Local anesthetic efficacy for oral surgery - Comparison of diphenhydramine and prilocaine

Objective. Diphenhydramine has been suggested as an alternative local anesthetic agent for patients claiming allergy to local anesthetics. The present study attempted to determine the local anesthetic efficacy of diphenhydramine for oral surgery. Study design. Seventeen patients claiming allergy to local anesthetics were given diphenhydramine as anesthetic alternative and compared with seven nonallergic control patients treated with prilocaine. After determining an average value of vitality score of neighboring and contralateral teeth by electrical pulp stimulation, molar and premolar teeth were extracted and postextraction vitality scores determined. Visual analogue scale, anesthesia onset times, and the incidence of pulpal and soft tissue anesthesia were analyzed nonparametrically by means of Mann-Whitney U tests. Results. The mean onset time of pulp anesthesia with diphenhydramine (range, 4 to 7.5 minutes), excluding one failure, was not significantly different from that of prilocaine; (range, 4 to 13 minutes). The duration of anesthesia was significantly longer and the visual analogue scale lower in the group receiving prilocaine in comparison with the group receiving diphenhydramine. Conclusion. In the small group studied, diphenhydramine administration provided adequate anesthesia before oral surgery; it may be useful as an anesthetic alternative in patients with histories of allergy to local anesthetics.