The nation’s top federal health agency urged doctors to avoid prescribing opiate painkillers for patients with chronic pain and benzodiazepines, saying the risks from such drugs far outweigh the benefits for most people.

In the Food and Drug Administration’s latest move to help stem the tide of drug overdoses, it is now requiring “black-box warnings” (Black-box warnings, also known as boxed warnings, are the FDA’s highest-level warning) on the dangers of using opioids (painkillers) in combination with benzodiazepines (anxiety) drugs commonly used to treat neurological and psychological conditions including seizure, anxiety and insomnia.

Both opioids such as Hydrocodone and Oxycodone, and benzodiazepines, such as Valium, Xanax, Restoril, Ambien, Lunesta and Ativan can slow the central nervous system. Using them together can lead to extreme sleepiness, respiratory distress, coma and death.

Clinical guidelines from the U.S. Centers for Disease Control and Prevention (CDC) have existing label warnings regarding combined use caution prescribers about co-prescribing opioids and benzodiazepines to avoid potential serious health outcomes. The actions of the FDA today are consistent with the CDC.

Experts say the increased risk lies in how the two types of drugs interact. Taken together, they can depress the respiratory system severely, to the point where a patient can stop breathing. That is essentially the message health officials want the FDA to include on labeling for both types of drugs, in a warning that says using both together “reduces the margin of safety for respiratory depression and contributes to the risk of fatal overdose, particularly in the setting of misuse.”