Mixing Marijuana with Other Drugs

Chances are that you’ve thought about the safety of your marijuana consumption at some point in time. In broad strokes, general perceptions are that marijuana is much safer than drugs like cocaine, heroin, meth, and even alcohol. However, what many people may not realize is that marijuana can interact with other drugs, and that taking them at the same time can lead to undesirable, and sometimes even dangerous, results.

If you read on, we’ll describe the potential interactions of mixing weed with other drugs, to provide a detailed understanding of the risks you’re taking on when you are combining substances.

The classic myth of marijuana as a ‘gateway drug’ for other substance use is controversial. Because marijuana use is just one of hundreds or potential risk factors for other substance use, its exact contribution is difficult to say for certain. While undeniable population trends exist, deciphering the cause-and-effect relationships between marijuana and other risk factors for co-substance abuse is a considerable challenge.

It is true marijuana use has an alarmingly high rate of co-occurrence with other types of substance use. The more you smoke, the stronger association with other substance use becomes. One study found that daily marijuana use was associated with a significant increase in the expected odds of opiate, cocaine, stimulant, hallucinogen, inhalant, and tobacco use (Tzilos, J Addict Dis, 2014). Daily marijuana users have been singled out as being particularly vulnerable to the additive negative consequences associated with polysubstance abuse.

Even so, the association between marijuana use and other substance use doesn’t point to a direct cause and effect. One possibility is that the risk factors that predispose you to using marijuana also predispose you to using other substances. Alternatively, marijuana use may be an independent risk factor for using other drugs (the “gateway drug” hypothesis). Time and more research will tell how much marijuana use directly contributes to likelihood of using other drugs.

There is significant overlap between people who use tobacco and people who use marijuana (Agrawal, Addiction, 2012). A study of 34,653 adults in the United States found that marijuana users, compared with nonusers, were more likely to become cigarette smokers and to develop a moderate to severe tobacco use disorder over the next three years, even after controlling for demographic characteristics and the presence of psychiatric disorders (Weinberger, J Clin Psychiatry, 2018; Blanco, JAMA Psychiatry, 2016).

Co-use of marijuana and tobacco may pose additive risk for toxic exposure–people who smoke both marijuana and tobacco have been shown to have higher breath carbon monoxide levels, and marijuana smoke can have even higher levels of certain carcinogens compared to tobacco smoke (Meier, Drug and Alcohol Dependence, 2016). This increased degree of toxin exposure has the potential to increase your risk for diseases like head, neck or lung cancer.

Alcohol and marijuana are two of the most popular substances in the country and across the globe, so it follows that the two are commonly taken at the same time. As it turns out, the two substances appear to go hand in hand when it comes to risk. One study of 36,309 adults in the United States found that those who had consumed alcohol within the past year were 6 times more likely to report active marijuana use (Kerridge, Addict Behav, 2018). Other studies have shown that a majority of daily recreational marijuana users also binge drink alcohol (Hughes, Psychol Addict Behav, 2016).

Although using marijuana with alcohol does not lead to direct life-threatening interactions, there are particular dangers of co-use that are important to be aware of. When combined, the effects of both alcohol and marijuana add up. This can be enjoyable with low doses and in safe settings, but if too high of a dose of either drug is consumed, the enhanced high can lead to an unpleasant sensation. The informal term you may have heard in reference to this adverse reaction is being ‘crossfaded’, which can include symptoms like nausea or vomiting, head spinning, sweats, anxiety, paranoia. In extreme situations, this combination can even induce panic attacks or frightening hallucinations.

Additionally, marijuana has the ability to suppress the gag reflex, which can impair your body’s ability to vomit and remove excess alcohol when you’ve consumed too much. This opens the door to alcohol poisoning, which has a slew of potentially life-threatening effects, including seizures, trouble breathing, a slowed heart rate, and even coma, permanent brain damage, or death.

You may have heard a common myth that marijuana is the gateway drug to other, ‘harder’ drug use, but this is largely just that–a myth. The majority of people who use marijuana do not, in fact, progress to using ‘harder’ drugs. What’s more likely at play is that environmental and social puts some individuals at an increased likelihood of using many types of drugs, marijuana included. People more likely to take drugs in their lifetime are more likely to start with more readily available substances, such as marijuana or alcohol, and their subsequent interactions with people who use increases their likelihood of expanding on to other illicit substances.

Yet, there is data to support the notion that people who use marijuana are more likely to concurrently use other drugs. One study of U.S. adults found that, compared to people who don’t use marijuana, those who use marijuana are:

These results held up even after controlling for other factors like sociodemographic characteristics, alcohol and cigarette use, and psychiatric diagnoses, further validating how common it is for marijuana to be used with other drugs (Hayley, Eur Neuropsychopharmacol, 2017).
Although research is ongoing to investigate the specific health effects that co-using marijuana with these other drugs can have, it’s important to keep in mind that the risks of addiction potential, negative health impact, and mind alteration associated with each drug you use compound when you use them together. As a general rule–mixing substances is something to be avoided, if possible!