* FDA requested withdrawal of drug in June
* Endo expects to incur impairment charge of $20 mln
* Endo shares down as much as 3 percent (Updates with background on opioid , sales data)
July 6 (Reuters) - Endo International Plc said on Thursday it agreed to withdraw its long-acting opioid painkiller Opana ER from the market after the U.S. Food and Drug Administration declared its benefit did not outweigh public health risks associated with opioid abuse.
The company said it would incur a pre-tax charge of about $20 million in the second quarter to write off the drug's value. Endo's shares fell as much as 3 percent.
The FDA called last month for the drug to be withdrawn after an advisory committee concluded in March that the benefit of the drug no longer outweighed the risk. It was the first time the agency had called for the removal of an opioid for public health reasons.
That news sent the company's shares down 12 percent to $12.10. On Thursday the shares fell to $11.05.
Opana ER was approved in 2006. A reformulated version designed to deter abuse was introduced in 2012. The advisory panel concluded that while the rate of nasal abuse fell, rates of intravenous abuse rose.
Sales of Opana ER were $159 million in 2016, less than 5 percent of Endo's overall revenue.
The withdrawal comes amid a nationwide opioid abuse epidemic that the FDA has vowed to combat. FDA Commissioner Scott Gottlieb has made it a top priority for the agency. He has said the agency will continue to "take regulatory steps" in situations where it believes the risks outweigh the benefits.
Opioids killed more than 33,000 people in 2015, according to the Centers for Disease Control and Prevention. About half those deaths involved a prescription painkiller.
A growing body of litigation is piling up against manufacturers of opioid painkillers over claims the drugmakers, including Endo, misrepresented the risks of addiction, overdose and abuse associated with these medicines. (Reporting by Divya Grover and Natalie Grover in Bengaluru; Editing by Martina D'Couto and Andrew Hay)