A Methuen plan has pleaded guilty to shipping narcotics to federal prisoners.

Tuere Barnes, 43, pleaded guilty in federal court in Boston to one count of providing contraband in prison. According to a plea agreement, Barnes faces a maximum penalty of 20 years in prison and a fine of $250,000. U.S. District Court Judge Allison D. Burroughs released Barnes under personal recognizance under standard release conditions and scheduled sentencing for Wednesday at 1 p.m.

Federal prosecutors say that Barnes was able to ship a package containing 460 sublingual strips laced with buprenorphine to an inmate at Federal Correctional Institution, Danbury, in Connecticut, in late January of 2023. Buprenorphine is an opioid medication used to treat opioid addiction and is a controlled substance under law.

Sublingual — meaning placed under the tongue — strips of buprenorphine are marketed under the brand name Suboxone, which was approved by the FDA in October 2002.

“Buprenorphine,” according to a U.S. Department of Justice bulletin, “is an opioid (synthetic opiate) partial agonist and thus can produce the euphoria, analgesia, and sedation associated with opiates; however, while it stimulates the same brain receptors as full opiate agonists such as heroin and morphine, buprenorphine produces a lesser degree of sedation and respiratory depression than those drugs and causes no significant impairment of cognitive or motor skills.”

While the drug is intended to reduce “cravings for heroin and other opiates and (reduce) withdrawal symptoms,” the drug is itself an opioid and can carry its own risks of abuse, the DOJ states.