Officials Tuesday hailed a new program that places heroin antidotes in the hands of MTA police officers, saying unequivocally that $40,000 worth of overdose blockers will save lives.

At a news conference at Penn Station, state Attorney General Eric Schneiderman said people who inhale the drug naloxone wake up from an overdose and can then be easily admitted into treatment.

He said the MTA is an important place to keep a stock of naloxone because "this is how everyone travels to purchase drugs." On a train, especially long-haul routes like the Long Island Rail Road or Metro North, there are no health care facilities onboard. "The only hope you have is that the police would have naloxone."

Already, MTA police are trained to use defibrillators, perform CPR and handle diabetic emergencies, said MTA Police Chief Mike Coan. Though he did not point to specific examples, he said that officers may have prevented overdoses in the last five months had they been equipped with naloxone. With heroin use apparently on the rise, Schneiderman has led a campaign to stem deaths statewide, securing $5 million to make naloxone available to police departments that request it. Each kit costs about $60.

"The stigma attached to heroin seems to have been lost," he said.

Susan Salomone, of Putnam County, lost her son Justin two years ago. He died of a heroin overdose at 29. She attended the news conference and has helped Schneiderman lobby for funding.

"The police force came first just a few minutes after we called, but they didn't have any [of the antidote]," said Salomone, who's the co-founder of Drug Crisis in Our Backyard. Paramedics did have the antidote, but by the time they arrived it was too late.

Each naloxone kit consists of a bag or pouch containing two syringes of naloxone, two atomizers for nasal administration, sterile gloves and a booklet on the use of the drug, according to the attorney general's office.

An MTA spokesman said two officers will get the antidotes right away. Three divisions in the MTA police forxe - amounting to more than 50 officers - will be trained by early fall. Eventually the entire force of 670 officers will be trained and supplied with kits.