I feel very tired all the time. i am taking 5mg prednisone daily plus 2x seretide 500. is tiredness a side effect?

Not likely . . .: Seretide is sold in states as serevent (salmeterol), which along w/prednisone, suggests that you have either COPD or asthma. Feeling tired all the time isn't really a side effect of these meds (if anything, it's opposite effect of what's experienced w/prednisone). Therefore you need to go see your family doc (or who prescribed these meds) and tell him/her what you wrote. Perhaps not enough o2.