Local Anaesthetic Pregnancy: B

Lidocaine (Topical — Burns/Wounds)

Brand names: EMLA, LMX4, Xylocaine Gel

Adult dose

Dose: EMLA 2.5 g under occlusion for 45–60 min (skin); Xylocaine gel 2% applied to wound/mucosa as needed

Route: topical

Frequency: as required (procedural use)

Max: Systemic dose EMLA: 60 g cream; Lidocaine gel: limit to 3–5 mg/kg systemic equivalent

Burns dressing changes: lidocaine-soaked gauze applied 20 min before procedure; EMLA under burns dressing for superficial burn debridement

Route: topical

Frequency: as required

Max: Weight-based: 0–3 months/up to 5 kg: max 1 g EMLA per 10 cm²; 3–12 months: max 2 g

Concentration: EMLA 25 mg/g lidocaine + 25 mg/g prilocaine; LMX4 40 mg/g lidocaine g cream/ml

EMLA in neonates/infants: methaemoglobinaemia risk from prilocaine; LMX4 (lidocaine only) safer in <3 months

Renal

No dose adjustment required for topical

Hepatic

Systemic absorption: use with caution in severe hepatic impairment

LAST (Local Anaesthetic Systemic Toxicity): risk increases with extensive burns — monitor for circumoral tingling, tinnitus, altered taste
Burns dressing changes: most painful time is removal — lidocaine gel on dressing before removal reduces pain significantly
LMX4 preferred over EMLA for neonates — no prilocaine, so no methaemoglobinaemia risk

Local reactions (blanching, erythema)
Systemic toxicity if large area (CNS excitation → seizures → depression, cardiovascular collapse)
Methaemoglobinaemia (EMLA in young infants)

Antiarrhythmic drugs class III (additive cardiac effects if systemic absorption)
MAOIs

Reference: BNFc; BNF 86; BBA (British Burns Association) guidelines. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators