Bupivacaine

Mechanism :

Bupivacaine is a local anesthetic. Local anesthetics block the generation and the conduction of nerve impulses 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. It long acting local anaesthetic. It has a slow onset as compared to other local anesthetics hence is predominantly used as an epidural anesthetic.

Indication :

Anaesthesia

Contraindications :

Bupivacaine is contraindicated in obstetrical paracervical block anesthesia. Its use by this technique has resulted in fetal bradycardia and death. Bupivacaine is contraindicated in patients with a known hypersensitivity to it or to any local anesthetic agent of the amide type or to other components of bupivacaine solutions.

Dosing :

Use in children <12 years is not recommended; >12 years:

Same as adult dose.

Caudal block:

15-30 ml of 0.25% or 0.5%.

Epidural block:

10-20 ml of 0.25%-0.5%administered in 3-5 ml increments allowing sufficient time to detect any toxic manifestations of inadvertent intravenous or intrathecal administration.

Peripheral nerve block:

5 ml of 0.25% or 0.5%; Max: 400 mg/day.

Sympathetic nerve block:

20-50 ml of 0.25% (no epinephrine).

Local anaesthesia:

0.25% infiltrated locally. Max: 175 mg.

The dosage of bupivacaine will depend upon the site of injection and the procedure used.

Adverse Effect :

Hypersensitivity reactions, systemic adverse effects following accidental IV administration, anginal pain, anxiety, apprehension, blurred vision, bradycardia, cardiovascular collapse, cardiac arrhythmias, chills, confusion, dizziness, drowsiness, edema, headache, hypotension, hypoventilation, nausea, loss of consciousness, palpitations, respiratory arrest, shivering, seizures, status asthmaticus, tachycardia, tinnitus, tremors, vomiting.

Interaction :

Monoamine Oxidase Inhibitors or Tricyclic Antidepressants: May produce severe, prolonged hypertension.
Vasopressor drugs and of Ergot-Type Oxytocic drugs: Cause severe, persistent hypertension or cerebrovascular accidents.
Phenothiazines and Butyrophenones: May reduce or reverse the pressor effect of epinephrine.

Hepatic Dose :

Bupivacaine is metabolized by the liver. Use with caution in hepatic impairment. Adjustment in dosing may be needed.