Extradural S(-)-bupivacaine: comparison with racemic RS-bupivacaine.

Bupivacaine has a chiral centre and is currently available as a racemic mixture of its two enantiomers: R(+)-bupivacaine and S(-)-bupivacaine. Preclinical studies have demonstrated that there is enantiomer selectivity of action with the bulk of central nervous system and cardiovascular toxicity residing with the R(+) isomer. The aim of this study was to compare the clinical efficacy and safety of S(-)-bupivacaine with racemic RS-bupivacaine for extradural anaesthesia. We studied 88 patients undergoing elective lower limb surgery under lumbar extradural anaesthesia who received 15 ml of 0.5% or 0.75% S(-)-bupivacaine, or 0.5% RS-bupivacaine in a randomized, double-blind study. There was no difference in onset time, maximum spread of sensory block or intensity of motor block between the three groups. Duration of sensory block was significantly longer for 0.75% S(-)-bupivacaine. We conclude that S(-)-bupivacaine has similar local anaesthetic characteristics to RS-bupivacaine when used for extradural anaesthesia.

[1]  B. Graf,et al.  Stereospecific Effect of Bupivacaine Isomers on Atrioventricular Conduction in the Isolated Perfused Guinea Pig Heart , 1997, Anesthesiology.

[2]  J. Tamargo,et al.  Stereoselective block of cardiac sodium channels by bupivacaine in guinea pig ventricular myocytes. , 1995, Circulation.

[3]  T. N. Calvey.  Isomerism and anaesthetic drugs , 1995, Acta anaesthesiologica Scandinavica. Supplementum.

[4]  K. Samii,et al.  Myocardial uptake of bupivacaine: II. Pharmacokinetics and pharmacodynamics of bupivacaine enantiomers in the isolated perfused rabbit heart. , 1993, Anesthesia and analgesia.

[5]  M. Behbehani,et al.  Enantiomer-Specific Effects of an Intravenously Administered Arrhythmogenic Dose of Bupivacaine on Neurons of the Nucleus Tractus Solitarius and the Cardiovascular System in the Anesthetized Rat , 1992, Regional Anesthesia & Pain Medicine.

[6]  E. Carmeliet,et al.  Stereoselective effects of the enantiomers of bupivacaine on the electrophysiological properties of the guinea‐pig papillary muscle , 1991, British journal of pharmacology.

[7]  G. Thompson,et al.  Comparison of 0.5% ropivacaine and 0.5% bupivacaine for epidural anesthesia in patients undergoing lower-extremity surgery. , 1990, Anesthesiology.

[8]  L. Hondeghem,et al.  Mechanism for Bupivacaine Depression of Cardiac Conduction: Fast Block of Sodium Channels during the Action Potential with Slow Recovery from Block during Diastole , 1985, Anesthesiology.

[9]  G A Albright,et al.  Cardiac arrest following regional anesthesia with etidocaine or bupivacaine. , 1979, Anesthesiology.

[10]  F. Reynolds,et al.  An intradermal study of the local anaesthetic and vascular effects of the isomers of bupivacaine. , 1978, British journal of clinical pharmacology.

[11]  G. Åberg.  Toxicological and local anaesthetic effects of optically active isomers of two local anaesthetic compounds. , 1972, Acta pharmacologica et toxicologica.