Pacira Pharmaceuticals Inc. should not be allowed to claim that its post-surgery pain drug Exparel can be used as a nerve block for regional pain relief, a a U.S. FDA committee concluded.

A nerve block is a form of regional anesthesia injected into nerves to numb a specific area of the body before surgery and reduce pain after the procedure is complete.

The Anesthetic and Analgesic Drug Products Advisory Committee voted 6-4 against recommending the drug for the indication. The panel of expert advisers believes that more research is needed to further support the proposed new indication.

The FDA usually follows the recommendations of its panel but is not obligated to do so.

Exparel is already approved by the regulator for administration into the site of surgery for post-surgery pain relief.

The agency is expected to make a decision on the drug April 6. The supplemental new drug application of Exparel the drug is based on data from two phase 3 trials.