[Studies on the stability of local anaesthetics containing adrenaline (author's transl)]

Local toxic reactions from adrenaline following nerve block anaesthesia have been observed by many workers. Because of this potential danger we studied the changes of anaesthetic solutions containing adrenaline during a longer storage period. The measurements show a drop in the pH of the solutions caused by decomposition of adrenaline. This effect of storage is not detectable with the naked eye but makes analytical procedures necessary. Molecular oxygen and light decompose the solutions rapidly. After a storage period of some months the acidity of the solutions is comparable to concentrated acetic acid, a fact which could lead to local complications.