Cannabis is a popular recreational drug across the globe, utilized by a substantial portion of the population for its psychoactive properties. Additionally, it has witnessed a growing acceptance in the medicinal community due to its therapeutic benefits. However, the use of cannabis can lead to unintended consequences when combined with certain medications. This article aims to provide an overview of medications that may cause adverse interactions when combined with cannabis.

1. Blood Thinners

The consumption of cannabis, a widely used psychoactive drug across the globe, can lead to potential hazards when combined with certain medications, particularly anticoagulants such as warfarin. It is no secret that numerous medical and recreational users enjoy the plant’s diverse effects, from pain relief to relaxation. However, when cannabis is mixed with other substances, it can introduce a host of unexpected and, in some cases, dangerous interactions. One such perilous interaction occurs with the combination of cannabis and warfarin, a commonly-prescribed anticoagulant. Warfarin is frequently used to treat or prevent blood clots in veins or arteries, which can reduce the risk of stroke, heart attack, or other serious conditions. On the other hand, cannabis, though primarily used recreationally, is also recognized for its medicinal properties, including its potential to reduce inflammation and lower blood pressure. Both substances, when used independently, effectively work by inhibiting the body’s ability to form blood clots. However, when cannabis and warfarin are used concurrently, they may amplify each other’s anticoagulant effects. This is because they may interact in the body’s endocannabinoid system, which is involved in a variety of physiological processes including pain sensation, mood, and memory. The simultaneous use of these substances can potentially exaggerate their individual impacts, leading to various health risks. One of the most concerning risks associated with this combination is the potential for excessive bleeding or bruising. Under normal circumstances, when a blood vessel is damaged, the body responds by forming a blood clot to prevent excessive bleeding. However, when the clotting process is overly inhibited by substances like cannabis and warfarin, it may lead to an increased risk of bleeding. This can manifest as frequent nosebleeds, heavy menstrual periods, blood in urine or stool, or unusually large or frequent bruises. Moreover, in severe cases, this interaction could possibly lead to internal bleeding, which can be a life-threatening condition if not treated promptly. Internal bleeding may not be immediately noticeable, but over time, it can lead to serious complications such as damage to organs or tissues. Therefore, caution must be exercised when combining cannabis with warfarin or any other anticoagulant. In conclusion, while both cannabis and warfarin have their individual uses and benefits, their combined use can usher in potential dangers. Patients who are on warfarin or any other anticoagulants should be transparent with their healthcare providers about their cannabis use. Additionally, healthcare providers should be vigilant in monitoring patients who choose to combine these substances, in order to prevent potential adverse reactions. It is always essential to consult a healthcare provider before starting, stopping, or changing any medication regimen, to ensure safe and beneficial health outcomes.

2. Benzodiazepines

Benzodiazepines represent a class of pharmaceutical drugs intended to serve as a potent tool in the management of a variety of conditions, such as anxiety, seizures, and panic disorders. These include well-known medications like Xanax (generic name Alprazolam) and Ativan (generic name Lorazepam). The primary purpose of these medications is to alleviate intense anxiety by exerting a calming effect on the brain and the central nervous system. They work by enhancing the effect of gamma-aminobutyric acid (GABA), a neurotransmitter in the brain that blocks impulses between nerve cells, thus reducing nervousness and promoting a sense of tranquillity. However, there are concerns regarding the concurrent use of benzodiazepines with other substances, such as cannabis. Cannabis, also known as marijuana, is a psychoactive drug that is commonly used for both recreational and medicinal purposes. It is known to cause relaxation, altered perception, and euphoria. Yet, when benzodiazepines and cannabis are used in conjunction, it may result in heightened sedative effects. This combined use may augment the effects of each substance, leading to a state of prominent drowsiness and significantly decreased motor coordination. As these substances independently can induce a state of sedation and relaxation, their combined use can escalate these effects to an even greater extent. This can lead to an individual feeling excessively fatigued, lethargic or experiencing difficulty in keeping focused. This heightened state of sedation and impaired motor coordination can pose considerable dangers, particularly when performing routine activities that require concentration and alertness. Activities like driving a car or operating heavy machinery can become hazardous. When under the influence of both benzodiazepines and cannabis, the ability to react timely to sudden events often becomes compromised, and the precision required for these tasks can be significantly impaired. This can result in a higher probability of accidents, potentially leading to severe injuries or even fatality. Thus, the concurrent use of benzodiazepines and cannabis is not recommended, especially before engaging in activities that demand alertness and precise motor coordination. While each substance may serve its purpose independently, their combined use can lead to exaggerated effects, potentially leading to unforeseen consequences. Therefore, the co-administration of these substances should be thoroughly discussed with a healthcare professional to avoid any dangerous situations.

3. Antidepressants

For those who suffer from depression, finding the right combination of treatments can be both a vital necessity and a confusing journey. Among the many options available, some individuals discover that cannabis offers them relief, managing their symptoms of depression effectively. The plant’s potent chemical compounds, such as THC and CBD, are lauded for their ability to mitigate feelings of despair, anxiety, and fear, which are common symptoms of depression. While the use of cannabis for depression is not yet universally accepted in the medical community, anecdotal evidence and some research studies suggest its potential effectiveness in treating this mental health disorder. However, it is crucial to note that the combined use of cannabis and antidepressants – a common class of prescribed medication for depression – can yield unpredictable effects. Many antidepressants function by balancing the brain’s neurotransmitters, chemicals that transmit signals between nerve cells. For some, introducing cannabis into this delicate balance might lead to an amplification of the drugs’ effects. This could potentially result in a variety of outcomes, some of which may not be desirable. For instance, one potential outcome of this combination could be an increase in drowsiness. Many antidepressants already list fatigue as a common side effect, and given that certain strains of cannabis are known to induce sleepiness, this effect may be augmented when both are used concurrently. This excessive drowsiness could interfere with daily activities, making it difficult for individuals to stay alert and focused during the day. Moreover, in some unfortunate cases, the interaction between cannabis and antidepressants may even heighten feelings of depression. Instead of providing relief, this combination could inadvertently exacerbate symptoms, leading to a deeper sense of despair or a more severe depressive episode. This may seem counterintuitive given that both substances are used separately to manage depression. However, given the complexity of the brain’s neurotransmitter system and the diverse ways that cannabis and antidepressants interact with it, these severe outcomes can occur. In conclusion, while cannabis has been found by some to help manage depression symptoms, combining it with antidepressants can have unpredictable effects that could potentially amplify the symptoms they are intended to treat. It is therefore crucial that individuals seeking to utilize this combination for their depression treatment approach it with caution, informed knowledge, and under the supervision of a healthcare provider. Moreover, this underscores the importance of further research into the interactions between cannabis and other pharmaceuticals to ensure that those seeking relief from mental health disorders can do so safely and effectively.

4. Opioids

Opioids, including but not limited to morphine and oxycodone, are frequently prescribed by medical professionals as effective means of pain relief. They have long been considered a critical part of the medical toolkit, particularly when it comes to managing acute pain that results from surgery, injuries, or debilitating chronic conditions like cancer. Despite their benefits, opioids have a dark side, namely the potential for addiction and dependence, which has led to what is commonly referred to as the opioid epidemic. However, another concerning aspect that needs to be carefully considered is the combination of these potent drugs with cannabis. While cannabis is gaining more recognition and acceptance in several parts of the world for its potential medicinal benefits, especially in managing chronic pain and certain mental health conditions, it’s crucial to comprehend the implications of using it concurrently with opioids. The issue arises from the fact that both opioids and cannabis act on the central nervous system. They are known as central nervous system depressants, meaning they slow down brain function. This effect can lead to several potentially detrimental health consequences. One of the most immediate and dangerous consequences is difficulty breathing. Both opioids and cannabis can cause the rate of breathing to slow dramatically or even stop altogether. This is because these substances impair the brain’s ability to control the body’s breathing. In severe cases, where large quantities of these substances are ingested, it can lead to hypoxia – a condition characterized by an insufficient supply of oxygen in the tissues to sustain bodily functions. Hypoxia can have long-term neurological effects and can also be fatal. Another possible outcome of using opioids and cannabis concurrently is extreme drowsiness. This can be particularly problematic, as it can lead to accidents or injuries. For instance, if a person under the influence of these substances attempts to drive or operate machinery, they put themselves and others at significant risk. Perhaps the most terrifying potential consequence of this combination is the risk of a life-threatening overdose. As both of these substances depress the central nervous system, using them together can amplify their effects, making it easy to unintentionally take a lethal dose. This risk is further exacerbated by the fact that individuals often have differing tolerance levels to these substances, and what might be a manageable dose for one person could be fatal for another. In conclusion, while opioids and cannabis may both have their place in medical treatment, combining these substances can lead to serious and potentially fatal health consequences. It’s essential that individuals discuss all medication use, including cannabis, with their healthcare professionals before starting any new treatment regimen. It is also important to remember that the safest choice is always to follow prescribed dosages and to never mix medications without medical consultation.

5. Alcohol

Although not technically a medication, alcohol’s common use warrants its mention. Combining alcohol with cannabis can heighten the effects of both substances, leading to increased impairment. This combination can increase the risk of accidents and injuries and can also lead to more severe health issues such as alcohol poisoning.

6. Certain Antiviral Drugs

Several antiviral medications, particularly those employed in the treatment of Human Immunodeficiency Virus (HIV), can have negative interactions with cannabis, leading to potentially diminished therapeutic effects and undesirable health outcomes. HIV, a life-threatening retroviral infection, sadly remains a global epidemic despite medical advancements. Its treatment typically involves a cocktail of antiretroviral drugs administered via comprehensive antiretroviral therapy (ART), aimed at reducing viral replication within the body, maintaining immune system function, and improving the quality and longevity of the patient’s life. However, the co-consumption of cannabis with these antiretroviral medications has been found to potentially interfere with the therapeutic effects of the drugs, leading to a significant health concern for patients. While the therapeutic properties of cannabis have been recognized for a variety of conditions, including chronic pain, multiple sclerosis, and epilepsy, its interaction with certain antiretroviral drugs can have undesirable consequences. Cannabis, also known as marijuana, is a complex plant with over 400 chemical entities of which more than 60 are cannabinoid compounds. These compounds interact with cannabinoid receptors in the brain and the immune system, influencing various physiological processes such as appetite, pain sensation, mood, and memory. When combined with antiviral therapies, particularly those for HIV, these interactions can disrupt the efficacy of the antiretroviral drugs. For instance, certain antiretroviral medications in the regimen may see their therapeutic effects reduced due to the pharmacokinetic changes induced by cannabis. This could involve alterations in drug absorption, metabolism, distribution, and excretion. Such changes can lead to decreased plasma concentrations of the antiretroviral drugs, reducing their effectiveness in inhibiting HIV replication. This potential reduction in drug effectiveness can lead to an increase in the viral load within the body, which is an indicator of the severity of the HIV infection. A higher viral load equates to a higher concentration of the virus in the body, implying a more active and progressive infection, and a higher chance of transmission to others. Moreover, the decreased efficacy of antiretroviral therapies due to cannabis interaction could lead to a diminished immune response, making the individual more susceptible to opportunistic infections and diseases. HIV already compromises the immune system, and any factor that further weakens the immune response can have severe repercussions on the patient’s health. Thus, it is imperative for patients and healthcare providers to be aware of these potential interactions and closely monitor the use of cannabis in conjunction with antiretroviral therapies. This awareness can help in optimizing therapy, managing potential drug interactions, and ultimately ensuring the best possible health outcomes for individuals living with HIV.

Conclusion

While it’s true that cannabis is widely recognized for its potential medicinal properties, we cannot simply ignore the fact that it has been found to interact negatively with various other medications. The multiple components of cannabis, such as THC and CBD, which are beneficial in treating a range of symptoms, can inadvertently interfere with the effectiveness or potency of other drugs. Therefore, it is of paramount importance to exercise caution when considering combining cannabis with any other medications. The significance of discussing your intentions to use cannabis, especially for medicinal purposes, with your healthcare provider cannot be overstated. Experienced medical practitioners, such as your personal doctor or a trained pharmacist, possess a comprehensive understanding of how different substances can interact within your body. Therefore, they should always be your first point of contact before making any changes to your existing regime of medications. Understanding the potential risks and side effects associated with using cannabis in conjunction with other medications can empower patients to make informed decisions about their health and well-being. Complications can range from minor inconveniences, such as drowsiness or a dry mouth, to more severe health implications, like increased heart rate or lowered blood pressure. Being properly equipped with knowledge about these possible ramifications can help patients to weigh the potential benefits against the possible side effects, thereby allowing them to make choices that best suit their individual health needs. Another crucial aspect to bear in mind is the variability inherent in different strains of cannabis. Cannabis is a complex plant with hundreds of variables that can have different effects on the body. The potency, method of consumption, and individual differences can all contribute to a unique experience for each user. Consequently, what works for one person in terms of relief or therapeutic benefit may not necessarily produce the same results for another. This further emphasizes the significance of guidance from a healthcare professional when using cannabis, particularly for medicinal purposes. Ultimately, the use of cannabis, particularly for therapeutic purposes, should always be approached with due diligence and under the guidance of a healthcare professional. The complexities of cannabis and its interactions with other medications underscore the need for professional advice to ensure safe and effective use. While the potential health benefits of cannabis are indeed promising, it is essential to remember that like any other medication or substance, it must be used responsibly and in a controlled manner to maximize its benefits and minimize potential risks.

Cannabis is a plant that contains many compounds that can affect the body and mind in various ways. Some of these compounds, such as THC and CBD, can interact with other medications that you may be taking, causing adverse reactions or changing their effectiveness. It is important to be aware of the possible interactions between cannabis and your medications, and to consult your doctor before using cannabis for medical purposes.

Some of the medications that can cause adverse reactions with cannabis are:

– Anticoagulants and anti-platelet drugs, herbs and supplements. These are substances that reduce blood clotting, such as warfarin, aspirin, clopidogrel, ginkgo biloba, and garlic. Cannabis can also affect blood clotting, and may increase the risk of bleeding if used with these substances¹.

– CNS depressants. These are drugs that slow down the central nervous system, such as benzodiazepines, opioids, barbiturates, alcohol, and antihistamines. Cannabis can also have sedative effects, and may increase the risk of drowsiness, confusion, impaired coordination, and respiratory depression if used with these drugs¹.

– Protease inhibitors. These are drugs that treat HIV infection, such as ritonavir, indinavir, saquinavir, and nelfinavir. Cannabis can interfere with the metabolism of these drugs by the liver enzyme CYP3A4, and may increase their blood levels and side effects¹.

– Selective serotonin reuptake inhibitors (SSRIs). These are drugs that treat depression and anxiety, such as fluoxetine, sertraline, paroxetine, and citalopram. Cannabis can also affect serotonin levels in the brain, and may increase the risk of serotonin syndrome if used with these drugs. Serotonin syndrome is a potentially life-threatening condition that causes symptoms such as agitation, confusion, tremor, muscle rigidity, fever, and seizures¹.

– Cytochrome P450 enzymes. These are enzymes that metabolize many drugs in the liver. Cannabis can inhibit or induce some of these enzymes, such as CYP3A4 and CYP2C9, and may alter the blood levels and effects of the drugs that are metabolized by them. Some examples of these drugs are warfarin, phenytoin, diazepam, omeprazole, clopidogrel, and codeine².

These are not all the possible interactions between cannabis and other medications. You should always check with your doctor or pharmacist before using cannabis with any prescription or over-the-counter drugs, herbs, or supplements. You should also monitor your symptoms and side effects carefully when using cannabis with other substances. Cannabis may not be safe or effective for everyone, and may cause unwanted or harmful effects in some people.

Source: Conversation with Bing, 11/10/2023

(1) Marijuana – Mayo Clinic. https://www.mayoclinic.org/drugs-supplements-marijuana/art-20364974.

(2) . https://bing.com/search?q=medications+that+cause+adverse+reactions+with+cannabis.

(3) Cannabis Interactions Checker – Drugs.com. https://www.drugs.com/drug-interactions/cannabis.html.

(4) Medical Cannabis: Adverse Effects & Drug Interactions. https://doh.dc.gov/sites/default/files/dc/sites/doh/publication/attachments/Medical%20Cannabis%20Adverse%20Effects%20and%20Drug%20Interactions_0.pdf.

(5) Medical Marijuana Drug Interactions: A Doctor’s Perspective. https://greenhealthdocs.com/medical-marijuana-drug-interactions/.

(6) undefined. https://www.nhs.uk/conditions/medical-cannabis/.

(7) undefined. https://www.medicalnewstoday.com/articles/study-suggests-frequency-and-severity-of-negative-reactions-to-cannabis.

(8) undefined. https://news.wsu.edu/press-release/2021/12/13/cannabis-use-could-cause-harmful-drug-interactions/.