Originally Posted by
sojourner 
This is definitely only to be used by a doctor - most likely a pain clinic physician who does epidural nerve blocks for pain.
My pain management doctor uses it to deaden my tailbone area when I get steroid injections for my sciatica.
It was also used to do a brachial block (up in the armpit area to deaden the entire arm) in both of my arms when I had surgery to move the ulnar nerves that were compressed.