MW Clisinalpoteacy LD50(mM) Fetal rate at 5mM (%) Fetal rate 0.5mM (%) Annexin(+) PI(+) (Necrotic cells) (%) Prolain
binding
Log P (Aponnexin(+)PI(-) ptotin cells) (91) pKa % free base
at pH7.4
Dibucaine 344 20 0.09 98 92 84 90 462 22.3 8.5 7
Tctracaine 221 8 0.53 97 78 75 76 3.65 25.6 8.5 7
Bupivacaine 302 8 0.59 93 51 58 95 3.38 30.8 8.1 15
Rapivacaine 274 6 0.86 86 54 56.1 95 2.86 35.2 7.8 15
Mepivacaine 246 1.5 1.78 76 14 44.4 77 2.16 43 7.9 39
Lidocaine 234 2 2.35 88 5 41.8 64 1.81 46.2 7.9 25
Procaine 236 1 23.6 33 12 16.1 6 2.24 25.3 8.9 3
QX-314 263 0.4 53.4 14 7 7.4   2.4 18.1 9.5 0
P-values   *0.027†0.025 †0.014 †0.029 †0.018 †0.036   *0.027†0.035   #0.021 #0.021
Table 1: Correlation between physicochemical properties and toxicities of local anesthetics. Concentrations of local anesthetics (in mM) leading to half-maximal cytotoxic effects (LD50) after 24 h of incubation were calculated by probit regression analysis of concentration-response relationship experiments in HL-60 cells. Values are mean + SD. Partition coefficients with H-octanol/buffer at pH 7.4 (logp) and ionization contents (pKa), unionized fraction at pH 7.4, protein binding, molecular weight of the local anesthetics, and relative experimentally effective anesthetic concentrations from C fibers of isolated rabbit vagus were used to calculate Spearmanís rank correlation coefficients.