Opioid painkiller benefits fall short of abuse risks

The benefits derived from the use of Endo International Plc’s opioid drug no longer outweighs its risks, according to an FDA advisory panel. As opioid abuse, overdose and addiction have reached epidemic proportions in the United States, partly due to unrestricted prescription of narcotic painkillers, as well as the paucity of access to substance-abuse treatment programs, the FDA has undertaken review of the uses of the painkiller in a variety of settings. Eighteen panelists recommended that the risks of the reformulation eclipse the benefits, while eight disagreed and one member abstained from voting. The FDA generally follows advisory panel recommendations, but is not required to do so.

The FDA advisory panel reviewed the abuse rate of Endo’s Opana® ER – a long acting painkiller similar to oxymorphine and other oxymorphone drugs. Opana was approved in 2006, and in 2012, the drug maker introduced a new formulation to attempt to deter abuse of the drug. Although the reformulation (in nasal form) reduced abuse rates, intravenous abuse increased in the same timeframe. The panel was unable to conclude whether this rise was related to the reformulation, but noted that the trend was observed before the reformulation. Additionally, abuse rates for similar oxymorphone drugs are as high as Opana.

One factor that triggered the advisory panel’s review was the increased rate of rare blood disorders and human immunodeficiency virus (HIV) linked to the IV abuse of the reformulation.

Some advisory panel members expressed concerns that the voting question posed did not permit consideration of the risk-benefit profile for an intended user versus use by an addict. Others questioned whether withdrawing the product would stop an addict from abusing other opioids, or whether oxymorphone was still an integral part of the arsenal of treatments for chronic pain.