Ropivacaine.

Ropivacaine (Naropin, AstraZeneca) is a long-acting amide local anaesthetic released for clinical use in 1996. Similar to bupivacaine, ropivacaine is equally effective for s.c. infiltration, epidural and peripheral nerve block for surgery, obstetric and post-operative analgesia. Ropivacaine differs from most other amide-type local anaesthetics in that it is marketed as a pure S-enantiomer, instead of as a racemate. This feature improves the safety of ropivacaine, and, indeed, studies have shown ropivacaine to have less cardiovascular and CNS toxicity than bupivacaine. Ropivacaine is nearly identical to bupivacaine in onset, quality and duration of sensory block, but it produces less motor block. Whether or not the motor sparing effect of ropivacaine is due to a lower relative potency compared to bupivacaine is a matter of intense debate. Despite a better safety profile, the increased cost of ropivacaine may limit its clinical utility.