Ropivacaine

Ropivacaine (rINN) is a local anaesthetic drug belonging to the amino amide group. The name ropivacaine refers to both the racemate and the marketed S-enantiomer. Ropivacaine hydrochloride is commonly marketed by AstraZeneca under the trade name Naropin.

History
Ropivacaine was developed after bupivacaine was noted to be associated with cardiac arrest, particularly in pregnant women. Ropivacaine was found to have less cardiotoxicity than bupivacaine in animal models.

Indications
Ropivacaine is indicated for local anaesthesia including infiltration, nerve block, epidural and intrathecal anaesthesia in adults and children over 12 years. It is also indicated for peripheral nerve block and caudal epidural in children 1–12 years for surgical pain. It is also sometimes used for infiltration anaesthesia for surgical pain in children.

Ropivacaine is often co-administered with fentanyl for epidural analgesia, for example in pregnant women during labour.

Contraindications
Ropivacaine is contraindicated for IV regional anaesthesia (IVRA). However, new data suggested that both Ropivacaine (1.2-1.8mg/kg in 40ml) and levobupivacaine (40ml of 0.125% solution) can be used, because they have less cardiovascular and central nervous system toxicity than racemic bupivacaine (Basic of Anesthesia, Robert Stoelting, page 289).

Adverse effects
Adverse drug reactions (ADRs) are rare when it is administered correctly. Most ADRs relate to administration technique (resulting in systemic exposure) or pharmacological effects of anesthesia, however allergic reactions can rarely occur.

Systemic exposure to excessive quantities of ropivacaine mainly result in central nervous system (CNS) and cardiovascular effects – CNS effects usually occur at lower blood plasma concentrations and additional cardiovascular effects present at higher concentrations, though cardiovascular collapse may also occur with low concentrations. CNS effects may include CNS excitation (nervousness, tingling around the mouth, tinnitus, tremor, dizziness, blurred vision, seizures) followed by depression (drowsiness, loss of consciousness, respiratory depression and apnea). Cardiovascular effects include hypotension, bradycardia, arrhythmias, and/or cardiac arrest – some of which may be due to hypoxemia secondary to respiratory depression.

Treatment of overdose: "Lipid rescue"
As for bupivacaine, there is evidence that Intralipid, a commonly available intravenous lipid emulsion, can be effective in treating severe cardiotoxicity secondary to local anaesthetic overdose in animal experiments and in humans.