Fentanyl and Amnesia: Yet Another Dangerous Result of Addiction

A man struggles with loss of his memory.

Being addicted to an opioid is bad enough. Every time the drug is used, there’s a risk of overdose. And if more of the drug can’t be obtained in time, withdrawal sickness will kick in. It’s a rough life that, in their hearts, those who are addicted would love to leave behind forever. But now there’s a new threat lurking in the shadows: The possibility that the drug user will suffer amnesia if they consume the synthetic opioid fentanyl. And for some, this condition could last for months.

According to a report in the New England Journal of Medicine, 14 patients in Massachusetts received medical care for amnesia between 2012 and 2016. Thirteen of these patients had a history of opioid use or tested positive for opioids. They were not specifically tested for fentanyl because doctors had not yet zeroed in on this intensely-powerful drug as a possible cause of their amnesia.

Up to this time, the fentanyl being abused was being stolen or otherwise diverted from medical facilities. But then, criminal pharmaceutical companies overseas realized the potential for vast profits and began to manufacture fentanyl and traffic it into the United States. Fentanyl found its way into heroin supplies in the U.S., and it was shaped into pills or simply sold as fentanyl itself. A person going out to buy heroin could easily wind up with fentanyl and not know it.

Fentanyl in brick and counterfeit pill forms.
Illicit fentanyl pressed into a brick and formed into counterfeit prescription drugs. Photos courtesy of the Drug Enforcement Administration.

By 2017, law enforcement and medical personnel were very familiar with the problems being created by fentanyl. So when 4 more patients showed up in Massachusetts hospitals suffering from amnesia, they were tested for fentanyl. All of them tested positive. Two of these 4 patients had no other drugs in their bodies.

The doctors reporting on this phenomenon commented on the increasing presence of fentanyl in the illicit drug supplies and note that the ability of the drug to shut down blood flow and oxygen supply to the brain could be the cause of the amnesia.

It’s very easy to overdose on fentanyl because it is so powerful. While these individuals survived their use of this drug, just a little too much of it could have slowed their breathing to the point that their brains did not receive the oxygen they needed to function normally. The doctors concluded that this deprivation could be the cause of the amnesia.

What Is Anterograde Amnesia?

Anterograde Amnesia the particular kind of amnesia suffered by these patients. They didn’t lose all their memories, but they could not form new memories for any events after the incident that caused the amnesia—in this case, the use and non-fatal overdose of fentanyl.

In another case of amnesia in West Virginia, a man’s family found him asleep, surrounded by drug paraphernalia. They tried to wake him up and when they finally succeeded, he kept asking the same questions over and over. A brain scan found irregularities in the hippocampus, a part of the brain associated with memory. Brain scans on other patients suffering from this problem have also found irregularities of the hippocampus.

When this man was finally tested for drugs 80 hours later, only norfentanyl was found. When fentanyl is broken down by the body, one of the substances created as a result is norfentanyl.

In some cases, the amnesia lasted for months. One patient continued to suffer from amnesia after five months and it took two other patients more than a year to recover.

If anyone needed another reason to get help for addition, this new threat provides it.


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.