BUPIVACAINE 5MG/ML INJECTION

Indications

• Regional anesthesia for surgical procedures
• Pain management in obstetric settings (e.g., epidural analgesia during labor)
• Postoperative analgesia
• Nerve blocks for pain control

Dosage

Children: Refer to the BNF for Children for specific dosing information in paediatric patients.

Adults: For infiltration anesthesia, the typical dose is 5 to 10 mL of a 0.25% to 0.5% solution. For epidural anesthesia, a dose of 10 to 20 mL of a 0.25% to 0.5% solution may be used, depending on the procedure.

Mechanism of action

Bupivacaine acts by inhibiting voltage-gated sodium channels in the neuronal cell membrane. This inhibition prevents the initiation and propagation of action potentials, leading to a reversible loss of sensation in the area supplied by the affected nerves. It predominantly affects small unmyelinated fibers, which are responsible for pain and temperature sensation.

Pharmacodynamics

The onset of action for bupivacaine is dose-dependent, with effects typically observed within 10 to 30 minutes after administration, depending on the route of administration. The duration of action can last from 2 to 8 hours, with longer durations noted for higher doses or when used in conjunction with vasoconstrictors. Bupivacaine is more potent than lidocaine and provides a longer duration of anesthesia.

Pharmacokinetics

Bupivacaine is well-absorbed after injection, with peak plasma concentrations occurring within 30 minutes. It is metabolized primarily in the liver by cytochrome P450 enzymes, and its metabolites are excreted in the urine. The elimination half-life ranges from 2.5 to 6 hours, depending on the route of administration and patient-specific factors.

Contra-indications

• Hypersensitivity to bupivacaine or any component of the formulation
• Severe heart block
• Severe hepatic impairment
• Uncontrolled hypotension

Adverse effects

• Cardiovascular collapse
• Hypotension
• Bradycardia
• Nausea
• Vomiting
• Dizziness
• Headache
• Numbness
• Paresthesia
• Tremors

Interactions

• Concurrent use with other local anesthetics may increase the risk of toxicity
• Caution advised when used with agents that can affect the cardiovascular system

Precautions

• Use with caution in patients with cardiovascular disease
• Monitor for signs of systemic toxicity, particularly in high doses or accidental intravascular injection
• Ensure resuscitation equipment and trained personnel are available during administration

Pregnancy

Bupivacaine can be used during pregnancy when the potential benefits justify the risks. Consult relevant clinical guidelines.

Breast-feeding

Bupivacaine is excreted in breast milk. Caution is advised when administering to nursing mothers.

Storage

Store at room temperature, away from light and moisture. Do not freeze.

Formulations

• Injection solution
• Epidural solution
• Nerve block solution

Indications

• Infiltration anaesthesia in dentistry
• Nerve blocks for surgery
• Epidural anaesthesia
• Post-operative pain management

Dosage

Adults: Bolus doses of 1.5 mL/kg over 1 minute, with intervals of 5 minutes, and maximum cumulative doses should not exceed 12 mL/kg. For continuous infusion, the rate may

Mechanism of action

Bupivacaine hydrochloride acts by blocking voltage-gated sodium channels on the neuronal cell membrane, which inhibits the influx of sodium ions, leading to a decrease in depolarization and action potential generation. This mechanism results in reversible loss of sensation in the targeted area. The effect is dose-dependent and varies based on the route of administration.

Pharmacodynamics

Bupivacaine exhibits a high lipid solubility, which facilitates its action at the nerve membrane. The onset of action is typically within 10 to 20 minutes, with a duration of effect that can last from 2 to 8 hours, depending on the dosage and the method of administration. The drug provides effective analgesia, making it a preferred choice for procedures requiring prolonged pain relief. However, caution is advised as high concentrations can lead to systemic toxicity, primarily affecting the central nervous and cardiovascular systems.

Pharmacokinetics

Bupivacaine is rapidly absorbed following parenteral administration, with peak plasma concentrations occurring within 30 minutes to 2 hours. The drug is extensively metabolized in the liver by cytochrome P450 enzymes and excreted in the urine as metabolites. Its half-life ranges from 2.5 to 6 hours in healthy individuals, but it can be prolonged in patients with hepatic impairment. Due to its extensive protein binding (approximately 95%), the free fraction available for action is reduced in conditions affecting protein levels.

Contra-indications

• Hypersensitivity to bupivacaine or any of its components
• Application to damaged skin
• Severe hypertension
• Unstable cardiac rhythm

Adverse effects

• Face oedema
• Gingivitis
• Headache
• Nausea
• Abnormal sensation

Interactions

• Concurrent use of sympathomimetics may increase cardiovascular effects
• Adrenaline should be used with caution; total dose should not exceed 5 micrograms/kg
• Avoid using propofol as an alternative to lipid emulsion treatment

Precautions

• Use with caution in patients with hepatic impairment due to increased risk of toxicity
• Use with caution in patients with renal impairment
• Requires monitoring of blood pressure and ECG during administration
• Should only be administered by trained personnel experienced in its use

Pregnancy

Use only if potential benefit outweighs risk; no information available.

Breast-feeding

Avoid breastfeeding for 48 hours after administration.

Storage

Store at room temperature, away from light. Do not freeze.

Formulations

• Solution for injection cartridges
• Injectable preparation