Lidocaine is a sodium channel blocking agent.
It stops nerve impulses and this how it works to numb pain.
I have had huge success with these patches over the years.
What does happen however, is that some insurances will not pay for them, unless you have a prior diagnosis of shingles.
But then if you are denied, your doctor can appeal that with medical need by fax to your carrier. It might work in your favor.
One needs to be patient with these patches as they don't work instantly...it may be a day 2 or 3 days to show benefit.
Also you have to place them carefully. I find looking at an anatomy book with nerve pathways, helps. Putting them on the endpoints of pain, works less, than on the pathway of the nerve axon.
I place 1/2 patch on the tops of my feet therefore for burning foot pain. 1/2 patch behind the knee sometimes, and when I had the terrible MP neuropathy I used 1/2 patch in 2 areas at the top of the thigh... in 2 weeks the nerve stopped firing, and I was in a remission! (lateral femoral nerve).
I think doctors who deny this potential treatment do so because they don't understand it or how to effect success with it.