Levobupivacaine

Levobupivacaine is an enantiomer of the long-acting local anaesthetic bupivacaine, which, although currently the most widely used agent in surgery and obstetrics, is associated with potentially fatal cardiotoxicity. Levobupivacaine 75 to 122 mg was less arrhythmogenic than the same dose range of bupivacaine in healthy volunteers. Its effects on the corrected QT interval were significantly weaker than those of bupivacaine, and it tended to have a weaker effect on QRS duration. The CNS depressant effect of intravenous levobupivacaine 40 mg was less than that of bupivacaine 40 mg in healthy volunteers, both in terms of the magnitude of the effect and the regions of the cortex affected. Clinical studies have demonstrated that epidural levobupivacaine produces a sensory and motor block clinically similar to that of bupivacaine in patients requiring anaesthesia during surgery. However, the duration of sensory block was significantly longer with levobupivacaine 0.75% than with levobupivacaine 0.5% or bupivacaine 0.5% or 0.75% in one study. Levobupivacaine 0.25% was as effective as bupivacaine 0.25% in women requiring epidural anaesthesia during labour with respect to time to onset of pain relief, overall quality of analgesia, extent of sensory blockade and number of patients reporting motor block. Levobupivacaine is as well tolerated as bupivacaine. In a clinical study involving 88 patients who received either drug, intraoperative hypotension was the most commonly reported adverse event with levobupivacaine and no serious arrhythmias occurred.