Reversal of soft-tissue local anesthesia with phentolamine mesylate in pediatric patients

Background. The authors evaluated the safety and efficacy of a formulation of phentolamine mesylate (PM) as a local anesthesia reversal agent for pediatric patients. Methods. A total of 152 pediatric subjects received injections of local anesthetic with 2 percent lidocaine and 1:100,000 epinephrine before undergoing dental procedures. The authors then randomized subjects to receive a PM injection or a control injection (sham injection in which a needle does not penetrate the tissue) in the same sites as the local anesthetic was administered in a 1:1 cartridge ratio after the procedure was completed. Over a two- to-four-hour period, they measured the duration of soft-tissue anesthesia and evaluated vital signs, pain and adverse events. Results. The median recovery time to normal lip sensation was 60 minutes for the subjects in the PM group versus 135 minutes for subjects in the control group. The authors noted no differences in adverse events, pain, analgesic use or vital signs, and no subjects failed to complete the study. Conclusions. PM was well-tolerated and safe in children 4 to 11 years of age, and it accelerated the reversal of soft-tissue local anesthesia after a dental procedure in children 6 to 11 years of age. Clinical Implications. PM can help dental clinicians shorten the post-treatment duration of soft-tissue anesthesia and can reduce the number of posttreatment lip and tongue injuries in children.