In addition to the pill limits, Kasich said the new rules require doctors to provide a specific diagnosis and procedure code for every painkiller prescription they write.
And Kasich warned that doctors who don’t follow the rules will lose their licenses.
“You’re going to have to abide by these rules,” he said.
The new limits, which have gotten the blessing of the Ohio Board of Pharmacy, the State Medical Board, and the state’s dental and nursing boards, do not apply to patients who take prescription painkillers for cancer treatment or to dying patients who are already receiving hospice care, Kasich said.
"Health care providers can prescribe opiates in excess of the new limits only if they provide a specific reason in the patient’s medical record," the state said in a statement.
Let our news meet your inbox. The news and stories that matters, delivered weekday mornings.
Kasich also said lawmakers and doctors can’t do it alone and that Ohioans are going to have to speak up when they see something if they want to vanquish this plague.
“We all need to stick our noses into somebody else’s business,” he said.
Kasich’s announcement came a day after GOP lawmakers introduced bills in the state House and Senate that take a similar approach by setting dosage limits and making drug counseling and addiction education available online.
Previously, doctors in Ohio were allowed to write painkiller prescriptions for up to 90 days, according to the Columbus Dispatch.
The Ohio medical establishment has, in recent years, moved to limit the amount of painkillers being prescribed by issuing guidelines. Now, it’s law.
“By reducing the availability of unused prescription opiates, fewer Ohioans will be presented with opportunities to misuse these highly addictive medications,” Kasich said in a statement.
The governor’s announcement came on the heels of President Donald Trump’s unveiling of a special commission — headed by New Jersey Gov. Chris Christie — to combat the opioid epidemic.
Christie, who like Kasich is a Republican, signed into law last month a five-day limit on the amount of opioids that can be prescribed by a doctor.
Ohio is one of several Rust Belt states that has been struggling to contain a raging opioid epidemic.
This year, the state’s capital city of Columbus has been average one fatal overdose per day from fentanyl — a powerful painkiller that the U.S. Drug Enforcement Agency says is 25 to 50 times more powerful that heroin and packs 50 to 100 times more punch than morphine.
And there were so many fatal drug overdoses in four other Ohio counties that the local coroners had to truck in “cold storage mass casualty” trailers from Columbus to stash the bodies because they ran out of room in their morgues.
While many Americans get hooked on locally prescribed painkillers, lawmakers say the drug cartels have made a mint feeding their habits by smuggling Chinese-made fentanyl and other opioids into the country.
Corky Siemaszko is a senior writer for NBC News Digital.