New restrictions would increase the punishment for illegal use of drugs like Vicodin, but would not impact patients using them legally.

The U.S. Food and Drug Administration (FDA) has announced plans to place greater restrictions on hydrocodone-containing drugs amid a rising tide of addiction and abuse.

In a statement, the FDA says it has been trying to balance the needs of those using hydrocodone to treat pain versus those who acquire it illegally for abusive purposes.

“In recent years, the FDA has become increasingly concerned about the abuse and misuse of opioid products, which have sadly reached epidemic proportions in certain parts of the United States,” the FDA said in a statement.

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In 2009, the U.S. Drug Enforcement Administration (DEA) asked the U.S. Department of Health and Human Services (HHS)—the FDA’s parent agency—for a recommendation of reclassification.

Four years later, following a public outcry, the FDA announced Thursday its plans to submit a formal recommendation to the HHS to classify hydrocodone drugs as Schedule II controlled substances.

Hydrocodone drugs are currently registered as Schedule III controlled substances, meaning that they have a “potential for abuse less than substances in Schedules I or II, and abuse may lead to moderate or low physical dependence or high psychological dependence,” according to the DEA.

Schedule II drugs, however, “have a high potential for abuse which may lead to severe psychological or physical dependence.” Other Schedule II prescription painkillers include oxycodone (OxyContin, Percocet), hydromorphone (Dilaudid), methadone, morphine, opium, and codeine.

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Hydrocodone is a semi-synthetic opioid derived from opium. By itself, it is currently classified as a Schedule II substance, but it is Schedule III if used in combination with other ingredients. Such is the case for drugs like Vicodin.

Prescription painkillers have been under more scrutiny lately as experts discover that many people are addicted to them, sometimes leading to overdose deaths, which the U.S. Centers for Disease Control and Prevention (CDC) says have “reached epidemic levels.”

Many experts attribute the resurgence of heroin use in the U.S. to the rise in prescription drug abuse. Drug-related overdoses are now the leading cause of accidental death for Americans ages 25 to 64, and 60 percent of drug overdoses in 2010 were from prescription drugs, a four-fold rise over the last decade.

The reclassification of hydrocodone combination drugs won’t affect patients who take the drugs with a legal prescription from their doctors.

However, changing the scheduling classification will have legal ramifications for those convicted of possessing or distributing the drugs illegally. While maximum punishments vary based on local, state, and federal laws, Schedule II drugs carry stiffer sentences than Schedule III drugs.

Under federal sentencing guidelines, any amount of a Schedule I or II controlled substance carries a maximum of 20 years and fines of up to $1 million at first offense, while Schedule III drugs carry a maximum of 10 years and up to $500,000 in fines.

Fourteen states have passed 911 Good Samaritan laws, which offer limited immunity to people who get help for someone suffering a potentially fatal overdose. As many as 10 other states are pursing similar laws.