Levobupivacaine is the S(-) enantiomer of bupivacaine.
It is prepared as a sterile, colourless solution (pH 4.0-6.5) containing levobupivacaine hydrochloride equivalent to 2.5 mg/ml, 5.0 mg/ml and 7.5 mg/mL of levobupivacaine.
The pKa of 8.1 for levobupivacaine is the same as that of bupivacaine. Protein binding is more than 97%, mainly to alpha-1-acid glycoprotein.
It is extensively metabolised, with no unchanged levobupivacaine detected in the urine or faeces. In vitro studies showed that cytochromes CYP3A4 and CYP1A2 mediate the metabolism of levobupivacaine to desbutyl levobupivacaine and 3-hydroxy levobupivacaine, respectively. The 3-hydroxy levobupivacaine appears to undergo further transformation to glucuronide and sulphate conjugates.
Animal and human studies have shown levobupivacaine to be less neuro- and cardiotoxic than racemic bupivacaine. The maximum dose of levobupivacaine has yet to be decided, although caution would suggest that it should be the same as that recommended for bupivacaine, at 2 mg/kg.