Health Experts Sound the Alarm Over Allergy Meds Found in Street Opioids

Confused paramedics

The discovery of allergy meds mixed into illicit opioid drugs is yet another example of how users can never be 100% certain of what is in their drug. That is why drug addicts must understand how every instance of drug use could create a fatal result, highlighting the importance of addicts seeking treatment and getting off of drugs as soon as possible.

The Story

Every week, the Centers for Disease Control and Prevention publishes a detailed report outlining newsworthy health risks that Americans should know about. In October 2022, one of their reports raised the alarm about a growing trend of drug dealers mixing over-the-counter allergy medications into batches of opioid drugs.

Lab test

According to the reporting, diphenhydramine is the prime drug in question, a common over-the-counter (OTC) allergy medicine found in brand-name drugs like Benadryl. Opioid use can produce itchy skin as a side effect in some users, so drug dealers began mixing OTC allergy meds into their opioid supply. However, drug dealers found that adding allergy meds to opioids made the opioid high last longer for some users, and unfortunately, it also made the opioid high more dangerous.

The sedating effect of diphenhydramine makes the overdose reversal medication naloxone less effective. Further, it makes the opioid/diphenhydramine hybrid drug more potent. The result is a more potent synthetic opioid that produces a longer-lasting high, is more dangerous, and is more likely to create an overdose that emergency naloxone medication cannot reverse.

“Nearly 15% of overdose deaths during 2019-2020
were antihistamine-positive...”

Unfortunately, this new trend of mixing street opioids with diphenhydramine is spreading rapidly across the United States. According to Amanda Dinwiddie, a representative of the CDC’s Division of Overdose Prevention at the National Center for Injury Prevention and Control, “Nearly 15% of overdose deaths during 2019-2020 were antihistamine-positive, [and] a death was defined as antihistamine-positive if any antihistamine was detected on postmortem toxicology or was listed as a cause of death on the death certificate. Most antihistamine-positive and antihistamine-involved deaths included diphenhydramine, which is easily accessible over the counter as an allergy medication and sleep aid.”

The CDC report noted that, of the more than 92,000 drug overdoses recorded during the study period, at least 13,500 deaths included some antihistamine medication. Further, at least 3,345 of those overdoses listed antihistamines as a partial cause of the victim’s death, suggesting the once unusual, relatively rare trend of mixing allergy meds into a supply of opioids is now becoming a common practice among dealers and traffickers.

Increased Risk to Addicts

Two factors make the situation of antihistamines being mixed into opioids all the more dangerous for addicts:

First, the increased potency created by the mixture and the resulting long, drawn-out drug high act as an incentive for addicts to seek out the new hybrid drug, even though addicts are more likely to overdose on it.

Second, the fact that naloxone does not seem as effective against opioid overdoses that involve histamines makes it more likely addicts will die from overdosing on the drug. It makes it more likely emergency responders or nearby friends or family members won’t be able to save the addict from an overdose.

With recent reports indicating drug overdose deaths have topped 100,000 fatalities annually, it is no mystery that the United States is suffering the most lethal drug addiction crisis in recorded history. Any new trend that makes drug use even more dangerous should act as a major incentive for the family members and loved ones of addicts to take action.

Qualified Addiction Treatment is Available

Any form of drug use is dangerous, and there is no denying drug use is becoming more life-threatening each year. Thankfully, qualified drug rehab centers are available to provide life-saving care to struggling addicts, to empower them with the tools they need to live life without drugs. If you have a family member or loved one who uses drugs and cannot stop, please help them enter a residential rehab program today. Please don’t wait until it is too late.


  • CDC. “Morbidity and Mortality Weekly Report.” Centers for Disease Control and Prevention, 2022.
  • USNews. “Allergy Meds in Street Opioids Make Overdoses More Deadly.” U.S. News, 2022.
  • CDC. “Drug Overdose Deaths in the U.S. Top 100,000 Annually.” Centers for Disease Control and Prevention, 2021.



After working in addiction treatment for several years, Ren now travels the country, studying drug trends and writing about addiction in our society. Ren is focused on using his skill as an author and counselor to promote recovery and effective solutions to the drug crisis. Connect with Ren on LinkedIn.