Modification of Bupivacaine-Induced Myotoxicity with Dantrolene and Caffeine In Vitro

Plank, Christoph MD*; Hofmann, Petra MD*; Gruber, Michael PhD*; Bollwein, Gabriele*; Graf, Bernhard M. MD, MSc*; Zink, Wolfgang MD; Metterlein, Thomas MD*

doi: 10.1213/ANE.0000000000000988
Anesthetic Pharmacology: Research Report

BACKGROUND: Local anesthetics, especially bupivacaine, have myotoxic effects in clinically used concentrations and context. Detailed mechanisms of these effects are unknown, but an increase in intracellular calcium levels is suspected to be the most important trigger. Dantrolene and caffeine modify cellular calcium release from the sarcoplasmic reticulum. The aim of our study was to investigate the effect of dantrolene and caffeine on bupivacaine-induced myotoxicity in vitro.

METHODS: A cell culture model of primary muscle cells of BALB/c AnNCrl mice was established. Cells were incubated simultaneously with increasing concentrations of bupivacaine, dantrolene, and caffeine. The fraction of dead cells was calculated after staining with propidium iodide and analysis by flow cytometry. The half-maximal inhibitory concentration of bupivacaine was calculated for each concentration. Group differences were determined by using 1-way analysis of variances with subsequent post hoc 1-way Dunnett t test.

RESULTS: Both dantrolene and caffeine alone had no effect on muscle cell survival. Increasing concentrations of bupivacaine caused increasing cell death. Dantrolene dose-dependently reduced the fraction of necrotic cells, whereas caffeine dose-dependently increased the fraction of dead cells.

CONCLUSIONS: Dantrolene attenuated, and caffeine enhanced, bupivacaine-induced myotoxicity, presumably by modifying sarcoplasmic calcium release. This indicates that intracellular calcium release is an important factor for local anesthetic–induced cell death.

Published ahead of print September 29, 2015

From the *Department of Anesthesiology, University Hospital Regensburg, Regensburg, Germany; and Department of Anesthesiology and Intensive Care Medicine, Klinikum Ludwigshafen, Ludwigshafen, Germany.

Accepted for publication July 20, 2015.

Published ahead of print September 29, 2015

Funding: None.

The authors declare no conflicts of interest.

Address correspondence to Christoph Plank, MD, Department of Anesthesiology, University Hospital Regensburg, 93053 Regensburg, Germany. Address e-mail to

© 2016 International Anesthesia Research Society