By Trisha Roy and Saumya Joseph

(Reuters) – Independent experts on an FDA advisory panel on Thursday were split over the approval of Durect Corp’s non-opioid painkiller to manage post-surgical pain.

The panel members questioned the drug’s effectiveness and raised concerns over the nausea, vomiting and bruising at the surgical site experienced by some patients during the studies.

Six members voted in favor, while six others voted against the drug Posimir, a reformulated version of the anesthetic bupivacaine that aims to provide pain relief for up to three days after surgery.

“It is slightly better than placebo, but very slightly better, (that) coupled with some potentially minor safety concerns make the benefit to risk calculation challenging,” said Abigail Shoben, a panel member from the Ohio State University who voted against the approval.

The members were also concerned about the way the drug was administered directly into the surgical incision, with some asking for additional studies on the effects of the drug when administered intravenously.

“The data was inconsistent and there are some unknowns that don’t make sense with the rationale I heard,” said Joseph O’Brien, chief executive officer of the National Scoliosis Foundation in Massachusetts, who voted in favor of approval.

“Despite all these concerns, at the end of the day, we do have a need for opioid-sparing medication,” he said.

The FDA has been pushing companies to develop alternatives to opioid-based painkillers, as the United States grapples with the problem of opioid addiction that has claimed the lives of over 700,000 people since 1999.

Durect’s Posimir is expected to provide pain relief for up to 72 hours, while the effects of local anesthetics such as bupivacaine, widely administered as painkillers, last for about four to six hours.

The panel’s recommendation plays an influential role in the FDA’s final decision. The agency had declined to approve Posimir in 2014, citing insufficient safety data.

(Reporting by Trisha Roy and Saumya Sibi Joseph in Bengaluru; Editing by Arun Koyyur and Amy Caren Daniel)