If you’re taking a prescription drug, you’ll want to check the CBD drug interactions list. While CBD is known for its low side-effect profile, it does interact with certain prescription drugs. The Cytochrome P450 enzyme family is responsible for the breakdown of approximately 60 percent of clinically prescribed medications. Thankfully, this is a relatively short list. Keep reading to learn about these and other possible interactions.


CBD and CYP2D6 can interfere with the metabolism of many drugs. The interaction between cannabis extracts and the CYP2D6 enzyme can have important implications for patients. Approximately 25 percent of approved drugs undergo CYP2D6 metabolization, including phenytoin, warfarin, and amitriptyline. For these reasons, drug interaction with CYP2D6 can lead to therapeutic drug monitoring or dose alterations.

To further understand the pharmacological implications of these findings, we compared the binding properties of pCBs with CYP2D6 mutants. Mutations of the CYP2D6 enzyme (WT) result in a lower binding affinity and greater distance from the heme. The results of these experiments indicated that pCBs have a greater affinity for pCB molecules and a lower binding affinity for CYP2D6*10.

We found that pCBs are not able to bind with residues near the heme iron, resulting in a smaller access channel. Because pCBs are flexible, they also have a lower binding affinity. This suggests that a large part of the drug interaction is caused by a low affinity of THC. As previously reported, CBD is also a good candidate for CBD drug interactions.

These findings suggest that CBD inhibits AEA metabolism by 2D6 at a subtherapeutic level, making it necessary to monitor patients who are taking CBD and interacting chemotherapeutic drugs. The authors note that further pharmacokinetic studies are needed to better understand how these drug interactions work and whether CBD can enhance or hinder cancer treatment. These results also suggest that patients taking a high dose of a cancer drug should be closely monitored for any drug interactions with CBD.

In vitro studies suggest that theophylline, a commonly prescribed bronchodilator, can interact with CBD. Although marijuana may reduce the effect of theophylline, it increases the rate of metabolic clearance of theophylline. This may have similar effects as tobacco smoking. Nevertheless, further studies are needed to determine whether cannabis and opioids are likely to interact.


Researchers have shown that CBD can interfere with the metabolism of many chemotherapy agents. Specifically, CBD inhibits the UGT1A9 enzyme, which is responsible for the breakdown of diflunisal and propofol. The effect of CBD on these medications will depend on the dosage and other factors. Nevertheless, this interaction between CBD and chemotherapy drugs is considered rare. In some cases, it can be fatal.

In other cases, the cannabinoids inhibit or induce the metabolism of other drugs. The cannabinoid Epidiolex/Epidyolex oral solution contains 100 mg/mL of CBD. The study involved healthy volunteers as well as patients with epilepsy. While CBD did not alter the activity of CYP3A4, induction or inhibition of the CYP3A4 enzyme resulted in a small reduction in the amount of CBD exposure.

Although this association is not completely known, the FDA has published a comprehensive list of drug-drug interactions with cannabinoids. The online supplementary material contains a comprehensive list of potential drug-drug interactions and detailed descriptions of each enzyme involved. For further information, visit DrugBank. There is no guarantee that CBD and CYP3A4 will interact. However, it is worth mentioning that the FDA’s decision to de-regulate cannabis is of greater significance than ever. The study may also help to establish which medications are compatible with CBD oil.

The CYP3A4 and CBD drug interactions review by Lester Bornheim in 1992 noted that CBD inhibits CYP3A4 enzymes at lower concentrations than required for an antiepileptic effect. Therefore, it may alter the processing of antiepileptic drugs and result in ineffective anti-epileptic relief. However, some physicians recommend increasing the CBD dose and adding THC to the mix.

There are several potential drug-drug interactions between CBD and other cannabinoids. In some cases, the drug may cause dizziness or confusion, or it may reduce or increase blood pressure. It may also increase the risk of cardiovascular events, such as tachycardia, hypotension, and syncope. As with any drug, careful monitoring of patients’ liver function is necessary to ensure that they are taking CBD in the correct dosage.


CBD and 9-THC, both cannabinoids derived from the cannabis plant, are becoming more available. Coadministering these drugs can have serious consequences for the patients, as cannabinoids may alter drug-drug interactions. These cannabinoids are used in the treatment of acute symptoms and routine medical conditions, as well as for recreational purposes. Several recent reviews have raised concerns about potential drug-drug interactions between CBD and other drugs.

CBD inhibits CYP2C19 in human liver microsomes. Because CBD and THC have similar structures, their inhibitory effects are expected to be similar. However, CBD inhibits CYP2C19 in a mixed-type fashion. CBD is also a potent inhibitor of CYP2C19. It has been found that CBD inhibits the activity of CYP2C19, which is a key enzyme for a variety of metabolic processes.

The clinical consequences of CBD and NSAIDs are unknown. While CBD inhibits the activity of CYP2C8 and CYP2C9, its effects on these enzymes have not been fully studied in vivo. Consequently, clinical data are needed to better understand the DDIs between CBD and NSAIDs. Still, physicians should be aware of the potential for CBD and NSAID interactions.

Despite the fact that CBD is a benign substance, its potential to interact with other medications is still a concern. In addition to potential drug interactions, it is also important to remember that it interacts with several common biological targets. Therefore, it is imperative that physicians and patients take note of these DDIs when prescribing CBD. These interactions may require cautionary dose adjustments for both CBD and other medications.

Although not well studied, it is important to remember that cannabis and CYP2C9 enzymes are likely to interact. CYP2C9 enzymes may inhibit the synthesis of diflunisal, propofol, and fenofibrate. Understanding the CYP2C9 enzyme’s role in marijuana metabolism may ultimately lead to clinically significant drug interactions.


The CYP2C19 enzyme is a central player in metabolism of several commonly prescribed drugs. Its substrates include citalopram, carisoprodol, and clobazam. CBD and THC inhibit both CYP2C19 and CYP1A2 but are not equally inhibiting. These interactions may require careful monitoring and reduced doses.

However, drug-drug interaction studies are rare, especially in complex medical populations. Drug-drug interaction lists containing cannabinoids are intended to be readily accessible resources. They include prescription, OTC, and illicit cannabinoid products. The full list of drug-drug interactions is available online as supplementary material. In Table 2, 57 prescription medications are listed with a corresponding NTI.

Other drugs that may interact with CBD include citalopram, fenofibrate, gemfibrozil, lamotrigine, and morphine. Inhibitors of CYP2C19 are known to affect CBD metabolism. While these interactions may be rare, CBD can increase the risk of adverse events and reduce the dose of prescribed drugs. This is because CBD inhibits the activity of these enzymes.

Although there are few data on the pharmacokinetics of cannabinoids, these drugs have a number of potential effects on the cardiovascular system, including sedation, confusion, and hypertension. In addition, cannabinoids are a potential therapeutic target for neurodegenerative diseases. Cannabinoids are implemented in many physiological processes, including appetite stimulation, energy balance, and pain modulation. This is why cannabinoids interact with prescription drugs, OTC medications, and illicit products.

CBD does not induce CYP2C19 activity. Therefore, it is important to consider a lower dose when CBD is coadministered with CLB. However, patients on concomitant STP should be closely monitored and dose adjustments may be necessary. These are only a few of the drug interactions involving CYP2C19 enzymes. You should consider the risks and benefits of each drug in your patient’s medical history when making a decision regarding the CBD dosage and timing.

CYP2C19 is the main enzyme responsible for the metabolism of CBD and THC. These two enzymes have very different roles in the body. CBD inhibits the CYP enzyme and CYP1A2, while THC stimulates CYP2D6. Both drugs interact with other cannabinoids, including phenytoin and tetrahydrocannabinoids.