Hesperian Health Guides
Medicines for Numbing
Lidocaine is an anesthetic that can be injected around the edges of a wound to make the area numb so it will not hurt. This is useful before draining an abscess or stitching up a wound. If you decide to remove a blood clot from a painful hemorrhoid, use lidocaine first.
Inject both into and under the skin around where you are going to cut or sew, at points about 1 cm apart. First, clean the skin well, then slowly inject the lidocaine. Use about 1 ml of anesthetic for each 2 cm of skin. (Do not use more than 20 ml altogether.)
See Medicines, Tests, and Treatments (in development) for how to safely give injections.