Whether doctors approve or not, mixing cannabis with other substances is commonplace. Recreationally, people love to consume cannabis with alcohol, tobacco, or other drugs. Medicinally, patients often combined with pharmaceuticals. Combining cannabis with these other substances can affect your body in ways you might expect, and it’s not always pleasant.
First, let’s get a few important points out of the way. This article is for educational purposes only, it is intended to inform you about some of the known consequences of combining cannabis with other substances This article is not intended to diagnose any illness or adverse reaction. If you have questions about how cannabis and prescriptions interact, it’s best to speak with your physician.
Now, let’s explore how cannabis changes alcohol, prescriptions, and tobacco.
Cannabis and Alcohol
This combo is practiced at every cannabis-friendly party in the world. Drinking and smoking are favorite party companions. However, there are certain aspects of this that most people don’t consider.
When you drink and smoke cannabis, you’ll feel the effects of both more strongly. According to a recovery center, “When people drink and then smoke weed afterward, they have also been shown to have much higher amounts of THC in their blood as opposed to people who didn’t drink. The reason for this appears to be because alcohol widens the blood vessels in the gastrointestinal tract, allowing for the faster absorption of the THC.”
So you can see how this could be a problem. If you’re two to three drinks in and you smoke a joint, your body will actually absorb THC more rapidly. You may feel a more significant “rush,” then when you smoke alone. Also, the THC will alter the effects of alcohol. Which means you may feel less or more drunk than you really are.
This is problematic, especially in people who may be unfamiliar with intoxication. The effects of alcohol intoxication can be deadly, so it’s crucial to limit yourself, and only mix in small amounts. Otherwise, you may find yourself blacking out, or worse. Very clearly, there is an intensification of the experience.
Scott Lukas, a professor of psychiatry and pharmacology at Harvard Medical School, has studied this experience in depth. In a piece for Vice, author Thor Benson goes into Lukas’ research to describe how cannabis alters the motility of the intestines, which then changes the blood-alcohol levels. Based on the research, Benson comes to the conclusion, “If you drink first and then smoke, it causes the levels of THC in your plasma to skyrocket, intensifying your high. That’s because alcohol opens up blood vessels in your digestive system, which helps THC get absorbed—a finding confirmed in a more recent study done in 2015.” 
According to the authors of “Medicinal Cannabis—Potential Drug Interactions,” cannabis and alcohol mix in problematic ways. They explained, “A study in 32 adult cannabis smokers found that low-dose alcohol (approximately 0.065% peak breath alcohol concentration) increased blood levels of THC, which may explain the performance impairment observed from a cannabis–alcohol combination”
So if you’re thinking about mixing cannabis and alcohol, keep in mind that they will affect each other, and possibly dramatically so. It’s best to proceed with extreme caution when mixing any substances together intentionally. While it might sound like fun, and maybe was even fun on previous experiences, combining the substances can lead to significantly impaired judgment as well as a heavily altered state of mind. Stay safe and stick with one substance at a time.
Cannabis and Prescription Drugs
If you’re taking prescription drugs, you may be curious to know whether or not you can use cannabis as well. Depending on your particular situation, you’ll most likely want to consult with your doctor before combining your prescription drugs with cannabis. In many combinations, there are no known interactions, but in others, there are certain concerns.
According to Leafly, “Both THC and CBD may increase the effect of drugs used for blood thinning (e.g. warfarin or heparin), or drugs known to carry their own risk of blood thinning (e.g. ibuprofen, naproxen, etc.). How? By possibly slowing down the metabolism of these drugs. To a lesser extent, THC may displace warfarin from protein binding sites.”
So if you’re taking a blood-thinning medication, your blood may become thinner than expected, because the drug remains in your system for longer. In some cases, it is easy to see how this could become a problem, especially if you are consuming the medication regularly and, at the same time, consuming cannabis regularly.
A piece by John Murphy mentions the drugs Theophylline, Clobazam, and Valproate and states the following about how cannabis interacts with these medications:
- “Taking CBD with valproate can raise liver enzyme levels and may cause liver injury.”
- “Theophylline is…used for treating symptoms of asthma, bronchitis, emphysema, and other lung diseases. Marijuana…may hasten the metabolic clearance of theophylline, potentially lowering the drug’s effect.”
- “CBD increases the effects and the side effects of clobazam, a benzodiazepine indicated for treating seizures associated with Lennox-Gastaut syndrome in children and adults… So, when these two drugs are used together, the CBD interaction contributes to clobazam’s efficacy, resulting in a three-fold increase in the plasma concentration of clobazam’s active metabolite. The downside is that this interaction also increases clobazam’s side effect of sedation. As a result, clinicians are advised to lower the dose of clobazam when used in conjunction with CBD.”
So clearly, your body may react differently to prescription medications if you mix them with cannabis. Consult with your doctor when refilling your prescription to determine whether cannabis use is a cause of concern. Will adding in cannabis cause an adverse reaction to your current medication?
Cannabis and Tobacco
Cannabis and tobacco rolled into a spliff is a popular route of administration. The combination is known far and wide and by many names. Many thrifty connoisseurs have found that mixing cannabis with tobacco is a good way to make your green last. But this isn’t the only reason. Some people claim that tobacco increases the high
According to Ruchira Sharma, for Vice, “Smoking weed with tobacco doesn’t improve the high, according to new research conducted by UCL and running counter to the long-held stoner myth that a drop of baccy will somehow magnify the effects of the cannabis. However, it’s not all bad news: the study found that the combination may actually reduce the damaging effects cannabis can have on memory.” Sharm goes on to state that “…Smoking a mixed tobacco and cannabis spliff can temporarily increase blood pressure and heart rate…”
So if it doesn’t make the high better, does it have any real benefits beyond stretching out the stash? Igor Grant for the Center for Brain Health at the University of Dallas, Texas, says:
“Hippocampal size of nonusers reflects a direct relationship to memory function; the smaller the hippocampus, the poorer the memory function. Individuals who use marijuana and tobacco show an inverse relationship, i.e., the smaller the hippocampus size, the greater the memory function.”
Furthermore, “The greater the number of cigarettes smoked per day, the smaller the hippocampal volume and the greater the memory performance.” So it seems combining tobacco with cannabis can have beneficial effects for one’s memory.
While this memory-boosting property is interesting to consider, does it outweigh the risks of smoking tobacco? Tobacco is a known carcinogen and highly addictive. For small improvements to memory over the short term, is it worth the risk to your respiratory tract? Likely not.
A Final Word on Cannabis Interactions
Remember, combining cannabis with other drugs can lead to unexpected experiences. Different combinations alter natural and biological chemistry for unpredictable results. Practice sensible consumption and know that cannabis and other mind-altering substances are not to be taken lightly. Always consult your doctor before combining cannabis with any pharmaceutical, as it may require adjustment to your current prescription and careful monitoring for changes in relief.