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NIDA. (2018, November 26). How Risky Is It To Combine Drugs? Test Your Knowledge. Retrieved from

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The NIDA Blog Team
November 26 2018

We’ve written a lot on the Drugs & Health Blog about the risks involved with using drugs like marijuana, opioids, cocaine, inhalants, and many others. Does combining the use of two or more drugs at once bring even more risks?

Take the quiz below to learn what can happen if a person uses different drug combinations. Answers are listed after the questions.

True or false?

1. A person who combines opioids with a certain kind of sedative has a higher risk of visiting the emergency room for a drug-related emergency.

2. It isn’t safe to combine the use of tranquilizers or sedatives with some over-the-counter cold and allergy medications, or with prescription pain medicines or alcohol.

3. The risks involved with driving after drinking alcohol and using marijuana at the same time are about the same as the risks involved with either drinking alcohol or using marijuana alone.

4. A person who uses an illegal drug might really be using a potentially deadly combination of drugs.


1. True. Benzodiazepines are a type of prescription sedative sometimes prescribed for anxiety or to help people sleep. (They’re commonly sold under the names Valium®, Xanax®, and Klonopin®.) A person who combines opioids and benzodiazepines is at greater risk for visiting the ER for a drug-related emergency. Plus, at least 30 percent of overdoses involving opioids also involve benzodiazepines. (NIDA)

2. True. Tranquilizers and sedatives or sleep medications like Ambien®, Lunesta®, and Sonata® are all known as “central nervous system (CNS) depressants” because they slow down a person’s brain activity. Prescription pain medicines, some over-the-counter cold and allergy medications, and alcohol are also CNS depressants. So, combining any of these drugs can slow things down way too much, including a person’s heart rhythm and breathing. It can even lead to death. (NIDA)

3. False. It’s seriously risky to drive after drinking alcohol or smoking marijuana, and the risks involved with doing both before driving appear to be even greater. (NIDA)

4. True. There’s no way to know for sure what’s in many drugs sold on the street. For example, street dealers may add the dangerous opioid fentanyl to drugs like heroin, cocaine, and methamphetamine. Fentanyl is 50 to 100 times more powerful than morphine; taking even a small amount of fentanyl can be deadly. (NIDA)

Learn more about the risks of mixing medicines.