Effectiveness of liposomal bupivacaine for pain control examined in study
Vienna (OTS) – Liposomal bupivacaine was introduced 12 years ago to provide long-lasting local pain control. The agent is used as a local anesthetic, particularly in orthopedic procedures. Research work by the MedUni Vienna has now shown the limited effectiveness of the substance. The study was recently published in Anesthesiology, the peer-reviewed journal of the American Society of Anesthesiologists (ASA).
The study was carried out as a collaboration between scientists from the University Clinic for Anesthesia, General Intensive Care Medicine and Pain Therapy and the University Clinic for Clinical Pharmacology with 25 volunteer, healthy test subjects in a randomized, controlled and triple-blinded manner. To control pain, the study participants were randomly assigned to undergo two nerve blocks with bupivacaine, once in the conventional form and once in the liposomal form. Liposomal means that the active ingredient is encapsulated in vesicles called liposomes, which is intended to allow slower release over a longer period of time. “Since the combination of both forms of bupivacaine is recommended, little was known about the effectiveness of using liposomal bupivaine alone in pain therapy during and immediately after operations,” says co-first author Peter Marhofer, summing up the initial situation.
The studies showed that the administration of liposomal bupivacaine led to a successful blockage of pain conduction in around a third of the test subjects, compared to 100 percent after administration of the conventional form. “It can be concluded that liposomal bupivacaine alone is not sufficient to control pain during surgery,” concluded anesthesiologist Peter Marhofer. As far as the longer-lasting postoperative effectiveness is concerned, liposomal bupivacaine led to reduced pain sensitivity in the affected area of the body for over 3.5 days. “However, based on our measurements, this effect cannot be viewed as reliable,” says Marhofer, “since the effectiveness was unpredictable even within a test subject and sometimes decreased and increased several times over time.”
Further research for safe use
As a special form of bupivacaine, which was introduced in 1963, liposomal bupivacaine was developed with the aim of ensuring long-lasting regional pain control. Its function is based on the local blocking of nerve conduction, which prevents pain signals from being transmitted from the anesthetized area to the brain. By extending the duration of action, patients should experience less pain and need fewer opioids after surgery, which in turn should reduce the risk of addiction and other unwanted side effects. In medical practice, liposomal bupivacaine is typically used for local anesthesia, particularly in orthopedic surgeries. “Our study demonstrated unpredictable effects of liposomal bupivacaine in terms of nerve blockade and associated pain relief. Based on our findings, the substance cannot currently be recommended for use in pain therapy during and after operations,” emphasizes study leader Markus Zeitlinger.
Publikation: Anesthesiology
Liposomal Bupivacaine for Peripheral Nerve Blockade: A Randomized, Controlled, Crossover, Triple-Blinded Pharmacodynamic Study in Volunteers;
Markus Zadrazil, Peter Marhofer, Philipp Opfermann, Werner Schmid, Daniela Marhofer, Mira Zeilberger, Lena Pracher, Markus Zeitlinger;
DOI: 10.1097/ALN.0000000000004988
https://pubmed.ncbi.nlm.nih.gov/38558118/
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