doctor talking to a young woman patient

Recognizing the warning signs of an opioid overdose can save a life. A person in this scenario may be unconscious with very small pupils and slow or shallow breathing. They may also be unable to speak and have a faint heartbeat and cold, clammy skin. Their lips and fingernails may look blue or purple.

Overdose is a medical emergency, and fast medical attention can be lifesaving using the highly effective rescue medication naloxone, an opioid blocker. Many states have passed “Good Samaritan” laws that legally protect a person who experiences an overdose, as well as those who call 911 to report the emergency and help the individual.

But because, tragically, most people overdose alone, other solutions are necessary. One currently in development is an implanted device that will automatically detect an overdose and give naloxone. This work is funded by the Helping to End Addiction Long-term® Initiative, or NIH HEAL Initiative®, which is looking for new treatments for opioid use disorder and overdose.

Technology Solutions

The majority of overdoses now involve strong synthetic opioids like fentanyl that work in very small amounts. People who use drugs often do not know exactly what they are taking, and if substances are injected, they take effect very rapidly. Among the most vulnerable to overdose are those who have not used drugs in a while, such as people in recovery or those being released from jails or prisons.

High doses of opioids like heroin or fentanyl can have dangerous side effects because they stick to cells in the part of the brain that controls breathing. Naloxone reverses an opioid overdose by displacing these opioid molecules. Currently, naloxone can be given by injection or through a prefilled, needle-free nasal spray that requires no assembly and is available at pharmacies. Law enforcement and first responders often carry it with them.

A HEAL-funded research team is taking a creative approach that might be able to help individuals experiencing an overdose when no one else is around.

Robert Gereau, Ph.D., of Washington University in St. Louis, Missouri, and John Rogers, Ph.D., of Northwestern University in Evanston, Illinois, are developing a miniaturized overdose-detection device. Implanted under the skin, the device would detect an overdose, automatically administer naloxone, and alert emergency responders and other members of the individual’s support system.

The implant technology works by continuously measuring blood oxygen levels and automatically administering naloxone when oxygen levels get dangerously low, which occurs during an overdose. Although measuring blood oxygen is a common medical procedure – for example, using small devices called oximeters that clip to an individual’s finger or earlobe –  these wearable devices are conspicuous and impractical for long-term use in people with opioid use disorder.

If this now-experimental device is approved for use in humans, it will be able to do several things. In addition to measuring blood oxygen levels, the device has a rechargeable battery to power it and a pump with multiple reservoirs of naloxone as a backup in case the first dose isn’t delivered correctly or is not enough.

To be optimally effective, the device will be able to operate independently and communicate if and when a person can’t. The HEAL-funded team is developing a chip connected to a mobile device that can alert emergency responders or others who can help.

So far, this experimental naloxone implant works well in rodents, and researchers will next test it in larger animals, such as pigs, whose body functions more closely resemble those of the human body. Those tests will help determine, for example, the best place in the body to implant such a device and measure oxygen levels.

Other Options

Although technology-based solutions like this naloxone implant will increase the number of tools to keep people healthy and save lives, other options to expand awareness and use of medications like naloxone are being explored.

For example, HEAL-funded research is working on increasing use of naloxone by teaming with communities to reduce stigma about its use. Other strategies include different versions of opioid blockers, novel molecules that work outside the body’s opioid system, and even wearable devices being developed to detect problems with breathing that often precede overdose.

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