Science

Kyoto University Researchers Develops Highly Effective Non-Addictive Pain Reliever

Yomiuri Shimbun file photo
Kyoto University in Sakyo Ward, Kyoto

The Yomiuri Shimbun

20:00 JST, August 10, 2025

A team of Kyoto University researchers has announced that they have found a powerful painkiller candidate that can alleviate the severe pain of cancer patients without major negative side effects.

Currently, fentanyl is used for this purpose, but its intensely addictive nature poses major issues. The researchers said the new drug is non-addictive, and they aim to put it into practical use as early as 2028.

Pain relievers are divided into two categories: non-opioids, such as aspirin, which are used for mild pains, and opioids, such as fentanyl and morphine, which have incredibly stronger.

However, opioids cause side effects such as trouble breathing and addiction issues. In the United States, there have been many people who have unlawfully obtained and abused opioids, with more than 80,000 overdose deaths involving opioids in 2023.

Kyoto University Prof. Masatoshi Hagiwara and Associate. Prof. Masayasu Toyomoto focused on noradrenaline, a neurotransmitter that suppresses pain. They found a compound in a database that increases the secretion of noradrenaline and named it “Adriana.” When this compound was administered to mice and monkeys, it was found to have pain-relieving effects comparable to those of opioids, without causing respiratory distress or dependence.

In addition, a clinical trial was conducted at Kyoto University Hospital involving 20 patients who had undergone lung cancer surgery, yielding promising results. Hagiwara said, “If this compound is put into practical use, it can largely contribute to the reduction of opioid use in medical settings.” The team is scheduled to conduct a clinical trial involving hundreds of participants in the United States as early as next year.

“If the pain reliever demonstrates efficacy in treating chronic pain that is difficult to treat, it has the potential for widespread use,” said Makoto Tsuda, a professor at Kyushu University and a neuropharmacology expert.