From the Guidelines
Caution is advised when using CBD alongside acenocoumarol due to potential significant drug interactions that could increase bleeding risk. CBD can inhibit the CYP2C9 enzyme responsible for metabolizing acenocoumarol, potentially leading to increased anticoagulant effects and elevated INR levels, as suggested by the potential for drug-drug interactions mediated through altered drug metabolism pharmacokinetics 1. This interaction may require acenocoumarol dose adjustments to maintain therapeutic anticoagulation while avoiding dangerous bleeding complications. Some key points to consider include:
- Patients should inform their healthcare provider about CBD use before starting or continuing acenocoumarol therapy.
- If both substances must be used concurrently, more frequent INR monitoring is recommended, especially when starting, stopping, or changing CBD dosage.
- Signs of excessive anticoagulation that warrant immediate medical attention include unusual bruising, nosebleeds, bleeding gums, blood in urine or stool, and severe headaches.
- The severity of this interaction may vary based on CBD dosage, formulation, and individual factors like genetics, age, and liver function.
- Patients should never adjust their acenocoumarol dose without medical supervision, even if they experience interaction effects. It is essential to note that the pharmacokinetics of THC and CBD, including their bioavailability, vary according to formulation and route of administration, which could impact the severity of the interaction with acenocoumarol 1. Given the potential for significant drug interactions, it is crucial to prioritize caution and closely monitor patients using both CBD and acenocoumarol to minimize the risk of adverse effects.
From the Research
Potential Interactions between Cannabidiol (CBD) and Acenocoumarol (AVK)
The potential interactions between CBD and AVK are not directly addressed in the provided studies. However, the studies do discuss the potential interactions between CBD and other anticoagulants, such as warfarin.
- The study 2 found that there is limited evidence to support an interaction between cannabinoids and anticoagulants, except for warfarin.
- The study 3 found that cannabis may inhibit the metabolism of warfarin, resulting in increased plasma concentrations and risk of bleeding.
- The study 4 found that CBD may inhibit the activity of certain enzymes, such as CYP2C9 and CYP2C19, which are involved in the metabolism of warfarin and other anticoagulants.
Mechanisms of Interaction
The potential mechanisms of interaction between CBD and AVK are not well understood. However, it is possible that CBD may interact with AVK through similar mechanisms as warfarin, such as:
- Inhibition of CYP2C9 and CYP2C19, which are involved in the metabolism of AVK 4
- Inhibition of other enzymes, such as CYP1A1/2 and CYP3A4/5/7, which may also be involved in the metabolism of AVK 4
Clinical Implications
The clinical implications of a potential interaction between CBD and AVK are not well understood. However, it is possible that concomitant use of CBD and AVK may increase the risk of bleeding or other adverse effects.
- The study 2 found that clinicians should be aware of the potential interaction between cannabinoids and warfarin, and monitor patients for signs of bleeding or other adverse effects.
- The study 5 found that CBD may interact with a variety of medications, including anticoagulants, and that clinicians should be aware of these potential interactions when prescribing CBD or other cannabinoids.