Mixing CBD with Other Medications
CBD has erupted in popularity over the past few years, acclaimed for its many potential health and wellness benefits.
Thought to help with relaxation, focus, mood, pain, and inflammation, there’s a whole host of reasons why you might be interested in adding CBD to your everyday routine.
However, CBD is a bioactive compound that has a range of interactions with different compounds – and medications – that are active in the body.
If you’re regularly taking medication, it’s only natural to think about the possible effects taking CBD might have. While CBD is considered to be very safe, it can produce some unwanted side effects when taken alongside certain drugs.
So, how can CBD interact with medications, and which combinations should be avoided?
Please Note – This is not an exhaustive list and should not be considered medical advice. Be sure to always consult with a medical professional before using CBD with any type of medication.
How Can CBD Interact with Medications?
When CBD is active in your system, it can interact with or influence the effects of certain medications. This happens in one of three different ways:
Duplication – When two compounds with similar effects are taken, they may overly impact the system, exaggerating the side effects.
Opposition – When two compounds work to produce opposing effects, they may cancel each other out, rendering medication ineffective.
Alteration – This is where one substance alters the way that another is metabolised or absorbed by the body, which can lead to active levels in your system being too low or high.
When CBD does affect medications, it is usually a result of alteration, blocking or affecting the compound from being metabolised at the correct rate.
Blood Thinners
Anticoagulants, known as blood thinners, are highly important drugs that help at-risk patients avoid blood clots, keeping blood flowing smoothly through their veins. They can reduce the risk of serious medical problems like heart attacks and stroke.
Many patients taking blood thinners may consider taking CBD as a way to relieve anxiety or pain – unfortunately, this is not always a good idea.
While CBD doesn’t have any direct effects on the blood, it does affect the metabolism of certain blood thinners by inhibiting CYP enzymes. This can slow the processing of the blood thinners, leading to active levels becoming dangerously high.
When your system has too many active blood thinners, your blood can struggle to clot entirely, even when it’s needed. This increases your risk of internal bleeding or haemorrhage.
Not all blood thinners are metabolised by the CYP450 enzymes of the liver, so you may be able to take them alongside CBD – just be sure to consult with your doctor first.
Example Drugs: Warfarin, heparin, apixaban, and dabigatran
Type of Interaction: Alteration
Possible Side Effects: Prolonged bleeding, internal bleeding, haemorrhage
Thyroid Medications
Your thyroid is an important gland in the body that produces the hormones that regulate metabolism. Unfortunately, many people have issues with their thyroids, which can cause them to be underactive or overactive.
Hyperthyroidism is when your thyroid produces more hormones than it should. Hypothyroidism is when it doesn’t produce enough.
CBD has been touted as a good solution for these issues – as CBD can interact with your cannabinoid system to help regulate the release of hormones – but some in the medical community warn against mixing it with thyroid medication.
It’s thought that CBD could negatively interact with thyroid medications due to the way they are metabolised. Both are metabolised in the liver via your cytochrome p450 pathways, which could result in the CBD slowing the rate at which levothyroxine is processed.
Slowing the metabolism of levothyroxine could result in levels getting too high, causing hyperthyroidism. If you have thyroid issues, be sure to speak to your doctor before trying CBD.
Example Drugs: Levothyroxine
Type of Interaction: Alteration
Possible Side Effects: Hyperthyroidism, fatigue, weight loss, anxiety, irritability, headache, tremors
Antidepressants
Many commonly prescribed antidepressants – namely selective serotonin reuptake inhibitors (SSRIs) – have an unfortunate relationship with CBD.
These SSRIs treat depression by increasing serotonin levels and slowing the rate at which they are metabolised. This keeps them active in your body longer, helping to improve mood.
While they might be effective, if antidepressants are not properly absorbed by your body, it can result in some nasty, unwanted side effects.
Studies have shown that CBD slows the rate at which common SSRI antidepressants are metabolised, leading to an increase in active levels. This can raise the chances of concentration-related side effects, like nausea or dry mouth.
Many patients have reported that CBD can help with their mood, but it’s important to check with your doctor first. They may advise you to take your CBD at a different time of day or that you try other treatments.
Drugs Not To Be Mixed: Sertraline, citalopram, escitalopram, fluoxetine, paroxetine
Type of Interaction: Alteration
Possible Side Effects: Nausea, headache, dry mouth, insomnia, nervousness, agitation, dizziness
Beta-Blockers
Beta-blockers slow down your heart rate and lower your blood pressure by blocking the action of hormones like adrenaline and noradrenaline.
Doctors prescribe them for a number of reasons. They’re commonly used to reduce the risk of heart attack and hypertension, but they’re also used to help with anxiety symptoms and migraines.
CBD is also known for its benefits for stress and anxiety, but mixing the two could be a bad idea. Beta-blockers are metabolised by the liver’s CYP450 enzyme system, just like CBD. When you take both, they can compete for this pathway, meaning the body takes longer to break them down, leading to overly high levels in the blood.
Having too many active beta-blockers in your system leads to an increased risk of adverse side effects, potentially causing your blood pressure to go too low.
CBD can be used with certain beta-blockers, but it’s important to speak to your doctor first. They can advise you on how and when to administer CBD and discuss any possible side effects.
Example Drugs: Propranolol, bisoprolol, atenolol, metoprolol
Type of Interaction: Alteration
Possible Side Effects: Tiredness, exhaustion, lethargy, lightheadedness, shock
Calcium Channel Blockers
Calcium channel blockers are another type of medication that is used to help lower blood pressure, stopping hypertension. Calcium makes your heart and arteries squeeze more, so blocking it can allow your vessels to open up and relax.
CBD can also help to relax your blood vessels. While there isn’t any direct interaction with calcium channel blockers, taking them both together could cause your blood pressure to drop too low, resulting in unwanted side effects.
You may be completely fine taking both, but be sure to get the go-ahead from your doctor before trying it out.
Example Drugs: bepridil, amplodipine, isradipine, nicdardipine, nisoldipine
Type of Interaction: Duplication
Possible Side Effects: Blurry vision, confusion, lightheadedness, dizziness, lethargy
Benzodiazepines
Benzodiazepines are a common type of sedative which work by slowing down the functions of the body and the brain. They can be prescribed to help deal with symptoms of anxiety or trouble with insomnia.
Many also use CBD to help with anxiety and sleep, with research showing that it exerts a calming effect on the body’s nervous system, helping users relax.
It’s no wonder, then, that many benzodiazepine users look towards CBD for some extra help with their symptoms; however, this can prove to be a little too effective. Both interact with your brain’s GABA receptors, so when taken together, the sedative effects can become too much.
It’s possible to take both CBD and benzodiazepines, but it’s important you speak to a medical professional to get advice about dosage and what time of day to take them.
Example Drugs: lorazepam, diazepam, clonazepam. alprazolam, midazolam
Type of Interaction: Duplication
Possible Side Effects: Poor coordination, excessive drowsiness, impaired cognitive function
Anti-seizure Medications
There’s a lot of interest in the potential for CBD to help those suffering from epilepsy, leading many to try it out in an effort to reduce their symptoms.
Some studies have been carried out to show that CBD can actually work synergistically with anti-seizure to improve their effects, with indications it can increase the efficacy of antiepileptic medications.
That being said, research is still in its early stages, and other studies have suggested that CBD could negatively impact the metabolisation of seizure medications, resulting in levels becoming too low or too high.
There is a wide range of anti-seizure medications available, so if you’re considering using CBD, be sure to check with your doctor to double-check the potential risks of any interactions.
Example Drugs: Valproic acid, sodium valproate, phenytoin
Type of Interaction: Alteration
Possible Side Effects: Increased risk of seizures, drowsiness, dizziness
Over-the-Counter Drugs That Should Not Be Mixed with CBD
Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)
Perhaps the most commonly used class of over-the-counter medications, NSAIDs (like ibuprofen), are often used to help deal with pain, headaches, and cold and flu symptoms.
These drugs work by helping to reduce inflammation, the most common source of physical pain. Many also use CBD to try and relieve aches and pains, but this can have unintended consequences.
Both NSAIDs and CBD are metabolised by the same enzymes in the liver, so when you take both at once, it can lead to levels being too high.
If you do take both, it’s always a good idea to take them at different times of the day to avoid excessive concentrations. Consult your doctor before ever taking the two together.
Example Drugs: Ibuprofen, aspirin
Type of Interaction: Alteration
Possible Side Effects: Indigestion, nausea, drowsiness, kidney damage
Antihistamines
Histamine is a hormone that attempts to protect the body by causing the skin to swell and blood vessels to expand. This can lead to irritation. Anti-allergy tablets block the effects of this hormone, soothing symptoms.
The same pathways in the liver metabolise CBD as antihistamines, so your body breaks them down slower, causing antihistamine levels to be higher.
Having more antihistamines in your system can lead to more side effects, so if you’re taking them regularly, it’s a good idea to talk to your doctor before trying CBD.
Example Drugs: Diphenhydramine, cetirizine, fexofenadine
Type of Interaction: Alteration
Possible Side Effects: Drowsiness, dry mouth, nausea, increased appetite
Do Different Forms of CBD Affect Medication Differently?
There’s no definitive answer to this question, but some in the medical community believe that the way you administer CBD is important when it comes to interactions with medications.
This is thanks to the rate of absorption. When you vape CBD, you absorb it directly into the bloodstream via your lungs, allowing you to reach higher concentrations within a shorter time.
It’s thought that this could increase potential complications with other medications, where they are both competing for metabolisation. This may raise the chances the active level of medications in your body is too high, leading to adverse side effects.
Other forms of CBD, such as CBD gummies, are absorbed by the body more gradually, meaning concentrations are lower. Because there’s less concentration, it’s believed that the chances of negative medication interactions should be reduced.
Finding a Safe CBD Product
If you’re looking to add CBD to your routine, it’s crucial that you purchase a high-quality product from a trusted manufacturer to avoid any hidden or potentially harmful ingredients.
Vapoholic is a fully certified member of the Cannabis Trades Association (CTA) UK, with all of our CBD products being produced in accordance to the rigorous Medicines and Healthcare Regulatory Agency (MHRA).
Each of our CBD e-liquids, gummies, oils, and powders, is made with pure CBD – with no THC (>0.2%). If you think you need some help getting to grips with which product is right for you, take a look at no-nonsense CBD guides:
If you’re struggling to decide which CBD product is right for you, take a look at our handy CBD quiz!
Remember, no matter which CBD product you choose, it’s always best to seek qualified medical advice before use. Stay safe, and enjoy!