Local/Topical Anesthetics 

Updated: Mar 21, 2014
  • Author: James J Lamberg, DO; Chief Editor: Meda Raghavendra (Raghu), MD  more...
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Local and Topical Anesthetics

Amino esters include procaine, chloroprocaine, tetracaine, cocaine, and benzocaine. [1, 2, 3, 4, 5]

Amino amides include dibucaine, lidocaine, mepivacaine, prilocaine, bupivacaine, levobupivacaine, ropivacaine, articaine, and etidocaine.

Combinations include lidocaine/prilocaine (EMLA) and lidocaine/tetracaine (Rapydan), lidocaine/epinephrine/tetracaine (LET), and tetracaine/adrenaline/cocaine (TAC)

Topical anesthetics include benzocaine, lidocaine, cocaine, proparacaine, and oxybuprocaine.

Bupivacaine: Useful because of long duration, commonly used in spinals, high-quality sensory block relative to motor block

Chloroprocaine: Most rapid hydrolysis among ester class, useful in obstetrics owing to rapid onset and low risk of systemic toxicity or fetal exposure

Cocaine: Vasoconstrictor properties, central nervous system stimulation (hypertension, tachycardia, coronary ischemia)

Lidocaine: Very versatile anesthetic that is used for topical, regional, neuraxial, and intravenous anesthesia

Ropivacaine: Greatest margin of safety among long-acting local anesthetics

Tetracaine: Useful in spinals because of rapid onset, long duration, less sensatory blockade than bupivacaine

Topical formulations

Benzocaine: 20% solution for mucosal anesthesia; risk of methemoglobinemia, especially with repeated doses

Cocaine: 4% solution for topical anesthesia (sinus surgery, awake intubation) or 11.8% TAC for wound repair

EMLA: 2.5% lidocaine and 2.5% prilocaine eutectic mixture for minor procedures (pediatric IV placement); onset, 45-60 minutes; duration, 2 hours; typical adult dose, 2.5-10 g

J-Tip: 1% buffered lidocaine for minor procedures (pediatric IV placement), needle-free pressure-injection device

LET: 4% lidocaine plus 0.1% epinephrine and 0.5% tetracaine for minor procedures (laceration repair), as aqueous solution or methylcellulose gel

LMX: 4% liposomal solution for minor procedures (pediatric IV placement); onset, 30 minutes, maximum 100 cm2 application area in children < 10 kg

Table 1. EMLA Maximum Dosing (Open Table in a new window)

Age Weight Maximum Dose
0-3 months < 5 kg 1 g
3-12 months >5 kg 2 g
1-6 years >10 kg 10 g
7-12 years >20 kg 20 g

 

Table 2. Onset, Maximum Dose, and Duration of Anesthetics (Open Table in a new window)

Drug Onset Maximum Dose (With Epinephrine) Duration (With Epinephrine)
Lidocaine Rapid 4.5 mg/kg (7 mg/kg) 120 min (240 min)
Mepivacaine Rapid 5 mg/kg (7 mg/kg) 180 min (360 min)
Bupivacaine Slow 2.5 mg/kg (3 mg/kg) 4 hours (8 h)
Ropivacaine Medium 2-3 mg/kg 3 hours (6 h)
Levobupivacaine Medium 2 mg/kg or 400 mg in 24 hours 4-6 hours (8-12 h)
Procaine Slow 8 mg/kg (10 mg/kg) 45 min (90 min)
Chloroprocaine Rapid 10 mg/kg (15 mg/kg) 30 min (90 min)
Etidocaine Rapid 2.5 mg/kg (4 mg/kg) 4 hours (8 h)
Prilocaine Medium 5 mg/kg (7.5 mg/kg) 90 min (360 min)
Tetracaine Slow 1.5 mg/kg (2.5 mg/kg) 3 hours (10 h)

Calculate the maximum tolerable dose by considering the dose to be used, patient weight, and any history of heart disease.

Table 3. Pharmacokinetics of Common Local Anesthetics (Open Table in a new window)

Local pKa Nonionized Potency Topical Local Intravenous Peripheral Epidural Spinal
Procaine 8.9 3% at pH 7.4 1 No Yes No Yes No Yes
Chloroprocaine 8.7 5% at pH 7.4 2 No Yes Yes Yes Yes Yes
Tetracaine 8.5 7% at pH 7.4 8 Yes Yes No No No Yes
Lidocaine 7.9 24% at pH 7.4 2 Yes Yes Yes Yes Yes Yes
Mepivacaine 7.6 39% at pH 7.4 2 No Yes No Yes Yes Yes
Prilocaine 7.9 24% at pH 7.4 2 Yes Yes Yes Yes Yes Yes
Bupivacaine 8.1 17% at pH 7.4 8 No Yes No Yes Yes Yes
Levobupivacaine 8.1 17% at pH 7.4 8 No Yes No Yes Yes Yes
Ropivacaine 8.1 17% at pH 7.4 6 No Yes No Yes Yes Yes