Have you experienced anthistamine withdrawal? After six weeks of use of one or the other, I started getting bad histamine reactions again to foods and supplements I was tolerating on the medication/s. Before the antihistamines, I was down to 9 or so foods I could safely eat and most Peaty foods weren't on that safe list. Was trying to eat less starch and grains, more fruit/juice and collagen, and take supplements to try to improve my situation. Most of the six weeks I took famotidine as cypro increased my exhaustion much more than famotidine. You can't cut or crush famotidine so I can't taper off that one. If you've experienced tolerance withdrawal how did you handle it? If I switch back to cypro, is the mechanism of action so different from famotidine that it would work better? If i go back to cypro, there's still the possiblity of tolerance and withdrawal from cypro down the road and maybe not so far away. I feared this would happen. My experience is that most meds and many supplements affect the body's natural feedback loop, then causing tolerance and/or withdrawal - which can be hellish.. I've been through benzo withdrawal (taken as prescribed, not abused)...i dont recommend these....Thousands of others have been through this hell as u can see in the online support groups. I do wonder though if the health of our body affects whether one ends up experiencing tolerance/withdrawal or not. I wonder if I'm more prone to tolerance/withdrawal than the average person? I've seen some nasty exepriences posted about anti histamine withdrawal (headahes and arms itching so bad they drew blood for a month) though not so much famotidine. I hope going off it isn't so bad. Feedback welcome.