AUGUSTA — U.S. Sen. Angus King’s push to make the antidote for heroin overdoses available in Maine without a prescription could face opposition from Gov. Paul LePage.

King wrote a letter this month to the CVS pharmacy chain, asking it to make naloxone available over the counter in Maine, as it has done in 15 other states. And Maine lawmakers plan to take up a bill Thursday that would allow pharmacies to make the drug available over the counter.

King, an independent who caucuses with Democrats, said it is crucial to provide easier access to the antidote, given Maine’s high number of fatal heroin overdoses.

But the Republican governor has opposed efforts to increase access to naloxone, and LePage’s spokeswoman, Adrienne Bennett, said Wednesday that she doesn’t expect he will change his position. Regarding the legislative measure, she said, the governor normally does not comment on bills before they reach his desk.

Also known by its trade name, Narcan, naloxone blocks or reverses the effects of opioid medication. It is not addictive and does not produce euphoria.

CVS plans to expand its program to 20 states this year. Walgreens also said this month that it wants to offer naloxone without prescriptions in its pharmacies. But drugstores can’t make the drug available without a prescription without a change in state laws.

LePage has consistently opposed greater access to naloxone.

At a press conference in 2014, he said that giving the antidote to family members of drug users would discourage people from seeking treatment. He said it would send the message: “Go overdose. If you do, by the way, I will be there to save you.”

A 2014 bill that put naloxone in the hands of first-responders became law without LePage’s signature after unanimous approval in the Legislature.

Then, last year, LePage tried to veto a bill that allows immediate family members of drug users to administer naloxone. The bill became law after LePage missed the veto deadline.

After King wrote to CVS, the company asked Assistant Majority Leader Sara Gideon, a Democrat from Freeport, to sponsor a bill to make the practice legal in Maine. Gideon’s measure would require pharmacists to get training on how to administer the drug. It also would require pharmacists to teach any buyers how to use it. The drug is given nasally.

A spokesman for King said, “Senator King does not typically comment on state legislation, but he’s glad to see that the legislature is taking action to clarify state law in a way that can help save the lives of Maine people.”

Gideon said she’s sponsoring the bill because the number of overdoses from heroin and opioids in Maine continues to increase. Maine recorded 208 overdose deaths in 2014, and the Attorney General’s Office says the state is on track to reach between 230 and 250 deaths this year.

The Legislature’s Health and Human Services Committee plans to hold a public hearing on the bill Thursday.

Kenney Miller, co-founder of the Maine Harm Reduction Alliance, said there’s no evidence that naloxone enables drug use. He said drug addiction itself is accompanied by pain.

“It’s a bad experience because it plummets you into sudden withdrawal,” he said. “There is a perception that people will use (the antidote) to push the boundaries. That is blatantly false. It’s a lifesaver.”