ropivakaiini

Ropivakaiini, known in English as ropivacaine, is an amide-type local anesthetic used for regional anesthesia and postoperative analgesia. It is marketed as a single enantiomer (the S(-) form) and is available in various concentrations for different techniques, including epidural, intrathecal, and peripheral nerve blocks.

Mechanism of action and properties:

Ropivacaine produces anesthesia by reversibly blocking voltage-gated sodium channels in nerve membranes, preventing initiation and propagation of action potentials. At equivalent doses, it tends to produce sensory blockade with relatively less motor blockade than some other local anesthetics, which can facilitate postoperative mobilization and reduce motor impairment.

Indications and administration:

Ropivacaine is used for epidural anesthesia and analgesia, intrathecal anesthesia in select procedures, and a range of peripheral nerve blocks for intraoperative and postoperative pain control. It is also used in continuous infusion techniques for sustained regional analgesia, including labor analgesia in appropriate protocols. Dosing and concentration depend on the procedure, patient factors, and desired balance between sensory and motor effects.

Pharmacokinetics:

As an amide-type local anesthetic, ropivacaine is primarily metabolized in the liver with renal excretion of metabolites. Onset of action is typically within minutes for many nerve blocks, and the duration of sensory blockade ranges from several hours, depending on dose and technique. Continuous infusions can provide extended analgesia beyond a single-dose administration.

Safety considerations:

Systemic toxicity is dose-related and can involve central nervous system and cardiovascular symptoms, such as perioral numbness, tinnitus, dizziness, seizures, or arrhythmias. Ropivacaine generally has a lower risk of cardiotoxicity than racemic bupivacaine, but intravascular injection or rapid absorption remains dangerous. Safety measures include aspiration before injection, incremental dosing, appropriate patient monitoring, and adjustment for hepatic impairment or pregnancy when indicated.

See also: local anesthetics, bupivacaine, lidocaine.