New Painkiller Developed by Kyoto University Researchers Offers Non-Addictive Alternative to Opioids

Researchers from Kyoto University have unveiled a new tablet painkiller called Endopin, which offers a safer alternative for pain relief compared to well-known medications like fentanyl. They assert that this new drug can effectively treat acute pain, particularly for cancer patients, without the addictive characteristics and detrimental side effects normally linked to opioid medications.

The development team emphasized that Endopin allows patients to experience pain relief without the severe complications often seen with opioids, such as drowsiness or altered consciousness, which is conducive to a better overall quality of life. Professor Masatoshi Hagiwara highlighted the commitment of the research team to pioneer alternatives for patients suffering from tumors and other severe pain conditions.

A start-up involved in drug development is gearing up to initiate Phase II clinical trials in the U.S. to further validate Endopin's effectiveness among patients. Opioids, like morphine, have historically been relied upon in medical situations, but their propensity for addiction has led to a public health crisis in North America, causing tens of thousands of overdose deaths each year.

In response to this ongoing crisis, scientists have actively sought substitutes offering similar pain-relieving capabilities without the risks of addiction or serious adverse effects. The Kyoto team focused on understanding the unique mechanisms through which noradrenaline—a neurotransmitter—acts to dull pain during critical health events. They identified a specific chemical that can obstruct the controlling pathway for noradrenaline secretion, allowing for a sustained release that mitigates pain.

Experimental results indicated that Endopin matched morphine in efficacy on mice with post-surgical pain or those diagnosed with osteosarcoma, but without triggering anxiety or depressive behaviors. Additional tests conducted on a small group of patients recovering from lung cancer surgery at Kyoto University Hospital also reported significant pain reduction. The comprehensive findings of this research were published in the Proceedings of the National Academy of Sciences of the United States of America on August 7.