Duration of bupivacaine intradermal anesthesia when the bupivacaine is mixed with chloroprocaine.

In a double-blind trial in 20 human volunteers, the duration of intradermal anesthesia with a mixture of bupivacaine, 0.5 mg, and chloroprocaine, 3 mg, was compared with the duration of intradermal anesthesia obtained with either bupivacaine, 0.5 mg, or chloroprocaine, 3 mg, alone. The duration of intradermal anesthesia produced by the bupivacaine mixed with chloroprocaine, 36 +/- 16 (mean +/- 1 SD) minutes, was significantly less than the duration of the same amount of bupivacaine alone, 139 +/- 78 minutes. Duration of anesthesia with chloroprocaine alone, 24 +/- 11 minutes, was similar to the duration of anesthesia with chloroprocaine plus bupivacaine. A possible explanation for these results is that bupivacaine competes with chloroprocaine for nonspecific receptors at the biophase and in the surrounding nerve tissue.

RCT Entities:   Population Interventions Outcomes