I also have the lido patches. They're strictly topical but the reason they last so long is because they're topical. The mechanism in the patch has a slow release over 12 hr period. It only has 3-5 percent lidocaine for that matter. When it comes to injections, there is no slow release mechanism so the lidocaine just does it's thing then leaves. Im only a patient, not a doc, but I would recommend asking about cortisone which is a steroid but it lasts a very long time, along with meds, thearapys and the patches, really bumps down the pain. I got in with a pain management doc who seems to know his stuff and he has schedule all these things and more. Nerve blocks are next on the list.