美国国家公共电台 NPR Brain Scientists Look Beyond Opioids To Conquer Pain（在线收听）

DAVID GREENE, HOST:

This question of how to find that balance when you have patients in pain and doctors who are fearing addiction is coming up this week as the Society for Neuroscience holds its meetings here in Washington, D.C. And NPR's Jon Hamilton has been attending. And he's with us in the studio. Hi, Jon.

JON HAMILTON, BYLINE: Hi.

GREENE: So is this the future we're looking at, people who are in chronic pain - like we just heard - having to struggle to get treatment because of these legitimate fears about addiction?

HAMILTON: It's the future that doctors and scientists are trying to avoid. But here's the problem - in the U.S. right now you've got, like, 2 million people who are abusing opioids. At the same time, you've got more than 50 million people - some estimates say 100 million - who are in chronic pain. So how do you balance trying to curb drug addiction while you're still looking out for people who are in pain?

And I should say, doctors have faced this dilemma before. Back in the 1980s, there was the war on drugs, there was the Nancy Reagan Just Say No campaign, and back then, the concern was largely illicit drugs. But it had an effect on doctors, and many of them became really reluctant to prescribe addictive drugs. And there were cases where cancer patients could not get drugs to relieve their pain.

GREENE: So a lot of neuroscientists here in Washington, D.C., this week - who you'll be spending time with - are you learning anything from them?

HAMILTON: Yes, I already have learned a few things from them. Later today, of course, there's going to be a panel of scientists who are talking about precisely this topic - addiction and opioids and pain. And one of the things researchers have learned is how many different brain circuits there are involved in both addiction and pain.

You know, for example, there's now a whole lot of research showing how the brain actually creates what they would call our perception of pain. So for instance, when you stub your toe, there's a signal that goes up into your brain. But that signal - the strength of that signal - is affected by all these things - attention, emotion, your mood. And so if, like, you're at the dentist and you're expecting to feel pain, you will feel more pain. If you're depressed, you are likely to feel more pain. If you're distracted, you may feel less pain.

GREENE: So many factors.

HAMILTON: So many factors.

GREENE: Well, is there a way to use that knowledge and this reality that there are so many factors to come up with better medication for pain that maybe avoids the addiction we see in opioids?

HAMILTON: That is the hope. I was talking to a scientist named Ed Bilsky. He's from Pacific Northwest University. He's the guy who's going to be moderating the panel later today on opioids and pain. And he told me the problem with opioids is that they are this really blunt instrument for treating pain. So at the same time they're hitting these circuits that are involved in pain, they're also hitting these circuits that are involved in reward and pleasure and all the things that are related to addiction. So the idea is to come up with drugs that are much more specific.

And there are a few candidates out there, actually. One of the most interesting ones I've been hearing about is made from the venom of a type of snail.

GREENE: Huh.

HAMILTON: And what's great about it is it targets totally different receptors in the body than opioids do, and yet it appears to be much more powerful as a pain reliever. So there is reason for hope.

GREENE: NPR's Jon Hamilton. Thanks, Jon.

HAMILTON: You're welcome.