Phentolamine mesylate for accelerating recovery from lip and tongue anesthesia.

Phentolamine mesylate, at dosages from 0.4 to 0.8 mg in adults and adolescents and at dosages from 0.2 to 0.4 mg in children aged 4 to 11 years, has been proven to be safe and effective for the reversal of soft tissue anesthesia (lip and tongue numbness) and the associated functional deficits resulting from a local dental anesthetic injection containing a vasoconstrictor. Its ability to block a-adrenergic receptors on blood vessels induces vasodilation and enhances the redistribution of the local anesthetic away from the injection site. The low dosages administered for dental local anesthetic reversal in all likelihood accounts for the lack of significant cardiovascular effects that are associated with the medical use of the drug for hypertensive conditions associated with catecholamine excess.