Neutralized lidocaine with epinephrine for local anesthesia.

. The pain of infiltrating lidocaine with epinephrine into skin is reduced by the addition of sodium bicarbonate. The effect of varied concentrations of sodium bicarbonate on pain of infiltration of 1% lidocaine with epinephrine 1:100,000 was measured. Sodium bicarbonate at 40 and 100 meq/L of anesthetic solution caused significantly less pain than did 0 or 10 meq/L. The stability of epinephrine in a solution at pH 7.3 was also determined. Epinephrine concentration declined approximately 25% per week in anesthetic solution containing 100 meq/L sodium bicarbonate.