Lidocaina Cloridrato S.A.L.F. (Lidocaine Hydrochloride Monohydrate)

Lidocaine is a local anesthetic used to block nerve conduction in various clinical settings.

• Minor surgical or dental procedures: provides local anesthesia to reduce pain during the procedure.
• Infiltration anesthesia: produces numbness in targeted tissue for minor interventions.
• Nerve block: achieves regional anesthesia for specific nerve territories.
• Intravenous regional anesthesia (Bier block): enables temporary limb anesthesia for short surgeries.
• Antiarrhythmic therapy (IV use): stabilizes cardiac rhythm in certain arrhythmias.

• Lidocaine reversibly binds to voltage‑gated sodium channels on neuronal membranes, stabilizing the inactive state of the channel. This blocks sodium influx, preventing depolarization and propagation of nerve impulses, which results in loss of sensation in the treated area and, when administered intravenously, can suppress abnormal cardiac conduction.

Lidocaine may cause a range of adverse reactions, from mild to severe.

Common Side Effects

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

Serious or Rare Side Effects

• Methemoglobinemia
• Cardiac arrhythmias or conduction block
• Seizures or central nervous system toxicity
• Allergic reactions including anaphylaxis
• Respiratory depression
• Severe hypotension or cardiovascular collapse

Before using lidocaine, consider the following safety measures.

• Allergy assessment: verify no known hypersensitivity to amide‑type local anesthetics.
• Cardiac monitoring: observe patients with pre‑existing heart disease or conduction abnormalities.
• Dose limitation: avoid exceeding recommended maximum doses, especially with repeated infiltrations.
• Concurrent medications: review use of other sodium channel blockers or CYP inhibitors.
• Pediatric and geriatric use: adjust dosing and monitor closely in vulnerable populations.
• Store below 25°C: keep in the original container, protect from light and moisture.

Lidocaine can interact with several drugs, requiring caution.

Major Interactions (Avoid)

• Class I antiarrhythmics (e.g., quinidine): may increase plasma lidocaine levels.
• Strong CYP3A4 inhibitors (e.g., ketoconazole): can raise concentrations and toxicity risk.
• Beta‑adrenergic blockers (e.g., propranolol): may enhance cardiotoxic effects.
• Concurrent use of other local anesthetics: additive toxicity.
• Methylene blue: may precipitate methemoglobinemia.

Moderate Interactions (Monitor Closely)

• CYP1A2 inducers (e.g., carbamazepine): may reduce lidocaine efficacy.
• Diuretics (e.g., furosemide): can alter plasma protein binding.
• General anesthetics (e.g., propofol): may potentiate central nervous system depression.
• Anticonvulsants (e.g., phenytoin): may affect seizure threshold.
• Alcohol consumption: can increase CNS depressive effects.