A box of the opioid antidote naloxone is on display during a family-addiction support group event in 2016 in Groton, Conn. (John Moore/Getty Images)

Amid broad efforts to help people avoid prescription-opioid addiction, some pharmaceutical companies are taking an intriguing approach: making prescription opioids that can’t be misused. Although the tactic may at first blush seem a miracle cure, it has a decidedly mixed record of success.

Pharmaceutical companies have several methods of designing abuse-deterrent opioids. Some of the protections are physical, making the drugs more difficult to grind into a powder that can be snorted or made into a liquid that can be injected. Others are chemical: The opioid buprenorphine is sometimes combined in a tablet with another drug known as naloxone. If the pill is crushed, the opioid is rendered inert by the naloxone and no longer causes a high.

Here's how the drug naloxone can stop opioid overdoses. "You can actually resurrect someone," said Dr. Phil Skolnick from the National Institute on Drug Abuse. (NIDA/NIH)

In 2010, Purdue Pharma reformulated OxyContin after facing widespread condemnation for how this opioid was being abused. The new formulation makes the pill chunky and somewhat goopy when crushed, diminishing its utility as a recreational drug. The change seems to have been partly successful, as it was followed by reduced (though not eliminated) OxyContin-caused emergency-room visits and admissions to substance-use-disorder-treatment facilities.

Other companies have had the strategy backfire with deadly consequences. In 2012, Endo Pharmaceuticals reformulated extended-release Opana to make this potent opioid harder to crush and inhale, but some users responded by developing a method to inject it instead. Injecting opioids is dangerous in itself, and becomes even more so when users share needles, as this can generate HIV outbreaks such as occurred in Scott County, Ind., in 2015. Extended release Opana’s role in fueling that public health tragedy was a factor in the FDA’s recent request to have Endo removed from the market.

Companies that create a harder-to-abuse version of their drugs also typically sell fewer of their drugs, a positive for public health but a hit to their bottom line. The new, abuse-resistant drugs are often more expensive than older models, as well as less in demand from patients. As long as abuse-deterrent formulations are not mandatory for all opioids, a company that invests in the technology is likely to forfeit market share to its competitors. Financial incentives thus punish rather reward companies for trying to reduce abuse of their opioids.

However, even if every single opioid available had abuse-deterrent features, people could still become addicted to them even while following their prescriptions to the letter. Also, even if an opioid could no longer be used in liquid or powder form, it would still be possible for addicted users to get their desired fix by taking larger-than-prescribed doses orally. Abuse-resistant technology thus  adds a new hurdle, but it hardly rules out heavy opioid use by a determined user.

Still, proponents see abuse-deterrent opioid formulas as one of a broad range of tools needed to address the deadly abuse epidemic. The Food and Drug Administration is holding a two-day public hearing this week on them, and no doubt some participants will point out correctly that street prices for abuse-resistant opioids are lower than for non-resistant opioids, indicating that addicted users find them less appealing.

Another challenge looms for the next-generation opioids. Their higher price tag compared to older, generic opioids may price out some consumers. And particularly if Congress repeals the Affordable Care Act, requiring that only abuse-deterrent opioids be prescribed could create budgetary pressures (e.g., within Medicaid) that reduce access to opioids for patients in desperate need.