Mounting research and anecdotal evidence show promising therapeutic uses for cannabis. But with many touted benefits come some noteworthy risks, like prescription drugs reacting negatively with the plant. There is a lot to consider before mixing a garden gummy or weed drink with a daily medication. One may ponder whether it is better to mix some drugs over others, or how to temper consumption while on antibiotics. Research on the topic needs more development, but this comprehensive report on weed and prescriptions is a good place to start.
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When two drugs impact one another, for good or bad, this is labeled a drug interaction. In some cases, the effects of the compounds in each drug may become more intense when combined. Other drugs may cancel each other out.
There are almost 400 potential drug interactions with cannabis, 28 of which are considered “major.” Many sedatives, anti-anxiety meds, antidepressants, pain medications, anticonvulsants, and anticoagulants make the list.
Dr. HaVy Ngo-Hamilton, pharmacist and clinical consultant for BuzzRx, shared more about cannabis contraindications.
“It is vital to remember that any drug interactions, when combined cannabis and other medications, can potentially lead to severe health complications,” HaVy Ngo-Hamilton said, “The severity of the adverse effects is influenced by various factors, including dosage, age, kidney, and liver function, and overall health status.”
When deducing whether a prescription drug could interact with weed, looking at the active compounds is essential. Active compounds are the compounds in a medication or drug that affect a person. In weed, the most prominent are called “cannabinoids,” and different ones may have unique interactions.
Drug contraindications and cannabinoids
The cannabis plant naturally produces over 100 cannabinoids like THC, CBD, THCV, CBN, and so many more. These compounds interact with the endocannabinoid system, which modulates anxiety, digestion, and more.
Dr. Tracy Brooks, associate professor and Chair of Pharmaceutical Sciences for the School of Pharmacy and Pharmaceutical Sciences at Binghamton University, weighed in on the two most common cannabinoids.
“Both THC and CBD are, themselves, metabolized by two major proteins—CYP 3A4 and 2C9. 3A4 is the metabolizer of about 50 percent of all prescription medications taken, and there can be competition for metabolism,” Brooks said.
Metabolization refers to how the body digests drugs, a process responsible for the depth of effects. If the body is metabolizing cannabis, it may not have as much space in the queue to fully metabolize a prescription pharmaceutical, too. When too many compounds attempt to bond to an enzyme site it can lead to enzyme inhibition. This could lead to serotonin syndrome, tachycardia, and hypertension.
Taking these two medications together may make either or one less effective, it could also be dangerous. The severity of this experience depends on cannabinoid content, how much cannabis they had, and when. These interactions could change how intense or effective one or both drugs are, impacting medication efficacy. All cannabinoids potentially compete with other pharmaceutical compounds, but they also have varying impact on specific medications.
Weed interacts with all pharmaceuticals in particular ways. It is vital to look up specific drugs and their cannabis contraindications for a focused risk assessment.
Specific pharmaceuticals and weed
Anyone on prescribed medications should consult their doctor about cannabis use and potential contraindications before rolling up. However, consuming cannabis while taking some specific medications is known to carry especially high risk. Here are some, but not all, notable examples:
Sedatives and cannabis
Mixing weed with sedatives is not recommended. These drugs depress the central nervous system (CNS), and cannabis may have sedative effects. That is a recipe for excess drowsiness.
Combining the plant with a prescription sedative or hypnotic could increase sedation, cause respiratory distress, “dangerously low blood pressure,” confusion, impaired motor function, slurred speech, or even death. This impairment experience may also be addictive.
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Antidepressants with weed
Patients have reported that cannabis helps them manage depression, though misuse can also worsen the condition. This balancing act is complicated, but those who are already on selective serotonin reuptake inhibitors (SSRIs) may want to heed further warning.
“Cannabis can increase blood levels of many SSRIs antidepressants, such as fluoxetine and sertraline, causing dizziness, agitation, anxiety, and restlessness. Serotonin syndrome, a rare but severe complication, occurs when there is a dangerously high level of serotonin in the body,” said Ngo-Hamilton.
Anyone taking antidepressants should be in communication with a doctor when consuming cannabis recreationally or medically.
Cannabis and antipsychotics
Both experts warned about combining antipsychotics with weed as the combination could negate treatment.
“Antipsychotics, such as risperidone, can impair cognitive function and exacerbate psychiatric symptoms such as psychosis when taken with cannabis,” Ngo-Hamilton said.
Antipsychotics help people manage bipolar disorder, some presentations of depression, psychosis, anxiety, and Tourettes Syndrome. Consuming cannabis may negatively interact with this medicine, possibly greatly disrupting quality of life.
Weed and blood thinners
Blood thinners, also known as anticoagulants, reduce the risk of heart attack, stroke, and blood clots in patients. Consuming cannabis while taking them, specifically a drug called warfarin to treat blood clots, is dangerous.
Taking warfarin creates a “high bleeding risk.” If someone is injured or falls while it is in their system, it could lead to potentially fatal internal bleeding. Cannabis increases blood levels, which could also intensify the bleeding in the event of injury.
“Both THC and CBD can increase the levels of warfarin in the body, leading to decreased clotting ability and a risk of bleeding,” Brooks added.
Bottom line: avoid taking these substances together.
Cannabis and stimulants
People with ADHD (Adderall, Ritalin, etc.) are stimulants, and they are sometimes prescribed to people with depression or chronic fatigue. They are used by a “very high percentage of the population,” with some abusing the pharmaceuticals for bursts of energy or quicker reaction times. Do not consume these drugs with cannabis, especially without a conversation with the prescribing doctor.
Heart rate can increase immediately after inhaling weed smoke, which might make taking amphetamines and other stimulants dangerous. Taking weed with stimulants could lead to anxiety verging on severe, racing heart, or impaired focus. These symptoms are potentially life-threatening. Do not take these at the same time.
Blood pressure meds with weed
Lots of different prescription hypertensives help modulate blood pressure. Inhaling or ingesting cannabis may severely increase blood pressure, especially in higher doses.
“Beta-blockers, such as metoprolol, propranolol, and other anti-hypertensive agents are designed to lower blood pressure and heart rate,” said Ngo-Hamilton. “Combining blood pressure medications with cannabis may further reduce blood pressure and heart rate, leading to serious consequences if left untreated.”
Mixing these compounds is not recommended.
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Lennox-Gastaut treatment bares warning
Lennox-Gastaut is a severe epilepsy that presents when children are around two years old. These kids have multiple kinds of seizures, developmental delays, and unique brain patterns. The syndrome currently has no cure, but many children are prescribed seizure medication to manage it.
Clobazam is a sedative prescribed to Lennox-Gastaut patients for seizures, but some families are turning to cannabis instead. Whichever treatment the doctor and family decide on, the two options should never be combined. Cannabinoids may increase clobazam levels. This interaction may cause confusion, severe drowsiness, sleepiness, and lethargy.
Those caring for children with Lennox-Gastaut should never try cannabis without first consulting their doctor. This is especially true for those prescribed other drugs.
Weed and prescriptions: not worth the risk
Patients of all ages around the world have expressed that medical cannabis helps them manage symptoms and increase their general quality of life. However, these benefits are obsolete when other medications enter the fold. Cannabis may not play nice with prescriptions, creating complications that could lead to severe consequences. Essentially, everyone on meds should consult a doctor before lighting up.
“If you have been using cannabis or any cannabinoid-containing products, it is crucial to discuss this with your doctor or pharmacist to ensure it’s safe for you. Maintaining an open and honest line of communication with your healthcare provider is not just important, but empowering,” Ngo-Hamilton concluded.
