The number of deaths linked to opioid painkillers has risen dramatically over the past two decades. But tens of millions of Americans still suffer from serious pain and stand to benefit from these drugs. How do policymakers balance those conflicting forces as they consider more restrictions on opioids?

It's a question public health experts and lawmakers have been struggling with over the past few years as opioid deaths have risen. In late April at Stanford University, two experts — pain medicine expert Sean Mackey and addiction expert Anna Lembke — held a debate on the issue, giving a nice rundown of where both sides stand.

The debate essentially comes down to which side one sympathizes with the most. Are you more worried about the 100 million or so Americans who reportedly suffer from chronic pain, or are you more concerned with the public health crisis that's been born out of opioid abuse, killing tens of thousands each year? As they consider more restrictions on painkillers, policymakers and public health experts have to balance out these needs. But to do that, people have to know the full scope of the arguments from both sides, which the Stanford debate neatly presents.

The case for prescription painkillers

Approximately 100 million US adults suffer from chronic pain, according to a 2011 report from the Institute of Medicine. This might seem like an excessive number — roughly one-third of all Americans — but it includes everyone in the chronic pain spectrum, from the silent sufferer who deals with constant back pain to the patient who can no longer move because the pain all over her body is just too much.

This is the primary concern for Mackey, who argues that prescription painkillers shouldn't be restricted too much. He said painkillers can be a crucial tool for treating people's short-term pain, and, in some cases, they also might make sense for some patients to use for chronic pain. (On the other hand, Mackey acknowledged, the established long-term harms can far outweigh the established long-term benefits, as one review of the evidence published in the Annals of Internal Medicine concluded.)

"what [patients] want is control of their lives back"

But Mackey explained that painkillers should only be used as part of a broader treatment program, referencing the team he's built at his own pain treatment clinic. "We all come together in a team-based environment, with pain medicine physicians across all walks of training — anesthesiologists, PM&R neurology, psychology, internal medicine," he said. "We've built it with pain psychology, with physical therapy, with dietary, with biofeedback. And we do it in a co-located, coordinated model."

Still, if society stigmatizes opioid painkillers too much, Mackey worries there's a risk of pushing doctors away from ever using prescription painkillers. That would be devastating for many patients who genuinely benefit from the drugs.

"[My patients] are not saying, 'Hey, can you take away all my pain? I can't handle any pain,'" Mackey said. "For the most part, what they want is control of their lives back. They want to be able to get back to doing the things they were doing that they can no longer do because pain has robbed them of that."

The case against prescription painkillers

As opioid-linked deaths rise, some public health experts and officials, including Lembke, have called for more restrictions on the drugs and restraint from the people prescribing them.

The annual number of opioid painkiller prescriptions is now at more than 200 million. In hand with that, overdose deaths have shot up from over 4,000 in 1999 to more than 16,000 in 2013, according to data provided by the Centers for Disease Control and Prevention.

Many of these overdoses are linked to other drugs. The CDC found that 31 percent of prescription painkiller-linked overdose deaths in 2011 were also linked to benzodiazepines, a legal anti-anxiety drug. Alcohol and muscle relaxants can also increase the risk.

Prescription painkiller addiction can also lead to the use of other opioids, like heroin. A 2014 study published in JAMA Psychiatry found, "Although the 'high' produced by heroin was described as a significant factor in its selection, it was often used because it was more readily accessible and much less expensive than prescription opioids." And a 2015 CDC analysis found people who are addicted to prescription painkillers are 40 times more likely to be addicted to heroin. That's part of the reason deaths from prescription painkillers and heroin have both generally trended up over the past couple decades.

There are risks to opioids besides overdose and addiction, too. Lembke listed several other side effects experienced by opioid painkiller patients: endocrine abnormalities, lower testosterone, pain in areas they didn't have pain before (known as opioid-induced hyperalgesia), increased cardiac risk, higher fracture risk, and severe, debilitating constipation.

"there are no strong data to support the use of opioids for chronic pain"

There's also scant data that painkillers can treat long-term, chronic pain. They can be very good at treating short-term, acute pain, but the research has found little evidence to support their use for long-term issues. "It's currently important to emphasize that there are no strong data to support the use of opioids for chronic pain," Lembke said. "The reason it's really important for the public to understand that is because in the 1980s and 1990s a different message was communicated to health-care providers."

So how should doctors deal with this? Lembke argued they should be more reluctant to prescribe painkillers, especially to people who seem to have a long history of abuse. Instead, patients should be guided through alternatives, like self-management of pain in which they set realistic goals to cope with chronic pain without resorting to potentially dangerous drugs.

Mackey and Lembke also agreed that doctors should get more training on pain and addiction treatment.

"The average medical student gets seven hours of pain medicine education in this country. Vets, by the way, get 40 hours of pain," Mackey said, "which is great if you've got a dog in pain, not so good if you've got a loved one."

Lembke countered, "And that's seven more hours and 40 more hours than they get for addiction treatment."

Drug policy is all about balance

Drug policy is hard. There's no perfect solution to the conflict between treating pain and curtailing the abuse of opioid painkillers. Really smart people have been arguing where the balance lies, as the debate in Stanford shows.

"There's always choices," Keith Humphreys, a drug policy expert at Stanford University, previously told me. "There is no framework available in which there's not harm somehow. We've got freedom, pleasure, health, crime, and public safety. You can push on one and two of those — maybe even three with different drugs — but you can't get rid of all of them. You have to pay the piper somewhere."

Policymakers have already seen this with the crackdown on opioid painkillers. As law enforcement has come down on doctors believed to be over-prescribing painkillers, some addicts have been turning to heroin, leading to a spike in heroin deaths. And there have been several reports of doctors denying pain patients painkillers simply because they're afraid of looking to law enforcement like they're overprescribing the drugs.

"There is no framework available in which there's not harm somehow"

There are some fixes that both Mackey and Lembke agreed on, though. Both brought up that there are alternatives to opioids, including psychological treatments that help cope with pain and even different forms of exercise, such as yoga. And doctors should be able to prescribe medicines that help addicts cope with painkiller addiction without going through severe withdrawal, like Suboxone and methadone.

But Lembke pointed out that policies often make it difficult to seek these options. Sometimes insurance companies don't cover them. Sometimes addiction medicines, such as Suboxone, have much more restrictive prescription requirements than painkillers do. All of this makes it much easier (and affordable) for physicians to prescribe painkillers without going to alternatives or potential medicines to cope with addiction.

"If I want to write a prescription for oxycodone, I have absolutely no trouble getting the insurance company to pay for it and the pharmacy affiliate," Lembke said. "If I want to write a prescription for Suboxone to treat an opioid addiction, I get about four pages of paperwork and about — literally — three hours on the phone arguing for why that patient needs that drug."

Mark Kleiman, a drug policy expert at New York University's Marron Institute, said in an email that doctors could also do a better job communicating the risks of opioids to patients, particularly the deadly effects of mixing them with other drugs like alcohol.

There's also a potential drug alternative to opioid painkillers: medical marijuana. One study published in the Journal of the American Medical Association found that states that allow pot for medicinal purposes have fewer prescription painkiller deaths than one would otherwise expect. Intuitively, this makes sense: marijuana is a potent painkiller for some types of pain, so it can potentially substitute for deadlier and more addictive opioids in some cases. But experts caution this field of research needs more study to see how much of the relationship between medical pot and prescription painkillers is causation and not just correlation.

But all of this comes down to a balancing act for policymakers and doctors. Patients need help with their chronic pain, but the widely used medicine for pain is abused and downright dangerous in many situations. Finding the right balance is going to continue to present a major challenge for public health experts in the next few months and years.