A kit of Naloxone, which can reverse the effects of an opioid overdose. (Andrew Burton/Getty Images)

The Food and Drug Administration announced Tuesday that it will require new warnings about the risk of addiction, abuse, overdose and death for short-acting opioid pain medications, a step toward curbing the epidemic of narcotic use in the United States.

The "black box" cautions for immediate-release medications — powerful narcotics intended for use every four to six hours — also will warn of the danger that chronic use of the drugs by pregnant women can result in newborns who must go through the painful process of withdrawal, known as Neonatal Opioid Withdrawal Syndrome.

In a briefing for reporters, FDA Commissioner Robert Califf called opioid addiction one of the most "urgent and devastating public health crises facing our nation" and said the new labels were just part of the government's larger strategy for addressing it.

But Sen Edward Markey (D-Mass.), who delayed Califf's confirmation while he demanded that the FDA overhaul its approval process for opioid medications, issued a statement saying that "the labels given by the FDA have done little to prevent opioid addiction. Unfortunately, it has taken the FDA far too long to address the grave risks of these drugs that have claimed the lives of thousands this year alone."

Last month, the FDA, which has been criticized as too willing to approve the painkillers and too slow to fight their abuse, outlined a wide-ranging strategy to overhaul its opioid policies.

The new FDA warnings will emphasize that immediate-release opioids should be a last resort for severe pain when other painkillers don't work or can't be tolerated by patients. Dosing information will provide clearer instructions to prescribers about how to administer the drugs and monitor patients, along with a warning not to "abruptly stop treatment in a physically dependent patient," according to an FDA news release.

The warnings will apply to more than 200 short-acting opioid products including widely prescribed medications, such as oxycodone, hydrocodone and others. Those immediate release opioids represent about 90 percent of the products on the market. Similar warnings were added to packaging for extended release medications in 2013, said Douglas Throckmorton, deputy director of regulatory programs for the FDA's Center for Drug Evaluation and Research. In May, he said, the FDA will evaluate whether that labeling change reduced opioid addiction.

The FDA made its announcement even as a congressional oversight committee was probing the causes and effects of the nation's opioid epidemic, and as federal government action to counter the impact of opioids has finally begun to gather momentum.

Last week, the Centers for Disease Control and Prevention issued the first national guidelines for doctors on the use of opioids. They urge physicians to use more caution and to consider alternatives before they prescribe highly addictive narcotic painkillers. The Senate recently passed legislation that would expand drug abuse treatment and prevention.

Deaths from opioid overdoses — both prescription narcotics and illicit street drugs, such as heroin — reached a record of 28,647 in 2014, according to the Centers for Disease Control and Prevention. Overdoses from all forms of drugs now kill more Americans than car accidents or firearms.

One study shows that 14 percent of pregnant women have been prescribed the powerful opioid medications for pain. Another revealed a quadrupling in the number of drug-exposed children in neonatal intensive care units.

FDA officials said the new warnings would affect 87 brand-name drugs and 141 generics, and would be completed by the end of 2016. Soon after that, drug manufacturers will be expected to include the highlighted warnings on packaging and updated guides for using the medications. Current packages that lack the warnings will not be recalled.

The new labeling also will include warnings about an interaction with other medicines that can cause a serious central nervous system condition called serotonin syndrome, the chance of a rare disorder called adrenal insufficiency and the possibility of decreased sex hormone levels.

Bill Soller, president of Biomedical Regulatory Consulting in Houston, who studied drug labeling when he was a professor at UC San Francisco, said he was impressed with the "comprehensiveness" of the FDA approach. He said the primary impact "will be on physicians, in terms of how they prescribe and how they monitor opioid use with their patients."

Still, the new instructions will only be effective if health care providers and consumers embrace and follow them, Soller said.

"It's up to the system of care to put it into the requirements for their personnel," he said.

Read more:

When life begins in rehab: A newborn heals after a mother's heroin addiction.

MIT scientists find evidence that Alzheimer’s ‘lost memories’ may one day be recoverable

’Siri, I want to commit suicide’ and other statements likely to yield unhelpful responses from your phone

Study finds short men get short of end stick in life.