This combination is used as a local anesthetic for infiltration anesthesia and nerve block procedures.

1% Injection: Each mL contains:

• Lidocaine Hydrochloride (anhydrous) USP 10 mg
• Epinephrine (Adrenaline) USP 5 mcg

2% Injection: Each mL contains:

• Lidocaine Hydrochloride (anhydrous) USP 20 mg
• Epinephrine (Adrenaline) USP 5 mcg

This preparation is a sterile aqueous solution containing lidocaine hydrochloride along with epinephrine (adrenaline). Lidocaine is an amide-type local anesthetic that works by stabilizing neuronal membranes and blocking the ionic movements required for the initiation and transmission of nerve impulses, thereby producing a numbing effect. It has a rapid onset and a moderate duration of action. The addition of epinephrine, a vasoconstrictor, enhances the onset and prolongs the duration of anesthesia by reducing blood flow at the injection site and slowing systemic absorption. The anesthetic effect typically lasts about 1.5 to 2 hours when combined with epinephrine.

In estimating the safe dosage of this drug, it is important to take account of the rate at which it is absorbed and excreted as well as its potency. The patient's age, weight, physique and clinical condition, the degree of vascularity of the area to which the drug is to be applied, and the duration of administration are other factors which must be taken into account. The dosage is adjusted according to the response of the patient and site of administration. The lowest concentration and smallest dose producing the required effect should be given.

Adults: For healthy adults, the individual maximum recommended dose should not exceed 7 mg/kg of body weight and in general it is recommended that the maximum total dose not exceed 500 mg.

Children and elderly or debilitated patients: require smaller doses, commensurate with age and physical condition. Dosages in children should be reduced, commensurate with age, body-weight and physical condition.

The following doses have been recommended for individual local anaesthetic procedures in the USA:

• For percutaneous infiltration anaesthesia: 5 to 300 mg (1 to 60 mL of a 0.5% solution or 0.5 to 30 mL of a 1% solution).
• The dosage in peripheral nerve block depends on the route of administration. For brachial plexus block 225 to 300 mg (15 to 20 mL) as a 1.5% solution is used; for intercostal nerve block 30 mg (3 mL) is given as a 1% solution; for paracervical block a 1% solution is used in a dose of 100 mg (10 mL) on each side, repeated not more frequently than every 90 minutes; for paravertebral block a 1% solution may be used in doses of 30 to 50 mg (3 to 5 mL); a 1% solution is recommended for pudendal block in doses of 100 mg (10 mL) on each side; for retrobulbar block a 4% solution may be used in doses of 120 to 200 mg (3 to 5 mL).
• For sympathetic nerve block a 1% solution is recommended; doses are 50 mg (5 mL) for cervical block and 50 to 100 mg (5 to 10 mL) for lumbar block.
• For epidural anaesthesia 2 to 3 mL of solution is needed for each dermatome to be anaesthetised but usual total doses and recommended concentrations are: lumbar epidural 250 to 300 mg (25 to 30 mL) as a 1% solution for analgesia and 225 to 300 mg (15 to 20 mL) as a 1.5% solution or 200 to 300 mg (10 to 15 mL) as a 2% solution for anaesthesia, and for thoracic epidural a 1% solution may be used at doses of 200 to 300 mg (20 to 30 mL). In obstetric caudal analgesia 200 to 300 mg (20 to 30 mL) is used as a 1% solution and in surgical caudal anaesthesia a 1.5% solution may be used in doses of 225 to 300 mg (15 to 20 mL). For continuous epidural anaesthesia, the maximum doses should not be repeated more frequently than every 90 minutes.
• A hyperbaric solution of 1.5% or 5% lidocaine hydrochloride in glucose 7.5% solution is available for spinal anaesthesia; then epinephrine (adrenaline) should not be used. Doses of up to 50 mg (1 mL) as a 5% solution and 9 to 15 mg (0.6 to 1 mL) as a 1.5% solution have been used during labour for a normal vaginal delivery. Up to 75 mg (1.5 mL) as the 5% solution has been used for caesarean section and 75 to 100 mg (1.5 to 2 mL) for other surgical procedures.

Lidocaine with epinephrine may interact with monoamine oxidase inhibitors (MAOIs), tricyclic antidepressants, phenothiazines, butyrophenones, vasopressor agents, and ergot-type oxytocic drugs. These interactions may alter cardiovascular responses and should be considered during co-administration.

This combination is contraindicated in patients with known hypersensitivity to amide-type local anesthetics. It should not be injected into areas supplied by end arteries such as fingers, toes, ears, nose, or penis, as the vasoconstrictive effect of epinephrine may lead to tissue ischemia or gangrene.

It should also be avoided in patients where adrenergic stimulation is not desirable due to systemic absorption of epinephrine.

As with other local anaesthetics, adverse reactions are uncommon and are generally associated with elevated blood concentrations caused by accidental intravascular injection, excessive dosage, rapid absorption, or occasionally hypersensitivity, idiosyncratic response, or reduced patient tolerance. Under such conditions, systemic effects may involve the central nervous system (CNS) and/or the cardiovascular system. CNS effects may be excitatory or depressant, presenting with symptoms such as nervousness, dizziness, blurred vision, and tremors, which may progress to drowsiness, seizures, unconsciousness, and potentially respiratory arrest. The excitatory phase may be brief or absent, with drowsiness appearing as the initial sign, progressing directly to unconsciousness and respiratory arrest. Cardiovascular effects may include hypotension, myocardial depression, bradycardia, and in severe cases, cardiac arrest. Allergic reactions are extremely rare and may present as skin lesions, urticaria, oedema, or anaphylactoid reactions.

Although animal studies have not shown evidence of harm to the foetus, as with all medications, it should not be used during early pregnancy unless the expected benefits outweigh the potential risks. It is not known whether this drug is excreted in human breast milk. Since many drugs are excreted in breast milk, caution should be exercised when administering to breastfeeding women.

This injection for infiltration and nerve block should be administered only by clinicians experienced in the diagnosis and management of dose-related toxicity. The safety and effectiveness of lidocaine depend on appropriate dosage, correct administration technique, necessary precautions, and preparedness for emergencies. Standard medical references should be consulted for specific techniques and precautions related to various regional anaesthetic procedures. Resuscitation equipment, oxygen, and emergency medications should be readily available for immediate use. It should be used cautiously in patients with epilepsy, impaired cardiac conduction, impaired respiratory function, and hepatic impairment, particularly when the dose or site of administration may lead to high blood concentrations. The lowest effective dose should be used to minimize high plasma levels and serious adverse effects. The effectiveness of local anaesthetics may be reduced when injected into inflamed or infected tissues. Caution is also advised in patients with hypertension, cardiac disease, cerebrovascular insufficiency, thyrotoxicosis, and in those receiving tricyclic antidepressants, monoamine oxidase inhibitors (MAOIs), or potent general anaesthetic agents. Continuous and careful monitoring of cardiovascular and respiratory vital signs, as well as the patient’s level of consciousness, should be maintained after each local anaesthetic injection.

Local and surface anesthetic

Store below 30°C in a dry place, protected from light and moisture. Keep out of reach of children.