A new implant tested on animals reverses drug overdoses

Naloxone has saved thousands of lives by reversing opioid overdoses. But its success depends on having someone nearby who can administer the medicine quickly (SN: 03/05/24). Many people are alone when they overdose.

A new implant could someday solve this problem. Inserted under the skin and powered by a battery, the device can detect the onset of an overdose and release naloxone directly into the bloodstream while alerting first responders, researchers reported Oct. 23 in Science Advances. The device, called Naloximeter, was only tested on animals.

Researchers hope the Naloximeter can help some of the most at-risk individuals: those who are newly sober, whether because they sought treatment or were incarcerated. People are 10 to 16 times more likely to die from an overdose in the first few months after a period of sobriety, when their body’s tolerance to opioids has decreased, than when they are in recovery.

As of 2023, more than 80,000 people in the United States have died from opioid overdoses (SN: 09/25/2024). “This fentanyl problem is getting worse,” says Robert Gereau, a neuroscientist at Washington University School of Medicine in St. Louis. “There is a huge need for as many harm reduction efforts as possible.”

Common harm reduction techniques include safe injection centers and hotlines, but new technologies offer promising alternatives for when a bystander cannot be present (SN: 02/14/2024). So far, apps and other devices can only monitor and alert responders. The Naloximeter is the first device that can provide treatment – ​​and do so immediately, in the narrow window when overdoses are still reversible. “That’s where this really stands out compared to other interventions,” says Monty Ghosh, an addiction researcher at the University of Alberta in Edmonton, Canada, who was not involved in the study.

The Naloximeter sensor works by measuring oxygen loss in the blood – specifically, how quickly it is falling and at what level. In a human version of this implant, once an overdose is detected, a warning alert would appear on the person’s cell phone so they can indicate whether it is a false alarm; otherwise, naloxone would be released.

Gereau and colleagues tested two different administration methods in rats and pigs. In tests with pigs, they found that the most effective method was an intravenous catheter, similar to a port used for cancer treatment, integrated into the implant. It released 0.7 milliliters of naloxone in 60 seconds, which is “enough to start having a lot of effect in the brain,” says Joanna Ciatti, a materials scientist at Northwestern University in Evanston, Illinois.

Although it is still a long way from being tested in human clinical trials and resolving ethical and logistical issues, the prospect of such a device is exciting, says Ghosh. Its feasibility will depend on the invasive nature of the implant, its cost and, most importantly, whether people with concerns about substance abuse, often wary of interventions, will be open to it.