Safe dosage of local anaethesia
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local anesthetic maximum recommended doses lidocaine bupivacaine official guideline
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Safe local anesthetic dose depends on the drug, concentration, body weight, injection site, whether epinephrine is used, age, liver/heart disease, pregnancy, and whether drugs are mixed. It should be calculated by a trained clinician before injection.
Common maximum doses for infiltration in a healthy patient
| Drug | Usual maximum dose |
|---|---|
| Lidocaine plain | 4.5-5 mg/kg, usually do not exceed 300 mg |
| Lidocaine + epinephrine | 7 mg/kg, often maximum 500 mg |
| Bupivacaine plain | 2.5 mg/kg |
| Bupivacaine + epinephrine | 3 mg/kg |
| Ropivacaine | Often 2-3 mg/kg depending on block and protocol |
For reference, 1% lidocaine = 10 mg/mL and 0.5% bupivacaine = 5 mg/mL.
Formula: maximum volume (mL) = [maximum mg/kg × weight (kg)] ÷ [concentration (%) × 10]. The Harriet Lane Handbook lists 5 mg/kg for lidocaine, 7 mg/kg with epinephrine, 2.5 mg/kg for bupivacaine, and 3 mg/kg with epinephrine (p. 206).
Formula: maximum volume (mL) = [maximum mg/kg × weight (kg)] ÷ [concentration (%) × 10]. The Harriet Lane Handbook lists 5 mg/kg for lidocaine, 7 mg/kg with epinephrine, 2.5 mg/kg for bupivacaine, and 3 mg/kg with epinephrine (p. 206).
Example only: A 60 kg adult receiving plain 1% lidocaine:
5 mg/kg × 60 = 300 mg maximum.
At 10 mg/mL, that is 30 mL, but clinicians normally use the lowest effective dose and keep a margin below the limit.
5 mg/kg × 60 = 300 mg maximum.
At 10 mg/mL, that is 30 mL, but clinicians normally use the lowest effective dose and keep a margin below the limit.
Important safety points
- Lower doses may be necessary for children, frail older adults, pregnancy, liver disease, heart failure, low cardiac output, or interacting medicines.
- Do not simply add maximum doses when mixing agents. Their toxicity is additive.
- Highly vascular sites and accidental intravascular injection can cause toxicity at lower total doses.
- Bupivacaine has greater risk of severe cardiac toxicity than lidocaine.
- Topical anesthetics and mucosal application can also be absorbed systemically and count toward exposure.
- Specific product labeling and the procedure type can set lower limits. For example, DailyMed’s lidocaine labeling specifies no more than 4.5 mg/kg or 300 mg for that product.
Stop and seek emergency help immediately for tingling around the mouth, metallic taste, ringing ears, dizziness, agitation, muscle twitching, seizure, severe drowsiness, slow/irregular heartbeat, or collapse. These can indicate local anesthetic systemic toxicity.
Tell me the drug name/concentration, patient age and weight, use of epinephrine, and intended procedure/site, and I can help calculate the usual maximum volume, but this should be checked by the clinician administering it.
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