Decisions about drug safety in the US have been the purview of the federal Food and Drug Administration (FDA) for more than a century. But state officials across the country are challenging the agency's authority by rebelling against an FDA decision to approve a powerful new painkiller that many worry could worsen the nation's growing crisis of opioid abuse and addiction.

On 27 March, the governor of Massachusetts, Deval Patrick, declared a statewide ban on the prescribing and dispensing of Zohydro, an extended-release formulation of hydrocodone that received FDA approval last October against the advice of the agency's review panel. Vermont's governor Peter Shumlin followed suit on 3 April, issuing an emergency order that would make it harder for doctors to prescribe Zohydro. And as Nature Medicine went to press, the New Hampshire legislature was considering a bill that would temporarily prohibit sales of Zohydro until the drug's manufacturer, Zogenix, designed a version of the narcotic that had abuse-deterrent properties to prevent snorting or injecting for a high.

These measures could have far-reaching implications for drug regulation in the entire country. A state ban against Zohydro “would be disruptive,” says Larry Gostin, a health law scholar at Georgetown University in Washington, DC. “You don't want to set a precedent that, not just with this drug but with any drug, states can go their own way. I think it would open the floodgates.”

Zogenix is fighting back, at least in Massachusetts. On 7 April, the California-based drugmaker sued the state, contending that the governor's ban was unconstitutional because it preempted federal law. Zogenix points out that the FDA had considered requiring an abuse-deterrent formulation of Zohydro, but the agency ultimately decided that the drug's benefits outweighed the risks. The company also argues that Zohydro is unique from other hydrocodone products such as Vicodin in that it does not contain acetaminophen, which can cause liver failure in people who use such painkillers over a long period.

Many heads of the hydro: Previous forms of hydrocodone have also contained acetaminophen. Credit: DBA Images / Alamy

So far, the tide has turned in Zogenix's favor. On 15 April, the federal judge overseeing the Massachusetts case granted the company's request for a preliminary injunction that temporarily halts the state's ban on Zohydro while the lawsuit plays out. Although no final decision had been made at press time, Patrick told reporters on 16 April that his administration was unlikely to appeal the injunction due to the time and resources involved. He also noted that opioid abuse is a much larger problem than just one drug.

The ceiling can't hold us

If the legal dispute proceeds in Massachusetts or elsewhere, one court case that is likely to be cited is Wyeth v. Levine. In that 2009 ruling, the US Supreme Court found that Wyeth, a drug company now owned by Pfizer, was liable under Vermont state law for not cautioning against a potential side effect of an anti-allergy medication even though the FDA had deemed the drug's warning label acceptable. The court concluded that “federal labeling requirements create a floor, not a ceiling, for state regulation.”

Against this backdrop, Kate Greenwood, a health and pharmaceutical law scholar at Seton Hall University in New Jersey, thinks that any state has a “strong legal case” for raising the regulatory bar on Zohydro as formulated. The state would not be “implementing its own drug and device approval process,” Greenwood notes. As she points out, state officials are simply saying, “This one drug needs abuse-deterrent features before we allow it to be approved in our state.”

But if any state prevails, there could be unintended consequences, cautions James Blumstein, director of the Health Policy Center at Vanderbilt University in Nashville, Tennessee, including the “risk of destroying the national market for drugs,” he says. Rather than a uniform drug regulation policy, it will be a “patchwork” that will ultimately end up raising drug costs and complicating interstate commerce. “What happens if people go across state lines to fill a prescription? Will it be illegal to possess a drug that's illegal in one state but has been lawfully prescribed in another?” he questions.

Allowing one state to ban Zohydro could also open the door for states to ban drugs for reasons related to politics, not public health safety. For example, some states could try to prohibit contraception; others might try to protect local manufacturers from competition or ban expensive drugs to control health care costs.

“The health problems and concerns of the [Massachusetts] governor are very valid ones,” Gostin says, “but he needs to use different channels.”