Zolpidem is a sedative from the imidazopyridine class of drugs that is most commonly used to help people fall asleep faster. But, in rare cases, this common drug can actually restore function to damaged brains.

There is a reason why zolpidem is sometimes referred to as the “Lazarus Drug”. If you give this pill to someone with brain damage, in 5% to 6% of cases something miraculous happens. In most cases, the changes are minor. People’s speech improves slightly, the frequency of muscle spasms is reduced, they have less difficulty moving, but in some rare cases, a pill can even bring people back from vegetative states, allowing them speak and move as they did before suffering brain damage. The problem is that these positive effects are gone as soon as the drug wears off, and scientists have yet to discover why some patients with brain damage react this way to zolpidem.

Researchers from Radboud University Medical Center and Amsterdam University Medical Center recently reported the case of a 37-year-old man named Richard who had been left with severe brain damage after experiencing a severe lack of oxygen, eight years ago. Richard was no longer able to talk, eat independently, or move by himself. He was diagnosed with akinetic mutism and was admitted to a specialized nursing home. It was here that Willemijn van Erp, an elderly care physician and researcher at Radboud University Medical Center, met Richard.

“It was clear that Richard saw and heard us, but because of his brain injury, he was barely able to respond to us.” van Erp wrote in an article published in the Cortex medical journal.

Richard had been barely responsive in the eight years since hypoxia had left him with akinetic mutism, and at this point his family was willing to try anything to improve his condition. Willemijn van Erp knew of a sleeping medicine that could sometimes have remarkable effects on patients suffering from brain disease, and after talking it over with Richard’s family, they decided to administer him a Zolpidem pill.

“Against all expectations, Zolpidem had remarkable effects,” van Erp wrote. “After taking the sleep pill, Richard started talking, wanted to call his father, and started recognizing his brothers again. With some help, he could even get up from his wheelchair and walk short distances.”

This all happened in only 20 minutes, from a single 10-miligram Zolpidem dose, and brain scans taken during this period illustrated the drug’s miraculous effects.

“If you could compare the function of the brain, as it were, to a large string orchestra, in our patient the first violins play so loud that they drown out the other members of the string orchestra and people can no longer hear each other. Zolpidem ensures that these first violins play more ‘pianissimo,’ so that everyone plays back within time,” Dr. Hisse Arnts, a neurosurgical resident at Amsterdam UMC, said.

Unfortunately, Zolpidem’s positive effects have a limited duration and in Richard’s case, they started wearing off after about two hours. His dosage was quickly increased to three doses per day, but the positive effects started to subside with increased use after several days. Research has shown that if the dose is too high, the beneficial effects are replaced by the drug’s action as a sleeping pill.

In the scientific community there are several theories on how Zolpidem actually works on some brain-damaged patients, but sadly none of these hypotheses is perfect. For the time-being, the phenomenon caused by the Lazarus Drug remains a mystery, but it remains a glimmer of hope for people hoping to bring their loved-ones from comas or vegetative states.