PI-WIKI-PHARM-19 · Pharmacology · reviewed 2026-10-31
Pharmacology, Topical Anesthetics in Tattooing
Critical numbers
Conservative Cap, Applied Lidocaine5 mg/kg (intact skin); ~300 mg for 60 kg adult
Conservative Cap, Applied Prilocaine6 mg/kg; ~360 mg for 60 kg adult
Lidocaine Plasma Toxicity (CNS)>5 μg/mL (perioral numbness, metallic taste, tinnitus)
Lidocaine Plasma Toxicity (Cardiac)Roughly 10-20 μg/mL and above (seizures, arrhythmia, collapse)
Lidocaine pKa7.9 (~25% uncharged at pH 7.4)
EMLA Onset60-90 minutes under occlusion
EMLA Duration~2 hours after removal
Lidocaine/Tetracaine 7%/7% Onset30 minutes (peel formulation)
Dermal Absorption Rate RangeA few % on intact skin (EMLA: ~3-6%); far more on broken skin or mucosa
Mucosal AbsorptionFar faster than intact skin
Methemoglobinemia Risk (Prilocaine)o-toluidine metabolite, threshold >600 mg total dose
Lipid Rescue TherapyIntralipid 20%, 1.5 mL/kg bolus then 0.25 mL/kg/min infusion
Do not
- Dosing by intuition instead of calculation
- Applying cream then immediately starting
- Using unknown or unregulated products
- Occluding large areas for long sessions
- Reapplication during a long session without dose tracking
- Ignoring drug interactions
Applicable standards
- European Union & UK — Classification is national
- United States — FDA OTC Monograph
- ASEAN & Asia-Pacific — Thailand