In 2023, more than 80,000 people in the United States died of opioid overdoses. An overdose occurs when a person takes too much of an opioid (morphine, heroin, fentanyl, etc.) or a combination of drugs that is at a level that is toxic to the body. It can be difficult for bystanders to determine whether the person using opioids is just high or actually experiencing a life-threatening overdose. Fortunately, naloxone, an opioid antagonist medication that rapidly reverses opioid overdoses, has saved thousands of lives since it was first approved as an over-the-counter (OTC) nasal spray by the FDA in March 2023. There is just one problem: the success of the drug is dependent on someone being nearby who can administer the drug quickly. Oftentimes, people overdose when alone.
“This fentanyl problem is getting worse,” says Robert Gereau, a neuroscientist at Washington University School of Medicine in St. Louis. “There’s a huge need for as many efforts at harm reduction as possible.”
On October 23, researchers reported a new implant could someday be the solution in Science Advances. Naloximeter, a device that can be inserted under the skin and run by a batter, can detect an overdose’s onset and release naloxone directly into the bloodstream, even when a person is alone. Simultaneously, it can alert first responders. So far, Naloximeter has only been tested on animals, but researchers hope that the device could eventually help high-risk individuals. For example, those who have just begun their sobriety journey are 10 to 16 times more likely to die from an overdose in the first several months since their bodies’ tolerance to opioids has only just decreased.
The Naloximeter’s sensor works by measuring the amount of oxygen loss in the blood, and how quickly the oxygen level is dropping. For the human version of the implants, once an overdose is detected, the device will send a warning alert to the individual’s cell phone so the person can identify if it is a false alarm. If not, the naloxone would be released into the bloodstream.
Gereau and his colleagues tested two different administration methods in rats and pigs. They implanted the device into the neck, chest, or back of various animals to determine the best placement for the implant. It was found that the device detected overdose within a minute of dropping oxygen levels, and all animals fully recovered within five minutes of receiving naloxone from the device. In the pig trial, it was determined that the most effective method for administering naloxone was an intravenous catheter integrated into the implant, something similar to a port used for cancer treatment. Within 60 seconds, the device would deliver 0.7 milliliters of naloxone, enough to start having an effect on the brain.
Though the Naloximeter still has a long way to go before it can be used on humans, the prospect of this type of life-saving device is promising. The Naloximeter is the first device to provide such immediate treatment during the timeframe when overdoses are still reversible.
“That’s where this really excels in comparison to other interventions,” says Monty Ghosh, an addiction researcher at the University of Alberta in Edmonton, Canada.
“The Naloximeter is a proof-of-concept platform that isn’t limited to the opioid crisis,” said Joanna Ciatti, a graduate student in Rogers’ lab. “This technology has far-reaching implications for those threatened by other emergent medical conditions such as anaphylaxis or epilepsy. Our study lays important groundwork for future clinical translation. We hope others in the field can build off of these findings to help make autonomous rescue devices a reality.”
