More than 63,000 Americans died of opioid drug overdoses last year, more than the number killed in car crashes.

On Wednesday, the FDA approved the first drug designed to treat the symptoms of opioid withdrawal, which can be painful and hook users in a potentially deadly cycle of addiction.

Called Lucemyra, the drug is made by pharmaceutical company US WorldMeds.

Deaths from drug overdoses often start with a last-ditch attempt to subdue painful, flu-like symptoms.

Among the signs that someone has suddenly quit taking a painkiller like OxyCodone or Vicodin: nausea, vomiting, shakiness, and pervasive feelings of panic and depression.

Together, those symptoms constitute withdrawal from opioids. Until today, there were no approved drugs specifically designed to treat that condition, which left few options for people who had been taking the drugs. If they took more painkillers (or a cheaper illegal alternative like heroin), they risked overdose, addiction, and death.

But on Wednesday, the US Food and Drug Administration approved the first medication made expressly to treat signs of opioid withdrawal. The drug will be sold under the brand name Lucemyra by pharmaceutical company US WorldMeds, and its active ingredient is lofexidine. The compound stops the brain from getting flooded with the chemical transmitter that produces most of those flu-like withdrawal sensations.

Mark Pirner, the medical director of clinical research for US WorldMeds, told Business Insider the drug addresses an issue that's central to the problem of opioid use disorder, or OUD.

"When people need to transition from one stage in their treatment for OUD into whatever comes next, withdrawal is a huge obstacle. If that happens and they can't get through it, they're lost," Pirner said.

In clinical trials, lofexidine was pitted against a placebo and found to work better at curbing withdrawal symptoms. People who got it were also significantly more likely to complete a week-long treatment program for stopping opioid use than those who got the placebo.

Another tool in the toolbox of medications for drug use

Methadone. AP Photo/Kevin D. Liles We already have several medications that can curb the most deadly aspects of opioid use disorder, including cravings and the feeling of a high.

Those drugs are buprenorphine and methadone, and researchers have found that when they're available to people with drug use disorder, the number of overdose deaths plummet.

But despite numerous studies suggesting that these drugs save lives, the medications remain difficult to access.

Meanwhile, the only drug that works to curb withdrawal symptoms is a cheap and widely available blood pressure medication called clonidine, which some medical providers commonly prescribe "off label" for withdrawal.

A large review of studies suggested that clonidine and lofexidine were equally effective for cutting opioid withdrawal symptoms. But clonidine hasn't been studied specifically for its potential to treat opioid withdrawal, so it's unlikely the FDA would greenlight it for that use.

Additionally, lofexidine appears to have a slightly lower impact on blood pressure than clonidine, which makes it a bit more appealing to patients and providers.

"This is an FDA-approved drug with clear dosing guidelines," Pirner said. "We hope this will open up opportunities for prescribers."