A Salix Pharmaceuticals (NASDAQ:SLXP) constipation drug that failed to win regulatory approval last year will be up for review by a Food and Drug Administration advisory committee.

A date for the advisory panel meeting for the drug Relistor has not yet been set but the agency Salix said today that the FDA has said it will take action on the drug after receiving input from the advisory board.

Relistor is a subcutaneous injection for treating constipation caused by opioid drugs. Opioids, used to treat chronic pain, have the side effect of causing constipation. Salix licensed Relistor from New Jersey-based Progenics Pharmaceuticals (NASDAQ:PGNX) in 2011. The drug is already approved for use in patients with advanced illness and who suffer from opioid-induced constipation. Salix has been seeking to been seeking to expand use of Relistor to patients who have chronic pain.

According to Salix, the FDA said it called for an advisory committee meeting because of cardiovascular concerns for another drug in the same class that was also developed to treat opioid-induced constipation in patients with chronic pain. The FDA also noted that the Salix application for Relistor lacked long-term safety data compared against a control population, which would be needed to rule out a cardiovascular risk.

“FDA needs to provide consistent advice regarding the need for Major Adverse Cardiovascular Event (MACE) studies to applicants developing drug products in this class for this indication,” the agency told Salix. “For this reason, a broader discussion of the potential for cardiovascular events across the drug class is necessary.”

The advisory panel will include pain, gastrointestinal, safety and cardiovascular experts. Any recommendations from the panel are not binding to the FDA but the agency takes them into account as it makes its decisions.

Salix said that it is not possible to determine how long the process will take but the company continues to believe “a conclusion could be reached during 2013.”