I've been on seretide for about 3 months now, but have only recently noticed that I get some paradoxical broncospasm when taking it. I take 2 puffs, twice a day with a spacer. My peak flow before taking it at the moment, is in the region on 510-540, within 10 mins of taking the seretide my reading drop to 400-420 my chest becomes very tight and I have trouble breathing without coughing up phlegm, I then need to use 2-4 puffs of reliever, and a further 10-15 minutes and my peak flow is reaching 550-560 (personal best is 570). I am otherwise having no issues with my asthma at the moment.
Any suggestions why this would start now, and any suggestions what I could do to avoid it?