramphenicol Isoniazid
Cimetidine (Tagamet) Moclobemide (Manerix)
Clopidogrel (Plavix) Modafinil (Provigil)
Delavirdine (Rescriptor) Omeprazole (Priosec)
Efavirenz (Sustiva) Oxcarbazepine (Trileptal)
Esomeprazole (Nexium) Ticlopidine (Ticlid)
Felbamate (Felbatol) Voriconazole (Vfend)
Fluconazole (Prozac) Fluconazole (Diflucan)
Fluvoxamine
  • CYP2C19 Inducers

Tuberculosis patients will be greatly familiar with rifampicine. It’s a oral medication used as an antibiotic to treat bacterial infections. Meanwhile, carbamazepine is an anticonvulsant used to treat seizures and neurological pain.

These two drugs are the best examples of CYP2C19 inducers. Theoretically, they could be safer when taken with CBD because, unlike inhibitors, the bioavailability of the cannabinoid decreases upon interaction, resulting in a reduction in effectiveness. In any case, it is not recommend to increase CBD dose if administered with CYP2C19 inducers.

Some medications and herbs that induce CYP2C19 activity
Aminoglutethimide Primidone
Artemisinin Rifampin
Barbiturates Rifapentine
Carbamazepine St. John's wort
Phenytoin
  • CYP2C8/9 Substrates

Both CYP2C8 and CYP2C9 enzymes are responsible for metabolising xenobiotics. However, the former can also metabolise polyunsaturated fatty acids.

Therefore, there is an increased risk of side effects when combined with CYP2C8/9 inhibitors. Co-administration with CBD isn’t advised, and using lower substrate doses to obtain the same CBD effect is not recommended.

A good example of a CYP2C8 and CYP2C9 substrate is rosiglitazone, a medication for type 2 diabetes. Antihypertensive drug losartan is also part of this list, along with naproxen, celecoxib, rosuvastatin, and sulfonylureas—just to name a few.

Some other medications metabolized by the CYP2C8/9 isoenzyme
Amiodarone (Cordarone) Carbamazepine (Tegretol)
Diclofenac (Voltaren) Paclitaxel (Taxol)
Repaglinide (Prandin) Cabazitaxel (Jevtana)
Chloroquine (Aralen) Ibuprofen (Advil)
Rosiglitazone (Avandia) Treprostinil (Tyvaso)

What Is the Grapefruit Test?

You’ve probably seen the “grapefruit warning” on some of your medications. If you’re taking one of these drugs, you’re advised to avoid consuming any grapefruit and other types of citrus. But why is that?

Like CBD, grapefruit and other citrus inhibits cytochrome P450 enzymes, which directly affects the metabolism of these substances. That means consuming grapefruit could modify the dose of the drug or the prodrug in the bloodstream, which may result in an overdose or reduction in drug efficiency.

Research shows that more than 85 drugs[3] share this same interaction with grapefruit. Among them are fentanyl, erythromycin, losartan, loratadine, and alprazolam.

If in Doubt, Speak to Your Doctor

So, with all the hype behind it, is it safe to take CBD oil while on medication? If you’ve read through the entire article, the most logical answer would be: it depends on what you are taking, the method of administration, and the dose.

Nothing good ever came from uninformed dosing or practising excessive use.

But, if you want to be on the safest side, ask your doctor. They can speak to you in lay terms about the effects of these drugs and how CBD may interact with them. This is the best way to obtain sound advice and answers to any questions you may have.

Medical DisclaimerInformation listed, referenced or linked to on this website is for general educational purposes only and does not provide professional medical or legal advice.

Royal Queen Seeds does not condone, advocate or promote licit or illicit drug use. Royal Queen Seeds Cannot be held responsible for material from references on our pages or on pages to which we provide links, which condone, advocate or promote licit or illicit drug use or illegal activities. Please consult your Doctor/Health care Practitioner before using any products/methods listed, referenced or linked to on this website.

External Resources:
  1. The Effect of Cytochrome P450 Metabolism on Drug Response, Interactions, and Adverse Effects - American Family Physician https://www.aafp.org
  2. Human Metabolites of Cannabidiol: A Review on Their Formation, Biological Activity, and Relevance in Therapy https://www.ncbi.nlm.nih.gov
  3. Common Grapefruit Juice Drug Interactions - Drugs.com https://www.drugs.com
Disclaimer:
This content is for educational purposes only. The information provided is derived from research gathered from external sources.

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Privacy Policy - Royal Queen Seeds

To ensure a safe online environment and guarantee adequate data protection, we strictly comply with all legal requirements. In this privacy statement, we provide information about how and for what purpose data is collected, safety measures, storage periods and contact details.


COMPANY NAME: SNORKEL SPAIN, SL (hereinafter ROYAL QUEEN SEEDS)

C/ Vilar d'Abdelà, 5 (nave 1) CP: 08170 de Montornès del Vallès

+34 937 379 846

support@royalqueenseeds.com


The present Privacy Policy sets out the terms on which we will treat personal data at ROYAL QUEEN SEEDS; this includes any personal data collected through our website https://www.royalqueenseeds.com/ as well as any other data we process in the course of our business activities.

ROYAL QUEEN SEEDS collects the following personal data for the purposes listed below:

SECTION 1 – PERSONAL INFORMATION WE COLLECT

1.1 Account purchases

Account purchases can only be made if you are in possession of a personal account. When you create an account or purchase something from our shop, as part of the buying and selling process we collect the following personal information that you provide to us:

This information is required for delivery. In addition, when you browse our shop, we automatically receive the Internet Protocol (IP) address of your computer. Based on this information, we can optimise your online experience and at the same time protect our online environment.

Purpose of data collection

We collect and store account-related data for the following purposes:

(a) to carry out obligations arising from any contracts between you and us, and to provide you with information, products and services that you may request from us;

(b) to set up, manage and communicate with you about your account and your orders;

(c) to conduct market research and analysis;

(d) to confirm your age and identity, and to detect and prevent fraud.

1.2 Newsletters

With your explicit permission, we may send you newsletters about our shop, new products and other updates. We send newsletters based on your explicit consent. In the event that you purchase a product, and in accordance with current regulations, we may send you commercial communications in accordance with the legitimate interest of our company, always about products or services similar to those you have purchased or contracted. In any case, you may exercise your right of opposition through the channels announced in this Privacy Policy. The following information is collected in relation to the newsletter:

We do not need to know the sex of the person in order to send the newsletter (data minimisation: by law we must ask for data that is strictly necessary to provide the service, and in this case knowing the sex is not necessary to send the newsletter).

Purpose of data collection

The data collected is used to:

(a) personalise our emails, including your name and gender;

(b) provide gender-specific content.

You can withdraw your consent at any time by using the link provided in the newsletter or the contact information provided in section 2.

1.3 Customer service and contact form

In order to provide appropriate support, our customer service employees have access to information related to the account. Consequently, their support will be highly effective and friendly. The data provided in our contact form is used by our CRM provider, SuperOffice. We will only use your details to respond to your message.

SECTION 2 – LEGITIMATE INTEREST

If you have purchased any of our products, please note that we may process your personal data for promotional purposes, based on Royal Queen Seeds' legitimate interest only to offer you products or services from our company and about products or services similar to those you have purchased. You may exercise your right to opt out of future messages by the means set out in this Privacy Policy or through any notification you receive.

2.1 How do you withdraw consent?

If you change your mind, you can withdraw your consent for us to contact you for the purpose of collecting, using, or disclosing your data at any time by reaching out to us at: support@royalqueenseeds.com.

SECTION 3 – DISCLOSURE

We may disclose your personal information if we are required to do so by law or if you breach our Terms of Service.

SECTION 4 – HOW LONG DO WE KEEP YOUR DATA?

At Royal Queen Seeds, we will not retain your data for longer than is necessary for the purposes described in this Policy. Different retention periods apply for different types of data; however, the longest period we will normally hold any personal data is 10 years.

4.1 Account information

Data relating to the account remains relevant for as long as the consumer is in possession of an account. Therefore, the data remains documented for as long as the account exists. When our customers delete an account, the associated data will be deleted within a reasonable period of time. Requests regarding the inspection or correction of stored personal data or the deletion of an account can be sent to support@royalqueenseeds.com.

4.2 Newsletters

In the event that you give us your consent to inform you about our products or services, we will keep your data until you express your wish not to receive any further communications from us. However, we regularly (every month) carry out a relevance check. Registered customers (and their personal information) will be deleted whenever customers do not reply to our request. In addition, our newsletter mailing has an opt-out feature. Consumers can withdraw their consent by using this opt-out feature.

SECTION 5 – COOKIES

Cookies are small information files that notify your computer of previous interactions with our website. These cookies are stored on your hard drive, not on our website. Essentially, when you use our website, your computer displays its cookies to us, informing our site that you have visited before. This allows our website to function more quickly and remember aspects related to your previous visits (such as your username), making your experience more convenient. At Royal Queen Seeds, we use two types of cookies: functional and analytical.

5.1 Functional Cookies

Functional cookies are used to enhance your online experience. Among other things, these cookies track what is added to your shopping cart. The use of these cookies does not require prior authorization.

5.2 Analytical Cookies

Analytical cookies are used for research and market analysis. The data collected with these analytical cookies is anonymous, making it unusable for third parties. The use of these cookies does not require prior authorization.

SECTION 5 – THIRD-PARTY SERVICES

Third-party services are required to conduct transactions and provide our services. In general, the third-party providers we use will only collect, use and disclose your information to the extent necessary to enable them to perform the services they provide to us.

However, certain third-party service providers, such as payment gateways and other payment transaction processors, have their own privacy policies regarding the information we must provide to them for your transactions.

We encourage you to read the privacy policies of these providers so that you can understand how these providers will handle your personal information.

In particular, certain suppliers may be located or have facilities located in a different jurisdiction than yours or ours. Therefore, if you choose to proceed with a transaction involving the services of a third party, your information may be subject to the laws of the jurisdiction in which that service provider or its facilities are located.

Once you leave our website or are redirected to a third-party website or application, you are no longer governed by this Privacy Policy or the Terms of Service of our website.

Web analytics service (anonymous data)

On this website we have integrated an element of a web analytics service (with anonymisation functionality). Web analytics can be defined as the gathering, processing and analysis of data about the behaviour of visitors to websites. An analytics service collects, among other things, data about which website a person came from (the so-called referrer), which sub-pages they visited or how often and for how long they visited a sub-page. Web analytics is mainly used for website optimisation and for a cost–benefit analysis of internet advertising.

Courier service

To complete deliveries we use a courier service. This courier service carries out the delivery between our company and the consumer's home. To complete these logistics, the company requires access to the consumer's name and address information.

Mailing service

Royal Queen Seeds uses a third-party mail service provider to send its newsletter. This provider has access to limited account information related to opt-in consent (e.g. email address).

Marketing services

Royal Queen Seeds has the support of a company that specialises in marketing and communication activities. Their access to personal information is very limited and mostly anonymous.

Payment services

At Royal Queen Seeds we use external payment services to handle our transactions (e.g. credit card payments).

SECTION 6 – SECURITY

To protect your personal information, we take reasonable precautions and follow industry standard best practices to ensure that it is not inappropriately lost, misused, accessed, disclosed, altered or destroyed.

If you provide us with your credit card information, the information is encrypted using secure socket layer technology (SSL) and stored using AES-256 encryption. Although no method of transmission over the internet or electronic storage is 100% secure, we follow all PCI-DSS requirements and implement additional industry standards that are commonly accepted. Information related to the account is protected with a hashing method. This method transforms the information into a generated hash. As a result, confidential information is protected and invisible, even to us. In addition, our databases are exceptionally protected against unauthorised access. For example, access to the database is only possible and permitted via approved IP addresses (e.g. from Royal Queen Seeds headquarters). Other attempts and addresses are rejected at all times.

Furthermore, data is anonymised as much as possible, so it cannot be directly linked to a specific consumer. With this data, however, we may be able to carry out market research and analysis. In addition, the third parties concerned (e.g. mailing service) are examined prior to our collaboration, comply with the GDPR from the EU and receive a processing agreement. Within Royal Queen Seeds, employees are assigned different access permissions. Specific permission provides access only to information that is strictly required to perform a task. Digital security measures are subject to change and must meet high requirements to ensure the safety of online customers. That is why, at Royal Queen Seeds, we appoint a security officer. Regular verification and improvement of security measures (where necessary) are part of the role.

SECTION 7 – CHANGES TO THIS PRIVACY POLICY

We reserve the right to modify this Privacy Policy at any time, so please check back regularly. Changes and clarifications will be effective immediately upon being published on the Website. If we make substantial changes to this policy, we will notify you here that it has been updated so you will know what information we collect, how we use it and under what circumstances, if any, we use and/or disclose it.

SECTION 8 – YOU HAVE THE RIGHT TO: