Mesocaine (Lidocaine Hydrochloride)

Mesocaine (lidocaine) is used in the cardiovascular and local anesthetic pathways to treat specific arrhythmias and provide procedural analgesia.

• Ventricular arrhythmias: stabilizes cardiac rhythm and reduces ectopic activity.
• Cardiac arrhythmias (general): assists in controlling abnormal heart rhythms during emergency treatment.
• Local anesthesia for minor surgical or diagnostic procedures: provides rapid, reversible loss of sensation at the targeted site.

• Lidocaine blocks voltage‑gated sodium channels on neuronal and cardiac cell membranes, decreasing the influx of sodium ions during depolarization. This stabilizes the membrane, prevents initiation and propagation of nerve impulses, and reduces automaticity in cardiac tissue, thereby producing local anesthetic and antiarrhythmic effects.

Common Side Effects

• Tingling or numbness at the injection site.
• Dizziness or light‑headedness.
• Metallic taste in the mouth.
• Nausea or mild vomiting.
• Transient hypotension.
• Mild bradycardia.

Serious or Rare Side Effects

• Severe allergic reaction (anaphylaxis) with rash, swelling, or airway compromise.
• Cardiac arrest or severe arrhythmia worsening.
• Seizures or generalized convulsions.
• Profound hypotension leading to shock.
• Methemoglobinemia causing cyanosis.
• Persistent neurological deficits.

Before administering Mesocaine, consider the following precautions:

• Cardiovascular monitoring: observe for bradycardia, hypotension, or arrhythmia changes.
• Central nervous system monitoring: watch for tinnitus, visual disturbances, or signs of toxicity.
• Hepatic impairment: dose adjustment may be required due to reduced metabolism.
• Known lidocaine allergy: avoid use in patients with documented hypersensitivity.
• Pregnancy and lactation: use only if the potential benefit justifies the potential risk.
• Store at room temperature: keep in the original container, protect from light and moisture.

When using Mesocaine, be aware of drug interactions that may alter its safety profile.

Major Interactions (Avoid)

• Class I antiarrhythmics (e.g., quinidine): increased risk of lidocaine toxicity.
• Beta‑blockers (e.g., propranolol): may exacerbate bradycardia and hypotension.
• Strong CYP3A4 inhibitors (e.g., ketoconazole): elevate plasma lidocaine concentrations.

Moderate Interactions (Monitor Closely)

• Class III antiarrhythmics (e.g., amiodarone): additive cardiac conduction effects.
• Calcium channel blockers (e.g., verapamil): may affect heart rate and contractility.
• Concurrent use of other local anesthetics: risk of cumulative systemic toxicity.