The US Food and Drug Administration (FDA) has ordered that stronger warnings be placed on the painkillers Darvocet and Darvon but has allowed the drugs to remain on the market despite local pressure and a complete ban in Europe.

The drug known generically as propoxyphene is widely used in the US but has attracted attention following evidence of deadly overdoses and suicides.

The FDA has ordered that a boxed warning be placed on the drug label and that a pamphlet stressing the risks of overdosing be distributed to patients.

The US drug regulator counterpart in Europe, the European Commission has recently recommended that all countries within the EU ban the drug completely.

The FDA has also ordered that manufacturer Xanodyne Pharmaceuticals conduct research to study the effect of higher-than-recommended doses on patients’ hearts.

According to the FDA, 21 million people used propoxyphene-containing drugs in 2007. Studies from the government’s Drug Abuse Warning Network claim that in the same year 503 Darvon-related deaths were recorded, about 20% of which were classified as suicides.