Lidocaine
Lidocaine hydrochloride
Brand names:Xylocaine, LMX, Lidoderm
An amide local anesthetic that blocks sodium channels in nerves and cardiac tissue. In EMS, lidocaine is used for local anesthesia (wound care, IO needle placement pain), as a Class IB antiarrhythmic for ventricular dysrhythmias, and to reduce pain from IM ceftriaxone reconstitution in TCCC protocols.
Pharmacology and Actions
Lidocaine reversibly blocks voltage-gated sodium channels, preventing depolarization in nerves (producing local anesthesia) and in cardiac tissue (producing antiarrhythmic effects on ventricular myocardium and Purkinje fibers). The drug does not affect atrial tissue significantly, which is why it is selective for ventricular arrhythmias. Onset is rapid; duration depends on route, concentration, and presence of epinephrine in the formulation.
Indications
- Local anesthesia for wound closure, laceration repair, IO needle placement
- Reconstitution diluent for IM ceftriaxone (TCCC; reduces injection pain)
- Ventricular tachycardia or ventricular fibrillation refractory to defibrillation (alternative to amiodarone)
- Premature ventricular contractions causing hemodynamic compromise
- Topical anesthesia for mucosal procedures (lidocaine gel, viscous lidocaine)
Absolute Contraindications
- Known lidocaine or amide local anesthetic allergy
- Severe heart block (second or third degree) without pacing
- Wolff-Parkinson-White syndrome with atrial fibrillation
- Stokes-Adams syndrome
- Severe sinoatrial, atrioventricular, or intraventricular conduction blocks
Precautions and Side Effects
Systemic toxicity (LAST: local anesthetic systemic toxicity) presents as perioral numbness, metallic taste, tinnitus, confusion, seizures, and cardiac arrest. Toxicity is dose-dependent and occurs at plasma concentrations above 5 mcg/mL. Avoid inadvertent intravascular injection during local infiltration by aspirating before injection. Lidocaine with epinephrine should not be used on digits, ears, nose, or penis due to vasoconstriction risk. Caution in hepatic impairment, congestive heart failure, and elderly patients.
Adult Dosing
Pediatric Dosing
Ventricular arrhythmia pediatric: 1 mg/kg IV/IO bolus. May repeat 0.5 mg/kg every 5 to 10 minutes, maximum 3 mg/kg total. Local anesthesia maximum 4.5 mg/kg without epinephrine.
Pharmacokinetics
Peak Effect: IV: 45 to 90 seconds. Local infiltration: 2 to 5 minutes.
Duration: IV: 10 to 20 minutes. Local infiltration: 30 minutes to 2 hours (longer with epinephrine).
Storage and Handling
Store at controlled room temperature (15 to 30 degrees Celsius). Protect from light. Lidocaine with epinephrine has additional storage requirements; do not freeze and protect from extreme heat. Discoloration indicates degradation.
Reconstitution:
Lidocaine is supplied as a sterile solution in multiple concentrations: 0.5 percent, 1 percent, 2 percent, 4 percent, and others. For TCCC ceftriaxone reconstitution, use 1 percent preservative-free lidocaine. For local infiltration, choose concentration based on volume and area to be anesthetized. No reconstitution required for ready-to-use formulations.
TCCC and TECC Role
Lidocaine has two distinct TCCC roles. First, as a reconstitution diluent for IM ceftriaxone (1 percent preservative-free lidocaine), which significantly reduces the pain of IM injection in casualties receiving wound prophylaxis. Second, as a local anesthetic for procedural pain (laceration repair, IO needle insertion in conscious casualties, wound debridement). The antiarrhythmic use of lidocaine is part of standard ACLS but is rarely a tactical environment concern.
Lidocaine is the drug that makes invasive procedures bearable for awake casualties. Reconstituting IM ceftriaxone with 1 percent lidocaine instead of sterile water transforms a memorably painful 2 gram injection into a tolerable one. IO needles in conscious patients without lidocaine are excruciating; 40 mg of 2 percent preservative-free lidocaine pushed slowly before the flush takes the edge off. Local infiltration for laceration repair lets you do the procedure right without rushing through the casualty's pain.
Using preservative-containing lidocaine (the standard multi-dose vial) for IO pain reduction or intrathecal use. The methylparaben preservative is locally irritating and can cause complications. Always use preservative-free lidocaine for IO needle pain reduction and any spinal or epidural use. Multi-dose vials with preservative are appropriate for local infiltration and topical use.
This drug profile is provided as educational reference material for trained medical providers. It is not medical advice, not a substitute for formal training, and not a substitute for current published guidelines or medical direction.
Drug administration is governed by your scope of practice, agency standing orders, medical director protocols, and applicable state and federal regulations. Controlled substances are subject to additional handling, accountability, and documentation requirements per DEA and state law. Always verify dosing, indications, contraindications, and route of administration against current published guidelines and your local protocols before administration.
If this content is being viewed during a medical emergency, call 911 immediately and follow the direction of your local emergency dispatch and medical control. Do not use this reference as a substitute for emergency medical services.
Drug information evolves. Last reviewed dates and source citations are provided for each entry. Confirm currency against the cited source before clinical use.
Penn Tactical Solutions publishes this reference for educational purposes. PTS does not provide medical direction and does not assume responsibility for clinical decisions made in the field. Clinical responsibility rests with the administering provider, their medical director, and their agency.
Educational reference for trained medical providers. Not medical advice. Not a substitute for formal training, current published guidelines, or medical direction. Drug administration is governed by your scope of practice, agency standing orders, medical director protocols, and applicable state and federal regulations. Controlled substances require additional storage, accountability, and documentation per DEA and state law.
In a medical emergency, call 911. This reference is not a substitute for emergency medical services.
Verify dosing, indications, and contraindications against current published guidelines and your local protocols before administration. Confirm content currency against the source citation. Penn Tactical Solutions does not provide medical direction. Clinical responsibility rests with the administering provider, their medical director, and their agency.
Lidocaine
| IV/IO | Ventricular arrhythmia (refractory VF/VT): 1 to 1.5 mg/kg IV/IO bolus. May repeat 0.5 to 0.75 mg/kg every 5 to 10 minutes, maximum 3 mg/kg total. Maintenance infusion 1 to 4 mg/min after ROSC. (30 to 90 seconds (cardiac effect)) |
| PO | Viscous lidocaine 2 percent: 15 mL swish and swallow or swish and spit for oral mucosal pain. (Topical: 2 to 5 minutes for mucosal anesthesia) |