LEVOBUPIVACAINE

Levobupivacaine is an enantiomer of the long-acting local anaesthetic bupivacaine, which, although currently the most widely used agent in s urgery and obstetrics, is associated with potentially fatal cardiotoxi city. Levobupivacaine 75 to 122 mg was less arrhythmogenic than the sa me dose range of bupivacaine in healthy volunteers. Its effects on the corrected QT interval were significantly weaker than those of bupivac aine, and it tended to have a weaker effect on QRS duration. The CNS d epressant effect of intravenous levobupivacaine 40 mg was less than th at of bupivacaine 40 mg in healthy volunteers, both in terms of the ma gnitude of the effect and the regions of the cortex affected. Clinical studies have demonstrated that epidural levobupivacaine produces a se nsory and motor block clinically similar to that of bupivacaine in pat ients requiring anaesthesia during surgery. However. the duration of s ensory block was significantly longer with levobupivacaine 0.75% than with levobupivacaine 0.5% or bupivacaine 0.5% or 0.75% in one study. L evobupivacaine 0.25% was as effective as bupivacaine 0.25% in women re quiring epidural anaesthesia during labour with respect to time to ons et of pain relief, overall quality of analgesia, extent of sensory blo ckade and number of patients reporting motor block. Levobupivacaine is as well tolerated as bupivacaine. In a clinical study involving 88 pa tients who received either drug, intraoperative hypotension was the mo st commonly reported adverse event with levobupivacaine and no serious arrhythmias occurred.