Non-Opioid Analgesic Gets Another Poor Grade for Pain Relief

By Pat Anson, PNN Editor

An expensive analgesic drug that’s often touted as a safer alternative to opioids is not reliable or effective as a pain reliever, according to a new study.

Exparel is an injectable form of liposomal bupivacaine, a non-opioid local anesthetic used for post-operative pain and as a nerve block to numb parts of the body during surgery.

Because Exparel is a proprietary formulation of bupivacaine, Pacira BioSciences has priced it 10 times higher than generic bupivacaine. A 20 milliliter vial of Exparel costs about $376, compared to $38 for a same size vial of bupivacaine.

Some anesthesiologists have questioned whether Exparel is actually worth the higher cost, saying its effectiveness in relieving post-operative pain is “clinically unimportant” and no different than other local anesthetics.  

To see if they might be right, researchers at the Medical University of Vienna recruited 25 healthy volunteers for a blinded clinical study in which participants received two nerve blocks about a month apart, one with plain bupivacaine for pain control and the other with liposomal bupivacaine (Exparel).

"Since the combination of both forms of bupivacaine is recommended, little was known about the effectiveness of the use of liposomal bupivacaine alone in pain therapy during and immediately after surgery," wrote lead author Peter Marhofer, MD, a Professor of Anesthesia and Intensive Care Medicine at MedUni Vienna.

The study findings, recently published in the journal Anesthesiology, show that Exparel alone blocked pain in less than a third of the volunteers, compared to everyone who received plain bupivacaine.

“Given complete sensory blockade in merely 32% of cases, as compared to 100% with plain bupivacaine, liposomal bupivacaine does not emerge from our study as a suitable ‘sole’ local anesthetic for intraoperative regional anesthesia,” said Marhofer.

Those who did get pain relief from Exparel say it reduced their post-operative pain for up to 3.5 days. But because its effects varied widely from subject to subject, researchers don’t consider it a reliable analgesic when used alone.

"Our study showed unpredictable effects of liposomal bupivacaine in terms of nerve block and associated pain relief. Based on our findings, the substance cannot currently be recommended for use in pain therapy during and after surgery," said co-author Markus Zeitlinger, MD, an Associate Professor of Clinical Pharmacology at MedUni Vienna.

Pacira did not respond to a request from PNN for comment on the study. In the past, the company has aggressively promoted Exparel and used hardball tactics to silence critics.

In 2021, Pacira filed a lawsuit against the American Society of Anesthesiologists for publishing “false and misleading conclusions” in the journal Anesthesiology that said Exparel worked no better than other bupivacaine products. The lawsuit was later dropped.

In 2014, Pacira took the unusual step of filing a lawsuit against the FDA, after the agency sent a warning letter to Pacira for off-label marketing of Exparel. Pacira won that case in an out-of-court settlement when the FDA withdrew its warning letter and approved the use of Exparel for more types of post-operative pain.

Over the years, Pacira has paid nearly $34 million to doctors to help promote Exparel, according to Open Payments. That strategy backfired In 2020, when Pacira paid $3.5 million to settle allegations that it gave kickbacks to doctors in the form of fake research grants.

Pacira has also been active politically, spending over $3 million on lobbying and campaign donations since 2018, according to OpenSecrets. In 2019, the company hired former New Jersey governor Chris Christie as a consultant for $800,000 and lucrative stock options. Christie had recently chaired President Trump’s opioid commission, which issued a report recommending that hospitals use more non-opioid pain relievers.

Pacira is also bankrolling Voices for Non-Opioid Choices, an advocacy group that is lobbying the Biden administration for early implementation of the NOPAIN Act. Passed by Congress in late 2022, the law requires Medicare and Medicaid to pay for Exparel and other non-opioid treatments in outpatient surgical settings, starting in 2025. Supporters of the bill want the timetable moved up to 2024, which would generate millions of dollars in additional revenue for Pacira.