There is no fix for CT. It may progressively get worse with age. There are surgical procedures, but a low success rate on them.
Preventing coughing lessens the damage that occurs from the cough. There are others medications available that may be of use if his symptoms become worse.
Also, limit excitement, exercise, or any triggers of coughing.
Also see:
http://www.yorkietalk.com/forums/3189940-post14.html