Dermal patch anaesthesia: comparison of 10% lignocaine gel with absorption promoter and EMLA cream

The analgesic effects of transdermally applied 10% lignocaine aquagel containing 3% glycyrrhetinic acid monohemiphthalate disodium (as an absorption enhancer) and EMLA cream were compared on the forearms of 34 adult volunteers in a double-blind fashion. The mean pinprick pain scores (graded by noting the number of painful pinpricks out of five) at 30, 60 and 90 min after application and 30 min after removal of the anaesthetics were 3.3 (0.3) (mean SE), 1.2 (0.3), 0.3 (0.1) and 0.3 (0.1) respectively, in the lignocaine gel group. Corresponding scores were 3.5 (0.3), 1.5 (0.3), 0.7 (0.2) and 0.1 (0.1) respectively, in the EMLA group. Insertion of a 26-gauge needle into the treated skin to a depth of 1 mm at 90 min after application was not painful in 91% of the volunteers in the lignocaine gel group and 88% of those in the EMLA group. There was no significant difference in any of the corresponding pain scores between the two groups.