Can You Mix CBD With Prescriptions Drugs?

We’ve all heard how alcohol can counteract the effects of certain pharmaceuticals or even have serious side effects when mixed. While alcohol is a recreational substance, many people use CBD for medical reasons, making this an even more important issue.

With the use of cannabis for medicinal purposes being legalized in various states throughout the United States, many patients are now taking advantage of the phenomenal medical benefits of CBD. However, this raises the question of the effects that CBD might have when used in conjunction with other medications.

While CBD is safe to use, there is the possibility that it interferes with other drugs that you are taking. In this article, we will take a closer look at how CBD interacts with 10 of the top medications that are used for different conditions.

What exactly is CBD, anyway?


Basically, CBD (short for cannabidiol) is a natural chemical component of the cannabis plant. It is classified as a “phytocannabinoid,” and is in fact just one of over a hundred different varieties that have been identified in marijuana.

By and large, CBD and THC (another phytocannabinoid) appear to be the two main “culprits” when it comes to the medicinal effects of marijuana. The reason CBD has hit the global limelight in such blistering fashion recently is the fact that, unlike THC, it does not produce any sort of high. Simply put, it appears to offer all of the therapeutic potential of cannabis with none of the psychoactive effects.

As with any compound that interacts with chemical pathways in the human body, though, it will behave differently and produce different effects depending on what other types of compounds are present within that same pathway. In other words, the effects of CBD will vary depending on what other medications you are taking. And regardless of what some companies and “cannabis doctors” out there may say, it most certainly does interact with other medications. Here are the ones that you need to look out for.

The way that CBD is metabolized by your body can interfere with how your body normally metabolizes other drugs you take. If those other drugs aren’t metabolized properly, they can hang around and stay in your system longer than you want. This can cause negative side effects and complications.

CBD drug interactions aren’t always bad. They can actually be a good thing. CBD can make other drugs more effective, so much so that you can reduce the dosage of those other drugs and thus have less negative side effects to deal with.

One kind of drug you should pay special attention to is a blood thinner like warfarin. Taking CBD with warfarin can make the warfarin stay in your system for too long without being broken down.

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The basic mechanism of the CBD-drugs interaction is their effect on cytochrome P450. This sofisticated moniker relates to a family of liver enzymes which plays the crucial role in metabolizing drugs. This key enzyme group metabolizes most of the drugs we consume, including more than 60 percent of marketed meds. It is therefore extremely versatile compound, especially considering that the majority of liver enzymes metabolize only one substance – or a group of substances.

When we intake CBD, the liver stops metabolising other drugs which use the same enzyme. If you’re taking a powerful painkiller like oxycodone, using CBD at the same time may cause it to stay in your system for longer than it should. These drugs were very carefully dosed to stay in your system for a specific period of time. Anything more than that, and you risk suffering from side effects like drowsiness and nausea. With regular use, liver damage can be a very serious consequence of this slow metabolic process.

In short, cannabidiol acts as a competitive inhibitor of cytochrome P450.Great, but what does it mean? This means that while being itself metabolised by P450 CBD largely “draws all his attention” – thus halting its action on other substances it would normally metabolise (another potent inhibitor of P450 is bergapten, commonly found in grapefruit). Of course, it is not that easy – the course and effects of inhibition of the process will depend on the dose and form of CBD intake… and also on whether we use isolate or the whole plant extract (which is the advisable way in most cases, due to the hauled entourage effect). Especially the last factor should be considered, bearing in mind that the majority of pre-clinical trials and clinical trials have been carried out on pure CBD or on drugs based on its isolate (eg. Sativex).

Which medications can you take?


Any drug that is metabolised by the liver will be affected by CBD. These will be processed differently with the presence of this cannabinoid in the system. This means that anything from steroids to antibiotics or antidepressants will be affected. But the list goes on. Be sure you ask your doctor about this. Your dosage will most likely have to be reduced once you start medicating with CBD.

Even though a lot of medical professionals aren’t up-to-date when it comes to CBD and other cannabinoids, they’ll still be the most viable option when it comes to talking about your health. Even not knowing anything about CBD, they can still monitor your blood work to make sure you’re healthy. Being 100% honest with your doctor will only do you good. There is no reason to feel scared or ashamed of your belief in the healing powers of cannabis.

As far as you’re concerned, the use of CBD may actually help with your current medication. It won’t make its effects stronger; but by delaying the metabolic process, it can actually help you decrease your current dosage.

In 2015, a study analysed how CBD reacted with clobazam a famous anti-seizure drug on a group of epileptic children. CBD made for a slower metabolisation of this drug. Because of that, the patients were able to decrease the dosage of clobazam. This is a pharmaceutical with side effects like drowsiness, mild fever, loss of coordination, insomnia, and vomiting and constipation, just to name a few.

With such a long list of possible side effects, it’s extremely good news that one can reduce the quantity consumed with the help of CBD. This decrease in the amount of clobazam consumed is directly correlated with the diminished chance of experiencing side effects from the drug.

What medications does CBD interact with?


In fact, basically any drug that is metabolized by cytochrome P-450 enzymes has the potential to interact with CBD. Let’s take a closer look at some of these drugs.

Prozac: Antidepressant

As most of us know, Prozac is a very well-known medication that’s used primarily to treat depression and panic attacks. It’s used to improve sleep, mood, energy levels, appetite, and may also help to restore interest in day-to-day living.

Cannabidiol (CBD) can be used to make people feel more relaxed, happier, and less stressed. As a result, people who suffer from anxiety or depression are more likely to use CBD (and more of it), when compared to people who don’t suffer from this condition. Of course, there are many people who suffer from these conditions who also take prescription anti-depressants. This is why it’s important that medical professionals and patients are aware of the potential interaction that could arise from combining the two.

One of the major challenges that physicians face when it comes to prescribing antidepressants to patients who use CBD, is determining the correct dosage to prescribe. This combination leads to difficulties in measuring the degree each substance produces side effects, and how they affect behavior and mood.

Adverse interactions between CBD and selective serotonin reuptake inhibitors (SSRIs) are rare. However, there are speculations based on isolated reports that combining SSRIs (such as Prozac) with CBD could increase the risk of hypomania, which is a mild form of mania.

Warfarin: Blood thinner

While the majority of patients who use blood thinners along with CBD suffer from no ill side effects, there is the possibility that it could cause problems. Common blood thinners like Warfarin are subjected to prolonged activity and increased effect when taken together with CBD, and this could result in elevated INR, which is a test used to monitor the effects of warfarin). A 2007 study published in “Phytomedicine,” for example, showed that CBD has some mild anti-coagulating effects. This means that CBD can increase warfarin levels, which means that people on warfarin should exercise caution when adding CBD to the mix. Essentially, adding CBD to the mix can cause blood to thin temporarily. This could have the same dangerous effects as taking a double dose of warfarin, as it increases the risks but shouldn’t cause any long-term issues. As CBD is excreted from the body, the clotting factors and platelets should return to their previous levels.

Risperidone: Antipsychotic

Risperidone is an antipsychotic medication that is commonly prescribed to treat mild cases of schizophrenia, bipolar disorder, and ASD. While there is no reason to worry that the combination of risperidone and CBD will lead to life-threatening side effects, some users have reported severe anxiety attacks due to the combination. Also, high doses of CBD could potentially lead to its prolonged activation. This is also the case for drugs like haloperidol, which is a similar antipsychotic medication of the same class. Ultimately, CBD has the potential to intensify the side effects associated with risperidone. Moreover, antipsychotic medications are used as tranquilizers and are most effective in treating people who have hallucinations, psychotic episodes, and delusions associated with schizophrenia and other psychotic disorders. The way that CBD interacts with the enzyme cytochrome P450 is vital, as they can essentially deactivate each other.

Clobazam: Epilepsy and seizures

Although CBD has proven to be an effective and safe treatment option for epilepsy and seizures, a 2015 publication in “Epilepsia” has shown that frequent use of CBD could increase the levels of Clobazam in both adults and children. In this same study, adults who were taking clobazam reported sedation more frequently. Furthermore, a study conducted by Dr. Gaston and her team at the University of Alabama at Birmingham found that CBD could potentially alter the blood levels of commonly used antiepileptic drugs such as Clobazam. While it’s not fully understood why this happens, it is thought to be because CBD is a strong inhibitor of various enzymes in the human cytochrome P450 system. Another interesting finding from one of the studies done on how CBD interacts with other medications revealed that when Clobazam is broken down, it may interact with CBD in some people resulting in fatigue and tiredness. Again, findings aren’t conclusive, but there does seem to be the possibility of negative effects when these two substances are used in conjunction with one another.

Nyquil: Cold and Flu relief

The problem here is actually with a substance called doxylamine, which is an antihistamine that can be found in Nyquil and other over the counter allergy medicines. The combination of CBD and any of these types of medicines can lead to increased confusion, drowsiness, cognitive impairments, and decreased motor function. CBD is responsible for blocking the action of the enzymes in the liver that break down most of the medicines you find on pharmacy shelves, and since the liver is the primary detoxifying organ in the body, the action of blocking its enzymes can result in the possibility that over the counter drugs might not be effectively cleared from the system. This can significantly increase the chance of negative side effects.

HIV Antiretrovirals

All medications that enter the body are eventually metabolized, either to be activated so that they can work in the body or broken down for elimination from the body. The problem occurs when the same enzyme works on two different medications, as is the case with CBD and antiretrovirals. The outcome will depend on the interaction of the medicines with the enzyme.

To put it simply, if one medicine induces the enzyme to increase production, but the other is broken down by it, the effect of the second medicine would be reduced because its breakdown is sped up by the existence of the other medicine. If both medications inhibit the actions of the enzyme, the effect of both medications will be increased. However, if both medications induce the enzyme, the effects of both medications could be decreased. Moreover, when certain antivirals such as atazanavir, ritonavir, and saquinavir are taken with CBD, they could increase the duration and effects of the CBD, but may also lead to an increase in their own side effects. For this reason, patients who start using CBD after using these medications are cautioned to start with a low dosage.

Xanax: Anti anxiety

While mixing Xanax with CBD isn’t as dangerous as mixing it with certain other substances (like alcohol or opioids), you should still exercise caution. Mixing Xanax and CBD may heighten the side effects of either or both substances, meaning you could experience severe drowsiness, concentration problems, or even confusion. Also, keep in mind that the combination of CBD and Xanax could result in poor decision making. For example, you may be more likely to add alcohol to the mix, and consuming alcohol with Xanax can be very dangerous.

Buprenorphine: Pain Medication

Buprenorphine is an opioid pain medication that is thought to have a high potential for addiction. In high doses, this is a drug that could cause coma, respiratory distress, or even death. And when combined with CBD, the risk of these things is believed to increase as both substances are known to depress the central nervous system. Cannabis and buprenorphine are both sedatives, which means that there is a high chance of becoming hypersedated when you combine the two. A list of drugs that contain buprenorphine includes: Bunavail, Probuphine, Butrans, Suboxone, and Belbuca among others. Symptoms to look out for are slowed speech, slowed or irregular heartbeat, difficulty controlling motor functions, or excessive sedation.

Beta blockers: Blood pressure

Generally speaking, those with heart conditions need to be cautious when it comes to cannabis, as CBD can cause blood pressure and heart rate levels to fluctuate. In other words, it could make you more sensitive to a heart attack. This is especially true for individuals who have just started taking CBD and have not yet developed a tolerance. Even for regular consumers, CBD may slow down the heart rate. Well-known beta blockers include Tenormin, Toprol-XL, Sectral, Bystolic, and Zebeta.

Sodium oxybate: anti-sleep medication

Sodium oxybate is an anti-sleep medication often used to treat narcolepsy. When combined with CBD, there is the risk of depressing the central nervous system to dangerous levels. In very severe cases, this could contribute to a coma. Other symptoms to look out for are depression, dizziness, low blood pressure, shallow breathing, and impaired motor function.

Can you smoke weed while on medication?


We’ve discussed how CBD can affect the behaviour of other drugs. But it is very important to note that when you smoke a joint, you’re likely not ingesting anywhere near the medicinal dose of CBD.

Most cannabis strains out there contain less than 1% CBD. With 1% CBD in each gram of weed, you’ll be consuming 10mg of CBD for every gram of bud. This is a very small quantity. Especially when considering epilepsy patients took up to 300mg of CBD to abate symptoms. This is the same as smoking 30 grams of bud.

So, if you’re taking medication and use cannabis recreationally, just don’t abuse it. Pay close attention to what your body tells you. You shouldn’t feel any difference in the impact your medication has. But either way, ask your doctor for all the information he/she can give you. If you’re still worried, visit the doctor every month or so. This will help you be sure you’re fine and give you peace of mind.

All in all, much more research needs to be carried out regarding the use of CBD with other medications. Numerous studies have pointed out the potential therapeutic benefits of CBD, but until doctors and researchers fully understand the compound’s molecular activity and physiological pathways, extra precaution should be taken when administering it along with any other conventional or alternative medicines.

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