Ropivacaine

Mechanism :

Local anesthetics such as Ropivacaine block the generation and the conduction of nerve impulses, presumably by increasing the threshold for electrical excitation in the nerve, by slowing the propagation of the nerve impulse, and by reducing the rate of rise of the action potential. Specifically, they block the sodium-channel and decrease chances of depolarization and consequent action potentials. In general, the progression of anesthesia is related to the diameter, myelination and conduction velocity of affected nerve fibres.

Indication :

Obstetric anaesthesia
Regional anaesthesia

Contraindications :

Hypersensitivity to amide anesthetics, Infection at injection site, Intra-articular continuous infusion, PTS <12 yo.

Caution in elderly pts, acutely ill pts.

Caution if hepatic impairment, renal disease, impaired cardiac function, heart block, hypovolemia, hypotension.

Dosing :

Caudal Epidural Block (off-label):

1.25-6.5 mg/kg or 1 ml/kg of 0.2% strength

Epidural continuous infusion (off-label):

<4 months: Safety and efficacy not established

4 months-7 years: Loading dose of 1 mg/kg, followed by maintenance dose of 0.2-0.4 mg/kg/hour for 2 days.

7-12 years: Loading dose of 3.6 mg, followed by maintenance dose of 3.2 mg/hour infusion; dose may be titrated to 27.2 mg/hour as and when required.

>12 years: 75-2000 mg (15-30 ml of 0.5-1% of solution).

Adverse Effect :

Serious Reactions: CNS toxicity, myocardial depression, seizures, unconsciousness, respiratory arrest, heart block, hypotension, bradycardia, ventricular arrhythmias, cardiac arrest, anaphylactoid reaction.

Common Reactions: Hypotension, nausea/vomiting, paresthesia, pain, non-specific bradycardia, headache, fever, rigors, dizziness, injection site burning, pruritus, drowsiness, restlessness, anxiety, blurred vision, tinnitus.

Interaction :

Fluvoxamine: Increases the effect and toxicity of ropivacaine.

Hepatic Dose :

Dose reduction may be necessary as ropivacaine has extensive hepatic metabolism and plasma levels of the drug can increase with hepatic impairment.