Duration of Action

LAs’ receptors on the voltage-gated sodium channels are integral membrane proteins. Predictably, the primary determinant of a LA’s duration of action is its protein-binding capacity (Table 1). LAs with high protein-binding capacity bind more tightly to and dissociate more slowly from their receptor sites and, therefore, have a longer duration of action (Table 4).2-13 Other factors affecting the duration of action of LAs include their lipid solubility, vascularity at the injection site, the presence of a vasoconstrictor in the formulation, and dosing.

Table 4. Range of Duration of Action of Various Local Anesthetic Agent Formulations.*18
  Infiltration: Pulpal Anesthesia Nerve Block: Pulpal Anesthesia Soft Tissue Anesthesia
Lidocaine 2 %, plain 5 min. 120 min.
Mepivacaine 3 %, plain 20-30 min. 45-65 min. 120-180 min.
Prilocaine 4 %, plain 10-15 min. 45-65 min. 180-240 min.
Lidocaine 2 %, w/epi. 55-70 min. 80-90 min. 180-300 min.
Mepivacaine 2 %, w/lev. 40-60 min. 60-90 min. 180-300 min.
Articaine 4 %, w/epi. 60-75 min. 120 min. 180-300 min.
Prilocaine 4 %, w. epi. 30-45 min. 50-70 min. 180-360 min.
Bupivacaine 0.5 %, 7 hrs. 47 hrs. 12 hrs.
*Based on data from Brandt RC, Anderson PF, McDonald NJ, et al. The pulpal anesthetic efficacy of articaine versus lidocaine in dentistry – a meta-analysis. JADA 2011;142(5):493-504.
dentalcare.com chat Let's get started!