Hygiene Atlas

Atlas · Plate VIII · Pharmacology and Local Anesthesia · 09

Local anesthetic doses

Milligrams per cartridge equal the percentage times 10 times the volume, so a 1.8 mL cartridge of 2% holds 36 mg. Multiply the mg/kg maximum by the weight in kilograms, check the absolute cap, then divide by the mg per cartridge. Lidocaine with epinephrine allows 7.0 mg/kg up to 500 mg. Early overdose signs include talkativeness, slurred speech, tremor and circumoral numbness.

High-yield facts · 11

  1. mg per cartridge = % x 10 x volume in mL. A 1.8 mL cartridge of 2% = 36 mg; 3% = 54 mg; 4% = 72 mg; 0.5% = 9 mg.S14
  2. Lidocaine with epinephrine: 7.0 mg/kg, absolute max 500 mg (US label/Malamed). AAPD for children: 4.4 mg/kg, max 300 mg.S14S18T1
  3. Mepivacaine: 6.6 mg/kg, absolute max 400 mg (Malamed); AAPD children 4.4 mg/kg, max 300 mg.S14S18T1
  4. Articaine: 7.0 mg/kg; the US label gives no separate absolute max, but many references cap it at 500 mg.sources varyS14S18T1
  5. Prilocaine: 8.0 mg/kg, absolute max 600 mg (Malamed); some references and the Canadian label use 500 mg.sources varyS14T1
  6. Bupivacaine: 1.3 mg/kg, absolute max 90 mg (Malamed); Canadian labeling allows 2 mg/kg up to 200 mg.sources varyS14T1
  7. Worked example: a 70 kg adult and 2% lidocaine with epi: 7.0 x 70 = 490 mg, which is under 500 mg; 490 / 36 = about 13.6, so about 13 cartridges.T1
  8. Worked example: a 20 kg child and 2% lidocaine at 4.4 mg/kg: 88 mg / 36 = about 2.4 cartridges.S18
  9. Convert pounds to kilograms by dividing by 2.2.T1
  10. When two anesthetics are used, the total dose should not exceed the lower of the two maximums.T1
  11. Overdose signs follow a pattern: early CNS excitation (talkativeness, slurred speech, tremor, metallic taste, circumoral numbness), then seizures, then CNS and cardiovascular depression.S14

Facts are written in our own words; each tag links to its source. Values marked "sources vary" differ between references, so check the one your program uses.