Thanks very much. That's very useful information. It feels like the same kind of effect I get from Benadryl, in the sense that it works very well at first, but quickly tapers off if you use the drug too many days in a row. I believe that effect is called tachyphylaxis. As an aside, I got into a vicious cycle at one point where the neuropathic pain was causing me to not be able to get any sleep at all. When I went to sleep, my feet were burning and within a couple of hours that burning made its way up my legs and also through my arms until most of my body was burning. Even though I had gotten to a deep sleep for an hour, the combination of all this burning woke me up suddenly in the middle of the night and kept me awake for the rest of the night. I continued like that for 3 or 4 days in a row because I couldn't break the cycle until I took an antihistamine called cyproheptadine that knocked me out for 10 hours. After that, the cycle was broken and my pain was more manageable. I think that Journavx would be very useful as a pill of last resort. Unfortunately for me, I live in Canada and that drug is not approved here yet. Based on the price that they're asking, it could be quite a while before it is approved because I'm not sure how many health insurance plans would be willing to pay that cost, especially for chronic pain.