The efficacy profile of lidocaine as a local anesthetic is characterized by a rapid onset of action and intermediate duration of efficacy. Therefore, lidocaine is suitable for infiltration, block and surface anesthesia. Longer-acting substances such as bupivacaine are sometimes given preference for subdural and epidural anesthesias; lidocaine, on the other hand, has the advantage of a rapid onset of action. Epinephrine (aka adrenaline) vasoconstricts arteries reducing bleeding and also delays the resorption of lidocaine, almost doubling the duration of anaesthesia. For surface anesthesia several formulations are available that can be used e.g. for endoscopies, before intubations etc. Buffering the pH of lidocaine makes local freezing less painful.[2] Lidocaine drops can be used on the eyes for short ophthalmic procedures. Ref:  Lab Arlex.  Hemorroids. criptitis. Inflammation anus and rectum. anestesic. post surgery. Noladerm