ST. LOUIS — A new weapon to fight heroin and painkiller addiction could be on the way — an implant that goes in a recovering addict’s arm to deliver a drug that quells cravings for up to six months.

“The longer you keep them sober, the longer they stay stable, learn coping skills and go from there,” said Dr. Azfar Malik, CEO of Centerpointe Hospital for behavioral health in St. Charles.

Probuphine implants received preliminary approval in January from an advisory committee for the Food and Drug Administration, which is expected to give its full endorsement next month. The implants release a steady flow of buprenorphine, which is available in oral form to block cravings and reduce withdrawal symptoms. The drug binds to opiate receptors in the body, but doesn’t produce the same high.

The opiate epidemic shows no signs of slowing, despite increased access to buprenorphine and other addiction-fighting prescription drugs. About 30,000 Americans died of overdoses from opiates, including prescription painkillers and heroin, in 2014. The death rate has nearly quadrupled since 2000, according to the Centers for Disease Control and Prevention.

Supporters of the implant tout its advantage in patient compliance with treatment, since the need to take a daily dose is eliminated. It also reduces the risk of diversion, the practice where users resell their pills or trade them for heroin on the black market.

Several patients in St. Louis received probuphine implants as part of a clinical trial overseen by Malik.

Donna Nevels, of Bethalto, became addicted to prescription painkillers after oral surgery and fell into a deep depression. Last year she completed outpatient treatment at Centerpointe. As part of a clinical trial, she received the implant and oral buprenorphine, one of which was a placebo.

Nevels, 43, said the implant takes away the addict’s choice to remain in treatment, which can be an obstacle.

“I think that if people have an option to put the medicine in their mouth every day, there could be potential room for somebody to relapse,” she said. “Where if the implant is there, there is no craving.”

Other options in opiate addiction include methadone, another opiate that doesn’t produce the same high, but is available only at specialized clinics that distribute the drug daily because of its potential for abuse. Naltrexone blocks the effects of opiates and is also available in a once monthly shot called Vivitrol. Naloxone, better known by brand name Narcan, can reverse an opiate overdose if given immediately, but is not a long-term fix.

Buprenorphine is considered to be the best available option because it limits cravings and does not cause withdrawal symptoms. Because of the chance of the drug getting diverted to other people, doctors are only allowed to prescribe buprenorphine to 100 patients, but the White House has recommended the rule be expanded to 200 patients.

The implant includes four rods, smaller than matchsticks, that work like hormonal birth control implants to slowly release the medication when inserted underneath the upper arm. Candidates for the implant must be stable in their recovery and already taking a low dose of oral buprenorphine. Proponents of the implant said it could be useful in the prison population and among rehabilitation patients to ensure compliance. Those being released from secure environments are at high risk for relapse and could also be good candidates, supporters said.

Doctors who insert and remove the implant under a local anesthesia would require some training. The company marketing the implant, New Jersey-based Braeburn Pharmaceuticals, did not release any information on its cost. Whether it would be covered by insurance is not yet known.

Critics who testified to the FDA committee said the effectiveness of the implant has not been proved in enough patients. Some said that intravenous drug users might not be averse to removing the implant themselves and reselling it. They also raised questions about the long-term viability of the implants, since former drug addicts can require medication for years to avoid relapsing.

Another downside with a six-month implant is the potential for fewer doctor visits for behavioral therapy, said Percy Menzies, president of Assisted Recovery Centers of America, a local addiction center.

“Behavioral modification is a very important part of recovery, we can’t just give them a medication and expect them to get well,” he said.

Still, Menzies said the benefits of the implant outweigh the risks.

“We are looking forward to any new weapon because the heroin tsunami is unremitting,” he said. “By introducing the implant you have a fighting chance of people staying in treatment.”