This link talks about varying the treatments to fit the pup. I know that we had to change things a few times for my last CT pup...and worked with all kinds of different meds. In the end, he did pass but I was able to keep him stable for much longer than would have been. Lomotil worked very well for him as I have said.
Tracheal Collapse Small Animal Hospital College of Veterinary Medicine University of Florida Agents used to control coughing at UF include butorphanol, hydrocodone and more recently Diphenoxylate and atropine ( Lomotil) . In times of decompensation I will often sedate the dog with acepromazine and add a low dose of prednisone to help reduce mucosal inflammation.
I find that individual dogs respond differently to different agents and each dog usually ends up with a different regimen. I have little experience with glucorticoid inhalants, or bronchodilators such as theophylline or torbutaline but these are used by some.