Endo Pharmaceutical’s recent decision to halt sales of Opana ER (oxymorphone hydrochloride) quickly followed the U.S. Food and Drug Administration’s (FDA) request that it remove the abuse-linked opioid pain medication from the market. This is the first time the agency sought to remove a currently marketed opioid pain medication from sale due to the public health crisis of opioid abuse.

In 2015, more than 33,000 people died from opioid overdoses, according to the Centers for Disease Control. Almost half of the deaths involved a prescription medication.

The decision to request the withdrawal of Opana ER from the market arose from the FDA’s determination that the product had “dangerous unintended consequences” and abuse of reformulated Opana ER by injection resulted in a “serious disease outbreak.” The FDA’s decision was based on a review of post-marketing data, which demonstrated a pattern of abuse of Opana ER following the product’s reformulation in 2012. Injection abuse of reformulated Opana ER has been associated with a serious outbreak of HIV and hepatitis C, as well as cases of thrombotic microangiopathy, a serious blood disorder.

Opana ER was first approved in 2006. In 2012, Endo released the new formulation which was intended to make the drug resistant to abuse. At that time, the FDA declined the company’s request to include labeling describing Opana ER’s potentially abuse-deterrent properties. The FDA determined that the data did not show that the reformulation could be expected to meaningfully reduce abuse. Although Opana ER had been reformulated to discourage abuse by crushing or snorting – users began to liquefy and inject the drug.

Had Endo Pharmaceuticals chosen not to remove the product from the market, the FDA planned to require its removal by withdrawing approval. Meanwhile, the FDA informed health care professionals and others of the particularly serious risks associated with the abuse of Opana ER.

A number of lawsuits have been filed, mostly by states and municipalities, alleging that drugmakers downplayed the addictive risks of their opioid painkillers, while certain parts of the country were being devastated by opioid addiction.

Last year, the CDC released new voluntary guidelines for prescribing opioids, asking health care providers to consider alternatives to prescription painkillers, limit the length of treatment, and monitor patients.