A Caribou man is suing the Maine Department of Corrections for refusing to allow him to receive medication in prison to treat his opioid use disorder.

Zachary Smith, 30, of Caribou, is being denied his rights to medication in prison under the Americans with Disabilities Act, according to the lawsuit filed by the American Civil Liberties Union in U.S. District Court in Portland on Thursday. Smith’s Eighth Amendment rights, which prohibit cruel and unusual punishment, are also being violated, the suit says.

Smith takes buprenorphine, or Suboxone, which is used as a long-term drug to help people recover from opioid use disorder. Some are on a maintenance dose of Suboxone for years, and medication-assisted treatment is considered the “gold standard” for opioid treatment by addiction experts.

Smith is scheduled to report to prison in September, either at the Aroostook County Jail or Maine Correctional Center in Windham, for a nine-month sentence for a domestic assault against his father, according to the lawsuit.

Some states, including Rhode Island, New York and Florida, allow medication-assisted treatment in jails and prisons.

Zachary Heiden, ACLU of Maine’s legal director, said Smith was denied his medication during a short stint in the Aroostook County Jail this year and was told that he could not have Suboxone while he’s at the state prison in Windham. The ACLU wrote a letter to the Maine Department of Corrections asking for Smith to have access to the medication but received no response, Heiden said.

“Denying needed medication to people with opioid use disorders serves absolutely no good purpose, and actually undermines the important goal of keeping people off of opiates,” Heiden said in a statement. “Going to prison shouldn’t be an automatic death sentence, but that is the chance we take when we cut prisoners off from adequate medical care.”

The lawsuit said that “opioid use disorder is a chronic relapsing condition that requires medically appropriate treatment just like other chronic diseases. Once patients start on MAT (medication-assisted treatment), they need to be maintained on that treatment under medical supervision to give them the best chances of success. Forced withdrawal is not medically appropriate for patients being treated with MAT. It disrupts their treatment plan, leading to a seven-fold decrease in continuing MAT after release. Death is three times as likely for people out of treatment versus when in treatment.”

Maine Department of Corrections Commissioner Joseph Fitzpatrick told the Press Herald he couldn’t comment.

“If we’re being sued, I can’t speak about that,” said. “Once they’ve filed, I’m not able to comment.”

Maine is in the midst of an opioid crisis, with 418 Mainers dying of drug overdoses in 2017, and the state on track to experience a similar number of overdose deaths this year.

Heiden said it’s “easier for people to get illegal drugs in prison than it is to get their doctor-prescribed medication, and that doesn’t make any sense. We know that the criminal justice system can’t solve the opioid crisis, but the least it can do is not make matters worse.”