Glycopyrronium prolongs topical anaesthesia of oral mucosa and enhances absorption of lignocaine.

We have studied the effect of glycopyrronium on the anaesthetic action and absorption of topical lignocaine in 10 healthy, non-smoking volunteers. Lignocaine 100 mg was sprayed on the oral mucosa 15 min after random administration of glycopyrronium 4 micrograms kg-1 or normal saline i.v. Glycopyrronium decreased the mean analgesia score from 2 to 0.1 (2 = baseline; 0 = anaesthesia) at 4 min compared with a change from 2 to 0.5 after normal saline (P < 0.05). All scores returned to baseline by 40 min and 20 min in the glycopyrronium and control groups, respectively. The mean (SD) peak plasma lignocaine concentration was 0.57 (0.29) microgram ml-1 after glycopyrronium and 0.31 (0.10) microgram ml-1 after saline (P < 0.05) and were attained in 17 min (range 10-40 min) and 29 min (range 8-40 min), respectively. Pretreatment with glycopyrronium enhanced absorption and prolonged the analgesic action of topically administered lignocaine.