The Deadly Dangers of Polydrug Use

Polydrug use

Several years ago, I had the opportunity to review a summary of all the drugs taken by a particular group of people entering rehab. This compilation included reports from 70 people, men and women, average age 31, with ages ranging from 18 to 65. I was astonished at the long lists of drugs most of these individuals had consumed.

Lists of drugs 10 to 15 substances long were common; some ran to 20 or even 25. Most people sampled every category of drug from cannabis to sedatives and opioids plus alcohol.

Of these 70 people, only two had just one drug on their list: one with heroin and one with OxyContin. Only a small handful had skipped opioids. Similarly, nearly all of them drank excessively for periods of time. And it was rare that these individuals avoided marijuana.

It’s true that drug users are not, by and large, careful about their health. But what these individuals did not always take into account is that some of their drug combinations are far more likely to kill them than any of the individual drugs they may have used.

The list of well-known people who have died with multiple drugs in their systems is appallingly long. Some of these people were combining illicit drugs. Others were combining illicit drugs with others their doctors prescribed. Or they were abusing or mixing illicitly-obtained prescription drugs or combining them with illicit drugs.

Mac Miller
Mac Miller (Photo by Jack Fordyce/

Here are a few of the individuals you may have heard of who lost their lives to polydrug use:

Polydrug use is always a dangerous practice that can easily turn deadly.

Defining Polydrug Abuse

The World Health Organization defines polydrug use as using multiple drugs at the same time, using them sequentially or using more than one drug or type of drug, with addiction to at least one of these drugs.

Let’s take a closer look at these categories.

  • Sequential Use: A person will use different drugs at different times. For example, heroin in the evening before they go to sleep. Then they’ll use cocaine or methamphetamine in the morning to get themselves active. Some people will leave the morning drug by the bedside so they have it ready as soon as they wake up.
  • Simultaneous Use: Mixed drug consumption is very common. A person who drinks may also use cocaine so they don’t experience the sedating effects of alcohol. Thus, they can keep partying. A mixture of cocaine and heroin is referred to as a speedball and has killed many people. Marijuana and alcohol are often used together in recreational settings.
  • Opportunistic Use: Those individuals who lack steady drug supplies may use whatever drug they can get their hands on. The constant in their lives is the need for some substance to alleviate the pain or stress they feel from their lives. Therefore, they may mix whatever drugs they can acquire to create the effect they are seeking.
  • Unintentional Use: Let’s face it, drug dealers are not licensed chemists. A dealer who cuts heroin to increase the number of bags he can sell will use whatever is cheap and available, which could be another dangerous drug.

A person who buys heroin never gets pure heroin. His bag of drugs may contain some heroin plus baking soda, sugar, baby formula, over-the-counter painkillers, talcum powder, caffeine or rat poison.

Fentanyl has been found in heroin supplies across the country, causing accidental overdoses because of fentanyl’s greater potency. Xylazine (a veterinary sedative and pain reliever) is a recent addition to the list of adulterants that magnifies the dangers of using drugs like heroin, fentanyl or cocaine. This drug has become such a popular cutting agent that it was found in one-third of fatal overdoses in Philadelphia in 2019.

Combinations and Their Effects

Some mixtures create dangers all out of proportion to the danger of consuming a single drug. Let’s look at some of these combinations.

Man feels dizzy from polydrug use

Alcohol and benzodiazepines: A benzodiazepine is a category of anti-anxiety drugs that includes Xanax, Librium, Valium, Paxil and many others. While these are, of course, prescribed by doctors, they are also very commonly abused drugs. A person who mixes alcohol and benzos risks effects such as the following:

  • Drowsiness
  • Dizziness
  • Slowed breathing
  • Loss of motor control
  • Memory loss
  • Greater risk of overdose

Alcohol and “study drugs”: Around the country, the misuse of so-called study drugs is common because of the students’ belief that it will help them succeed in their studies. If a student then hangs out with friends and drinks, he or she could experience these effects:

  • Dizziness
  • Drowsiness
  • Poor concentration
  • Liver damage
  • Heart problems

Alcohol and cough medicine: There are certain groups that favor the misuse of cough medicine for recreational purposes. Most of these individuals mix their cough medicine with soda drinks but a few add alcohol. These people risk these effects:

  • Dizziness
  • Drowsiness
  • Greater risk of overdose

Alcohol plus opioid pain relievers or illicit opioids: Both alcohol and opioids are central nervous system depressants. If a person consumes these drugs together, they can experience some very serious effects. It’s important to remember that many prescription opioids are formulated to be long-lasting. This means that their effects will linger which can fool a person into thinking they are safe to drink large quantities of alcohol if it has been a while since they consumed an opioid. The effects of this combination:

  • Drowsiness
  • Dizziness
  • Greater risk of overdose
  • Difficulty breathing
  • Loss of motor control
  • Loss of memory
  • Coma
  • Death

Alcohol and cocaine: Using these two drugs together results in the creation of a new and dangerous chemical in the body, cocaethylene. This chemical is associated with liver damage, seizures and reduced functioning of the immune system. There’s a much greater risk of death when these two drugs are consumed together.

Alcohol and GHB:

  • Greatly increased central nervous system depression
  • Nausea
  • Difficulty breathing

Alcohol and marijuana: These drugs combined slow a person’s mental processing and reaction time. Driving while impaired by either marijuana or alcohol increases one’s risk for accidents, but driving while impaired by both drugs boosts this risk even higher.

Cocaine and amphetamine/cocaine and ecstasy/cocaine and prescription stimulants: As all these drugs are strong stimulants, a person using two (or more) at the same time risks a deadly overdose as they place enormous stress on the cardiovascular system.

Cocaine and heroin: This popular combination is called a speedball. Those using this combination hope to get the most desirable aspects of each drug’s effects while reducing the dopiness of the heroin. Instead, the user may suffer confusion, blurred vision, paranoia, loss of motor skills, stroke, heart attack or respiratory failure.

The “Houston cocktail”: This is the nickname for a combination of a prescription opioid, carisoprodol (a muscle relaxant brand-named Soma) and alprazolam (brand-named Xanax). This combination is reputed to give a high similar to that of heroin. An analysis of drivers who tested positive for this combination found that they had slurred speech, poor balance and problems managing lane position, speed and braking.

Marijuana and PCP or formaldehyde: These drugs are usually consumed as a marijuana cigarette (joint) that’s been dipped in or laced with PCP (phencyclidine) or formaldehyde. The combination can result in respiratory failure and death. This type of joint is referred to as smoking “wet” or “fry.”

Polydrug Use Among Clubbers

Club girl, polydrug effects

Polydrug use is extremely common among those going to nightclubs and dance clubs. One study that focused on these individuals found that 92% of the clubbers surveyed engaged in polydrug use. These 367 people reported 1,670 different combinations of drugs with ecstasy (MDMA) the most commonly combined drug.

The combinations named included:

  • Ecstasy and ketamine
  • Ecstasy and cocaine
  • Ecstasy and GHB
  • Ecstasy and marijuana
  • LSD and marijuana
  • Cocaine and alcohol

While the exact dangers of combining drugs depend on the combination, one study of those combining club drugs found that these effects were common:

  • Addiction
  • Fatal or non-fatal overdose
  • Reduced cognitive function
  • Psychiatric problems
  • Impaired learning
  • Inability to feel pleasure
  • Depression

In particular, those who use ketamine are particularly likely to mix the drug with other substances. A study of New York City ketamine injectors found that they were likely to mix it with marijuana, alcohol, heroin, speed, ecstasy or hallucinogens.

How Common is Polydrug Abuse?

During 2017 and 2018, the CDC states, more than 37% of overdoses treated in emergency rooms involved more than one drug. Another report from the CDC noted that of those who died in 2016 from synthetic opioid overdose (almost always fentanyl), nearly 80% of these individuals had consumed another drug such as another opioid, heroin, alcohol, a benzodiazepine or cocaine. Polysubstance Overdose Deaths Are Increasing

Drug overdose rescue

According to the Centers for Disease Control and Prevention, the following combinations are increasingly common among overdose cases:

  • Opioids, cocaine, and amphetamines
  • Opioids and amphetamines
  • Opioids, cocaine, amphetamine, and benzodiazepines

An extensive study from North Carolina found that 53% of opioid overdose deaths involved multiple substances. The most common combinations in this study were:

  • Opioids and stimulants
  • Opioids and benzodiazepines
  • Opioids and alcohol

An Urgent Need for Rehab

This article is only a quick overview of this subject. A complete listing of all the combinations and their harmful effects would fill a small book. This information should be sufficient to communicate the idea that polydrug use is widespread and extremely harmful to the drug user. At any moment, a combination of stimulants could blow out his (or her) cardiovascular system. Nervous system depressants could gang up and stop the person’s breathing or heart.

When combining drugs becomes acceptable to a person as they chase a particular high or try to alleviate undesirable effects of a particular drug, they enter a whole new realm of drug abuse. They medicate themselves up, down, or out of touch completely. They create an utterly synthetic world for themselves or turn off every perception. Ideas of safety and protecting their health are long gone.

Of all the drug users in the world, a person who is a dedicated polydrug user might be the most endangered and the one most in need of immediate drug rehab. But it’s hard to tell them that. It could take considerable effort to overcome the allure that drugs have for them and the synthetic, chemical world they have created for themselves.


Reviewed by Claire Pinelli, ICAADC, CCS, LADC, RAS, MCAP, LCDC


Karen Hadley

For more than a decade, Karen has been researching and writing about drug trafficking, drug abuse, addiction and recovery. She has also studied and written about policy issues related to drug treatment.