There is an older school of thought that would actually advise against water changes during the times of high ammonia and nitrite. This is because if there isn't enough bacteria to process the waste, removing the waste won't solve the problem! The bacteria must have the food present to grow and build up. Removing the waste may make the owner and the fish feel better, but only prolongs the problem.
Edit: I never really understood why people immediately suggest water changes. The prime and stability on the other hand, are suggestions that I will agree with.