THE APPREHENSION with which otolaryngologists view the matter of topical anesthesia is well known. Differences in opinion and technic are so great as to suggest that the only single point of agreement is on the general hazards of anesthesia. Confusion is attributable partly to a lack of pertinent experimental work on animals. Although there are admittedly sharp limitations to the applicability of animal studies to man, virtually all that is known about the physiological action of these drugs is based on laboratory studies, and doses officially approved as safe for man were calculated directly from animal responses. However, most laboratory investigations on topical anesthetics have been pursued by injection methods, and the literature on toxicity of cocaine and tetracaine hydrochloride (pontocaine hydrochloride®) with topical application is sketchy.
Runge and Schmidt,1 in one of the early articles on tetracaine, stated that topical application was similar to subcutaneous injection and that
RUBIN HJ. TOXICITY OF CERTAIN TOPICAL ANESTHETICS USED IN OTOLARYNGOLOGYAn Experimental Study. AMA Arch Otolaryngol. 1951;53(4):411–420. doi:10.1001/archotol.1951.03750040060007