Our travelling cat is having problems getting cartrophen while in US

Dusty was diagnosed with interstitial cystitis before leaving Canada. Our wonderful vet felt it best to wait until we arrived in Twxas to start the weekly injections of cartrophen. She felt we would have no problems. Wrong!!! No only have they not heard of it, but even after the Cdn manufacturer has offered to get it shipped here they won't give it. This response after consulting with Texas A& M university. They want to use amytriptyline, an antidepressant instead.
What should we do/ Trust our vet who feels the former is the better approach and try to find another Am vet, or go with the ammies? Would really appreciate a vet cooment on this, or of any member who has had a similar expereince. I beleive the Am equivalent of cartrophen is Adequan. Dusty is 6 and one half and has been a healthy big guy until he was attcked by a roving very affgressive cat on our back deck while mu husband was with him. Nothing but issues since.
Great forum!

Cartrophen is also known as Elmiron (http://www.veterinarypartner.com/Content.plx?P=A&A=1830&S=1&SourceID=52), perhaps the Texas vets would know it by that name? If you still can't get it, amitryptiline may not be a bad choice. Not only is it an anti-depressant (stress is frequently implicated in cystitis), but it's also an anti-inflammatory. According to this site (http://www.veterinarypartner.com/Content.plx?P=A&A=651&S=1&EVetID=0), it has a higher success rate in humans with interstitial cystitis than Cartrophen does. Studies on both of them pertaining to cats have been minimal.

The other thing you might be interested in for the future, if not now, would be adding Cosequin (http://www.nutramaxlabs.com/products/animal/cosequin/cosequin_cat_FAQ.asp#4) to your cat's food. Although usually prescribed for arthritis, it also has beneficial properties related to bladder health.

And lastly, what is Dusty's current diet? I'm hoping you're feeding him canned food and adding extra water to it, as that should be the primary treatment option in all cystitis cases.

Good luck, I hope some of this helps.