The U.S. Drug Enforcement Administration will begin using emergency measures to categorize new fentanyl-like drugs as controlled substances, an effort to keep up with the rapidly evolving permutations of the powerful opioid drug.

A 1986 law, the Federal Analogue Act, allows the government to temporarily classify so-called "designer drugs" as illegal in order to keep up with chemists who make small changes to a drug's molecular structure in order to get around drug laws.

The Justice Department has used that law six times in the last two years to go after variants of fentanyl, the deadly synthetic opioid that is 50 times more powerful than heroin. But that system is cumbersome, and often requires police and prosecutors to jump procedural hurdles to get convictions.

When the new order takes effect next month, the agency will be able to make those determinations on new variants immediately, USA Today reports.