Why Is Mixing Drugs So Dangerous?


All too often, the headlines are filled with news of celebrity deaths as a result of drug overdose: Carrie Fisher, Whitney Houston, Michael Jackson, and countless others. Drug overdose is the leading cause of accidental death in the U.S. — and most fatal overdoses involve more than one type of drug (“polydrug use”).

According to the American Society of Addiction Medicine, opioid addiction is driving this drug overdose epidemic. But when it comes to mixing drugs, opioids are not the only concern. You don’t even have to be an addict to fall victim to common drug mixing mistakes.

Why is it risky to combine drugs?

When a doctor prescribes a medication, you both can predict the risks and the effect the drug will have on your body. But when you add another drug to the mix — prescription, over-the-counter, or recreational — the combined effect on the body gets more complicated, Indra Cidambi, M.D., an addiction medicine expert, tells HealthCentral. In many cases, combining two drugs can alter or intensify their effects, making them dangerous or even life-threatening. “Drug cocktails” of more than two drugs are even more risky.

Why do people mix drugs?

People use multiple drugs at once for several different reasons, Dr. Cidambi says. For example, they may want quick relief from the problems that are experiencing.

“‘I'm anxious: Give me an anti-anxiety medication. I'm not able to sleep: Let me take a sleeping pill. I'm too depressed: Give me an antidepressant to make me feel better,’” she says. “So it's tough. It's really difficult to practice medicine the right way. … It takes time.”

In other scenarios, people mix drugs with the goal of getting a better high, Dr. Cidambi says — to self-medicate or to enhance the effect of another drug they are taking. And in some cases, people may combine drugs to reduce the negative effects of coming down from a particular drug. For example, someone who has used ecstasy may also use marijuana to fight off the nausea and insomnia that may come with the ecstasy withdrawal, Dr. Cidambi says.

Still others may mix drugs to negative effect without even realizing they are doing it.

For those not using illegal drugs, what are the most common drug-mixing mistakes?

Taking two prescription medications at once can be harmful and even life-threatening, depending on the combination, Dr. Cidambi says. For example, say you are taking a prescribed antidepressant, but you feel it’s not working well enough, so you decide to try another kind of antidepressant at the same time.

“It can spike the blood pressure. Mixing those two is detrimental to life, and [the person] might end up in the emergency room,” she says.

Mixing any prescription medication with alcohol can be dangerous, too. Even certain over-the-counter medications mixed with alcohol can be harmful. For example, having a few alcoholic drinks while taking acetaminophen can cause severe liver damage.

How can we reduce our risk of harm from mixing drugs?

The only time you should take more than one drug at once is if you have a doctor’s clear approval that the combination is safe. This is why it’s especially important to communicate honestly with each member of your health care team about the medications you are taking and your alcohol and recreational drug use habits, Dr. Cidambi says. For example, if you see a cardiologist and a psychiatrist in addition to your general practitioner, the three physicians need to be aware of what the others are prescribing to avoid harmful combinations.

“In my practice, I always ask [patients], ‘What medications are you on? Bring those bottles in,’ and I will be able to see if they are taking it in the right way,” Dr. Cidambi says.

Health care professionals can also help educate patients about the availability of emergency help in situations when drug mixing goes awry.

While doctors play a major role in ensuring patients aren’t mixing prescription drugs dangerously, Dr. Cidambi says, you as the patient can also be proactive by making sure you aren’t leaving out any information at your doctor’s visits.

“I think that's the most important thing — to communicate,” Dr. Cidambi says.

Additionally, make sure you are always reading the labels on your medications and ensuring you are taking them properly and according to your provider’s instructions. When in doubt, call your doctor or ask your pharmacist.

Finally, don’t assume that a certain combination of drugs is safe just because you’ve done it before without detrimental effect.

“People always think, ‘I've been doing this and nothing really bad has happened so far,’” Dr. Cidambi says. “And so I always tell my patients, ‘Listen, if you drive 80 miles per hour, not every time you’re getting into an accident or stopped by cops — but when it happens, it happens.’”

Examples of dangerous drug interactions

The following are examples of drug combinations that can be harmful:

  • Alcohol and recreational/street drugs:
  • Alcohol and cocaine: Increases heart rate and weakens muscles in the heart. May increase violent thoughts. Increases risk of overdose and sudden death.
  • Alcohol and heroin: Slows heart and breathing rate. Increases risk of respiratory failure, coma, and death.
  • Marijuana and alcohol: Increases heart rate and blood pressure. Intensifies slowing effect on mental processes and reaction time.
  • Alcohol and prescription stimulants (e.g. amphetamines like Adderall, methylphenidates like Ritalin): Increases heart rate and heart complications. Hides the depressant effect of alcohol, increasing the risk of overdose. May increase blood pressure and jitters.
  • Alcohol and prescription opioids (e.g. codeine, hydrocodone, oxycodone): Slows heart and breathing rate. Increases risk of death.
  • Alcohol and prescription sedatives (e.g. sleeping medications, benzodiazepines like Xanax or Valium, or barbiturates like Luminal): Intensifies sedative effects. Slows heart and breathing rate, which can lead to death.
  • Heroin and cocaine: Increases risk of respiratory failure and death.
  • Mixing prescription drugs: Increases risk of serious side effects, including fatal overdose.

See more helpful articles:

CDC Sends Money to States to Fight Opioid Crisis

Everything You Need to Know About Opioid Medications

8 Dos and Don’ts for Opioid Safety

Did Xanax Kill Whitney Houston?