Overview
Lidocaine is a local anesthetic that provides temporary relief of pain by blocking sodium channels in nerve fibers, preventing the initiation and conduction of nerve impulses. It is commonly used topically for localized pain management in various conditions.
Mechanism of Action
Lidocaine acts as a local anesthetic by blocking voltage-gated sodium channels in neuronal cell membranes, thereby inhibiting the initiation and propagation of action potentials and producing reversible loss of sensation in the affected area.
Indications
- Temporary relief of pain
- Local anesthesia for minor procedures
- Postherpetic neuralgia
- Neuropathic pain conditions
Common Doses
- 4% topical patch
- 2% cream/gel
- 5% ointment
- 1-2% injection solutions
Dosage
For topical patch: Apply to clean, dry affected area. Do not use more than one patch in a 12-hour period. Maximum 2 patches per day. Discard after single use. Children under 2 years: consult physician.
Contraindications
- Hypersensitivity to lidocaine or other local anesthetics
- Application to broken or inflamed skin
- Infection at application site
Side Effects
- Local skin reactions (redness, itching, burning)
- Rash
- Dizziness
- Nausea
- Methemoglobinemia (rare but serious)
Interactions
- Antiarrhythmic drugs (increased cardiac effects)
- Other local anesthetics (additive toxicity)
- CYP450 inhibitors (may increase lidocaine levels)
Counseling Points
- Apply only to intact skin
- Wash hands before and after application
- Do not cut or trim patches
- Remove patch if irritation occurs
- Store at room temperature
- Keep out of reach of children