Usage
- Medical Conditions: This combination is primarily used for local anesthesia, providing pain relief and vasoconstriction (narrowing of blood vessels) during minor surgical procedures, dental work, and other interventions. It is also employed to prolong the anesthetic effects of Lidocaine.
- Pharmacological Classification: Local anesthetic (Lidocaine), vasoconstrictor (Adrenaline), and antimicrobial preservative (Methylparaben).
- Mechanism of Action: Lidocaine blocks nerve impulses, preventing pain signals from reaching the brain. Adrenaline constricts blood vessels, reducing bleeding and prolonging Lidocaine’s action by slowing its absorption. Methylparaben acts as a preservative to inhibit microbial growth in multi-dose vials.
Alternate Names
- Alternate Names: Lidocaine with Epinephrine and Methylparaben, Lidocaine-Adrenaline combination, Lignocaine and Adrenaline Injection BP
- Brand Names: Xylocaine with Epinephrine, Lox 2% Adr, Akason Lidocaine with Adrenaline
How It Works
- Pharmacodynamics: Lidocaine reversibly binds to sodium channels in nerve fibers, blocking nerve impulse transmission. Adrenaline stimulates alpha-adrenergic receptors, causing vasoconstriction.
- Pharmacokinetics: Lidocaine is absorbed rapidly after injection, metabolized by the liver (primarily through CYP enzymes), and eliminated renally. Adrenaline is metabolized by COMT and MAO enzymes and excreted in the urine.
- Mode of Action: Lidocaine blocks sodium channels, inhibiting depolarization and preventing action potential propagation. Adrenaline acts on alpha-adrenergic receptors in blood vessels, causing smooth muscle contraction and vasoconstriction.
- Elimination Pathways: Lidocaine is primarily metabolized in the liver and excreted in the urine. Adrenaline is metabolized by both hepatic and extrahepatic mechanisms and excreted renally.
Dosage
Standard Dosage
Adults:
- The dosage is determined by the area being anesthetized and the desired level of anesthesia.
- The maximum recommended single dose of Lidocaine with Adrenaline is 500mg (7mg/kg) for a 70 kg adult.
- Lower doses should be used for infiltration anesthesia compared to nerve blocks.
Children:
- Dosages in children should be reduced based on their age, weight, and physical condition.
- Use a weight-based calculation up to a maximum of 5 mg/kg without epinephrine or 7 mg/kg with epinephrine.
Special Cases:
- Elderly Patients: Reduced doses are recommended due to age-related physiological changes like decreased liver and kidney function.
- Patients with Renal Impairment: Dose adjustments may be necessary, based on the degree of impairment.
- Patients with Hepatic Dysfunction: Dose reduction is essential due to decreased Lidocaine metabolism.
- Patients with Comorbid Conditions: Exercise caution in patients with cardiovascular disease, hypertension, hyperthyroidism, and epilepsy.
Clinical Use Cases:
- Intubation: Lidocaine 4% solution for topical anesthesia.
- Surgical Procedures: Infiltration or nerve blocks with Lidocaine 0.5%-2% with Adrenaline.
- Mechanical Ventilation: Not typically used in this context.
- Intensive Care Unit (ICU) Use: Limited to specific situations for local anesthesia.
- Emergency Situations: Lidocaine without Adrenaline can be used for certain cardiac arrhythmias.
Side Effects
Common Side Effects:
- Pain, burning, or stinging at the injection site.
- Pale skin, itching, redness, or small red spots (petechiae).
- Anxiety, nervousness, dizziness, lightheadedness, or blurred vision.
Rare but Serious Side Effects:
- Allergic reactions (cutaneous lesions, urticaria, edema, anaphylaxis).
- Seizures, respiratory depression, cardiac arrest, cardiovascular collapse.
Contraindications:
- Hypersensitivity to amide-type local anesthetics, adrenaline, methylparaben, or any components of the formulation.
- Use in areas with compromised blood supply (e.g., fingers, toes, ears, nose, penis).
- Intravenous or intrathecal administration of formulations containing methylparaben.
- Patients with severe cardiovascular disease, untreated hyperthyroidism, narrow-angle glaucoma, or pheochromocytoma.
Drug Interactions:
- Beta-blockers, MAO inhibitors, tricyclic antidepressants may potentiate the effects of Adrenaline.
- Halogenated inhalational anesthetics may increase the risk of cardiac arrhythmias with Adrenaline.
- Certain antihistamines and thyroid hormones may enhance Adrenaline’s effects.
Pregnancy and Breastfeeding:
- Pregnancy Safety Category: C (FDA). Although animal studies haven’t shown fetal harm, there are no adequate studies in pregnant women. Use only if potential benefits outweigh the risks.
- Breastfeeding: Lidocaine is excreted in breast milk. Adrenaline is not expected to have adverse effects on the infant. Caution is advised.
Drug Profile Summary
- Mechanism of Action: Lidocaine blocks sodium channels, inhibiting nerve conduction. Adrenaline causes vasoconstriction.
- Side Effects: Common: pain, burning at the injection site; Rare: allergic reactions, seizures, cardiac arrest.
- Contraindications: Hypersensitivity, compromised blood supply to injection area, intravenous use.
- Drug Interactions: Beta-blockers, MAOIs, tricyclic antidepressants, halogenated anesthetics.
- Pregnancy & Breastfeeding: Use with caution. Category C.
- Dosage: Varies by procedure, generally up to 500 mg with adrenaline in adults.
- Monitoring Parameters: Vital signs, ECG, respiratory function, level of consciousness.
Popular Combinations
- Lidocaine and Adrenaline are commonly combined. The addition of Adrenaline prolongs Lidocaine’s anesthetic action and reduces bleeding.
Precautions:
- Aspirate before injection to avoid intravascular administration.
- Monitor vital signs and be prepared to manage adverse reactions.
- Avoid use in patients with certain medical conditions (see Contraindications).
- Use caution in pregnant and breastfeeding women.
- Children and elderly patients may require dose adjustments.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Adrenaline + Lidocaine + Methylparaben?
A: The dosage depends on the procedure and the patient. Refer to the Dosage section for details.
Q2: Can this combination be used during pregnancy?
A: It is a Pregnancy Category C drug. Use only if the benefits outweigh the risks.
Q3: Are there any serious side effects?
A: Yes, rare but serious side effects include allergic reactions, seizures, and cardiac arrest.
Q4: What are the contraindications for this combination?
A: Hypersensitivity, areas of compromised blood supply, intravenous use, and certain medical conditions.
Q5: How does adrenaline affect lidocaine’s action?
A: Adrenaline prolongs lidocaine’s anesthetic effects and reduces bleeding.
Q6: Can this combination be used for spinal anesthesia?
A: Formulations containing methylparaben should not be used for spinal or epidural anesthesia.
Q7: What are the common side effects?
A: Pain or burning at the injection site, pale skin, dizziness, blurred vision.
Q8: What should I do if a patient experiences an allergic reaction?
A: Discontinue the drug immediately and manage the reaction with appropriate measures (e.g., antihistamines, corticosteroids, epinephrine).
A: Lidocaine is primarily metabolized by the liver, involving CYP enzymes.
Q10: Is it safe to use this combination in patients with cardiovascular disease?
A: Use caution in patients with cardiovascular disease and monitor closely. Certain severe cardiovascular conditions are contraindications.
