Phenols in medicine

Even transient contact with phenol results in white blisters which, if left untreated, will destroy the underlying tissues. The ability of phenol to harden and destroy (sclerose) flesh, however, has found application in medicine. From 1904, 5 per cent solutions of phenol (usually in vegetable oil) have been used to seal off varicose veins and to shrink haemorrhoids.¹ When such solutions are injected into a nerve, the cells and surrounding cells are destroyed and thus the ability to transmit pain. While this is useful in relieving otherwise intractable pain, it does have its disadvantages. Not only is the painful stimulus removed, but also all sensation from the region served by the nerve. No more painful toe, for instance, but a numb foot with all the hazards of not having sensation in your foot for safe walking and balance.  

Despite the dramatic effect of phenol on animal tissue, chemists at ICI Pharmaceuticals Division, at Alderley Park, Macclesfield, Cheshire, decided to investigate the physiological and potential anaesthetic properties of this substance and its derivatives. The work, which was done during the 1970s, involved investigating substances that had previously been ignored because they were either insoluble in blood or plasma, or perceived to be too corrosive or toxic to warrant further study.