Pain relievers are diverse. By interacting with different parts of the nervous system, they treat some pains better than others. Shane Kaski is investigating whether an anti-itch medication that targets a specific part of our nerve cells can make morphine — which targets a different part — more effective. His findings suggest it can.
If he’s right, doctors may be able to prescribe lower doses of morphine by supplementing it with the drug, called nalfurafine, and still soothe their patients’ pain.
Morphine is a classic, widely-used opioid. Using less of it could mean fewer morphine-related side effects — such as constipation and nausea — and a lower risk of addiction.
“Right now there’s a lot of work looking for replacements for opioids, for obvious reasons,” said Kaski, a graduate student in the School of Medicine’s M.D./PhD program. “Maybe nalfurafine is not so great as a replacement on its own, but maybe it does enough that we could put it together with other opioids and get this dose-sparing effect.”
In his study, funded by the National Institute of Drug Abuse, Kaski used animal models to test how well morphine treated pain on its own and in combination with nalfurafine. He discovered that using a small supplement of the anti-addictive nalfurafine alongside a lower dose of morphine reduced pain as dramatically as using a large dose of morphine alone.
“It’s possible that you just need a tiny smidgen of nalfurafine with a smidgen of this other drug to get the equivalent pain relief from a larger dose of your addictive drug,” he said. “That’s what we’re seeing in our early work. That’s the promise that we saw.”