In a moment he described as “historic,” Gov. Chris Christie on Wednesday signed a sweeping piece of legislation that mandates insurance coverage for up to six months of substance abuse treatment, imposes the nation’s strongest limit on initial opioid drug prescriptions and requires education for patients and doctors about the risks associated with the drugs.

“The epidemic of addiction is incalculable, the numbers are indisputable,” Christie said during a signing ceremony shortly after the Assembly passed the measure 64-1 with five abstentions. “The person who’s in the throes of addiction … [and] realizes he or she needs help, they should not be blocked from the treatment center doors with their lives hanging in the balance.”

Several physicians, lawmakers and insurance company representatives, however, have said the legislation has significant flaws and could have been made better had not leaders of both parties, spurred on by Christie, rushed it through the Legislature. The measure was introduced on Jan. 30.

“The sponsors have no idea how much the bill is going to cost taxpayers and they have no idea how much the insurance mandate will increase the cost of health insurance in the state,” said Assemblyman Jay Webber, R-Morris, who was the sole lawmaker to vote against the bill. “A mandate like this will increase premiums and so we’re going to have fewer people with health insurance at all.”

In addition, several members of the medical community have been critical of the prescription limits imposed under the law, arguing that a one-size-fits-all approach inappropriately interferes with medical practice and disadvantages patients who already have limited access to healthcare.

Christie on Wednesday rejected those arguments.

“The fact is, whatever the cost is of this, it’s certainly less than 1,600 lives a year,” Christie said, referring to the number of New Jersey residents who died from drug overdoses, largely due heroin and fentanyl use, in 2015.

The new law requires health plans to cover the first four weeks of inpatient or outpatient substance abuse treatment without the need for authorization by insurance company officials. It also mandates additional coverage for up to six months of treatment, including medication-assisted treatments, if deemed medically necessary.

The mandate applies only to the roughly 30 percent of New Jersey residents with insurance plans regulated by the state. That includes many public employees and teachers, as well as many people who get coverage through small- or medium-sized businesses or as individuals.

Another part of the law applies statewide and limits to five days — down from the current maximum of 30 — the initial supply of opioid drugs a doctor can prescribe to a patient. Doctors can prescribe opioid drugs beyond five days only after a second consultation with a patient.

Patients being treated in the course of cancer, palliative or end of life care are exempted under the law, which also requires doctors to discuss the risks of opioid drugs with patients before writing a prescription and requires certain health care professionals to receive training on topics related to the drugs.

“What I like about this legislation is that it demonstrates a recognition among policy makers that aggressive prescribing of opioids is fueling the epidemic,” Dr. Andrew Kolodny, executive director of Physicians for Responsible Opioid Prescribing, a national organization formed seven years ago to change prescribing patterns, said in an interview last week.

“The reason we have this epidemic of opioid addiction is because beginning in the 1990s, the medical community started to prescribe opioids much more aggressively than we had in the past,” he said. “And as the prescribing went up, addiction and overdose deaths went right up along with the increase in prescribing.”

According to the Centers for Disease Control and Prevention, sales of prescription opioids quadrupled from 1999 to 2015. Over the same period, the rate of fatal overdoses involving prescription opioids similarly increased, claiming the lives of some 183,000 Americans.

Christie on Wednesday cited another statistic, also used by the American Society of Addiction Medicine, that says four in five new heroin users start out by misusing prescription painkillers.

But many physicians and medical professionals disagree with Kolodny’s assessment that the law is getting at the heart of the problem.

“We do have an epidemic of increasing fatalities, primarily from heroin abusers and drug abusers who have obtained prescriptions illegally,” Dr. Scott Woska, a pain physician and representative of the New Jersey Pain Society, said during a committee hearing on the bill last month. “This is a complex problem that involves education in schools, law enforcement, drug trafficking and access to addiction treatment. Regulating doctors and the prescription process I do not feel would help the societal problem.”

Mishael Azam, chief operating officer for the Medical Society of New Jersey, called on the Legislature to encourage better insurance coverage for non-narcotic alternatives to opioid painkillers and to fully utilize the state Prescription Monitoring Program to prevent abuse rather than constricting medical practice.

Even Dr. Mark Rosenberg, chairman of emergency medicine at St. Joseph's and one of the architects of an innovative Alternatives to Opiates pain management protocol there, expressed doubts about the appropriateness of the prescription limit for all patients.

He said that at a hospital like his, which provides a large amount of charity and underinsured care, asking patients to come back to the hospital after five days to renew a prescription could harm those who cannot afford immediate follow-up care for an ailment and burden the healthcare system.

“If I gave them a prescription for opioids because they needed it, I cannot get them into treatment in five or seven days. The clinic is too damn busy,” he said. “So to have them come back to the emergency department, which is already cited as the place that’s too expensive for care, makes no sense.”

Assemblyman Joe Lagana, D-Paramus, called the law “a step in the right direction” and said that lawmakers were willing to make adjustments to it once they see how it works in the real world.

“We have to work with our medical professionals and addiction specialists to make sure that the law hits the mark by reducing opioid dependence,” he said. “And if it needs tweaking, it deserves a reexamination by the Legislature.”

Christie showed less flexibility on Wednesday. In response to the concerns of medical professionals, Assemblyman Declan O’Scanlon, R-Monmouth, said Wednesday that he and Assemblywoman Nancy Munoz, R-Union, would introduce legislation to change the prescription limit from five to seven days.

“If they send the seven-day limit to me, I’ll veto it,” Christie said.

But he did indicate that more work was to be done on all fronts in dealing with the opioid epidemic, including prevention, treatment and prosecution.

“Today is not the end, it’s the beginning,” he said. “We have a lot more to do.”