Cannabis and Drug Interactions

Taking one drug when under the influence of another drug is known as polydrug use.

Combining drugs in this way carries extra risks and can be dangerous or even deadly. The more drugs a person takes (or is affected by) at a time, the more chance there is of something going wrong.

Don’t be a statistic. We have seen it happen time and time again where somebody accidentally overdosed because they were not aware of drug to drug interactions. It has happened to many revered celebrities like Taylor Hawkins, drummer for the Foo Fighters, for instance. Hawkins passed away with ten different substances in his system including THC. It certainly didn’t help to add yet another substance to the mix.

Alcohol is the most commonly used drug in America.

When you mix alcohol with other substances including marijuana it can dramatically affect your ability to think clearly.


Alcohol and Marijuana are two of the most commonly used substances in the United States, with 12 perfcent of American adults stating that they smoke marijuana and over 50 percent of American adults saying that they currently drink alcohol. Even if someone is not a current user of alcohol or Marijuana, is it likely that they have tried it at some point; 52 percent of Americans report that they have tried Marijuana and 86 percent report that they have tried alcohol at some point in their lives. Used alone and in moderation, these substances can be consumed safely and legally in certain states. However, when mixed together, alcohol and Marijuana can create unpleasant side effects.

Getting drunk from alcohol and high from Marijuana at the same time is often referred to as being cross-faded.

Prescription medication and street drugs.

Did you know THC can enhance or block the effects of medications? Public Health Muskegon County wants you to know the facts when it comes to using marijuana while on specific medications, recreational drugs or alcohol.

However, if you are on any prescribed medication, recreational drug or under the influence of alcohol, marijuana can most certainly effect you in a negative way. THC uses the same enzyme pathway as many prescription medications and street drugs so they will always interact with one another. This can affect you by blocking the effectiveness of a medication or street drug or significantly increasing it.

Anesthesia and THC

Anethesia interaction—if you’re about to undergo surgery or a medical proceure you want anethesia to work, right?


This is particularly true if you need anesthesia for any medical procedure. Patients who use cannabis even one time per week usually require more than three times more anesthetic medication to achieve adequate sedation.

That’s why it is important to fully disclose any information about cannabis use that your doctor asks for. We know it can be uncomfortable sometimes to talk about cannabis, but withholding information about your consumption could be extremely harmful to you. 

Drug interactions and cognitive skills

Cognitive skills are the core skills your brain uses to think, read, learn, remember, reason and pay attention.


Working together, they take incoming information and move it into the bank of knowledge you use every day at school, at work and in life. Each of your cognitive skills plays an important part in processing new information. That means if even one of these skills is weak, no matter what kind of information is coming your way, grasping, retaining, or using that information is impacted. In fact, most learning struggles are caused by one or more weak cognitive skills. Basically, drug interactions compromise your cognitive skills and therefore effect everything you do on a daily basis. Complete clarity is needed to perform even basic tasks to the best of your ability. This includes driving, working, taking care of children, etc.


What prescription medications are affected by THC?

Any of the following prescription medications can be accelerated or hindered when used in conjunction with THC.

Sedatives — such as Ambien, Lunesta and Benadryl
Anti-anxiety medications — such as Xanax, Valium and Librium
Antidepressants — such as Zoloft, Prozac and Lexapro
Pain medications — such as codeine, Percocet and Vicodin
Anticonvulsants (seizure medications) — such as Tegretol, Topamax and Depakene
Anticoagulants (blood thinners) — such as Coumadin, Plavix and heparin

What should I do if am having a drug interaction reaction?

Call emergency services central dispatch, poison control or go immediately to the nearest emergency room.

(800) 222-1222
Mercy Health Campus Emergency Room
1500 E. Sherman Blvd, Muskegon, MI 49444

What recreational and/or street drugs can be mixed with cannabis?

None. You should never mix substances, particularly illegal ones.