Lidocaine hydrochloride (Xylocaine®)

Section 1.1

Midwives may independently prescribe, order and administer this drug.

Without epinephrine. Lidocaine is an amide-type local anaesthetic. Blocks the initiation and conduction of nerve impulses.

Indications and Clinical Use:

Used to anaesthetize the perineum and vaginal walls for repair of laceration or an emergency episiotomy.

Contraindications:

Hypersensitivity to lidocaine, amide type local anaesthetics (bupivacaine, mepivacaine, ropivacaine), or any component of the formulation.

Midwives are encouraged to consult with anaesthesia antenatally, in the event that a sensitivity or allergy to anaesthetic agents is suspected.

An allergy to lidocaine is unlikely when used without epinephrine. The concern is often an adverse drug reaction to the adrenaline (epinephrine) that is found in a combined lidocaine/epinephrine product. The epinephrine is added to constrict the blood vessels to help concentrate the local anaesthetic at the site where it is needed. If epinephrine enters the circulatory system, it can cause tachycardia. In an anxious person this could trigger a panic attack.

Warnings and Precautions:

Use with caution if there is hepatic dysfunction due to an increased risk of lidocaine toxicity.

Pregnancy:

Compatible

Lactation:

Category L2 – Limited Human Data – Probably Compatible

Adverse Reactions:

Hypotension, anxiety, dizziness, nausea, vomiting, dyspnea, allergic reactions and anaphylaxis.

Dosage and Administration:

Usual concentration: 1% (10 mg per mL). Maximum individual dose should not exceed 4.5 mg/kg of body weight and in general the maximum total dose should not exceed 300 mg or 30 mL.

Subcutaneous administration is the route of choice – only the lowest dose needed to provide effective anaesthesia should be administered. Injections should always be made slowly and with frequent aspirations to avoid inadvertent rapid intravascular administration which can produce increased systemic absorption and toxicity.

Onset of Action:

5-10 minutes

Half-life:

1.5-2 hours

Elimination:

Urine (<10% as unchanged drug, ~90% as metabolites)