Thank you so much for your response to my question. I had tried unsuccessfully to get this information from their website/drug info sheet.
Hi, most of the expired drugs lose their potency over time. There are only few drugs which change chemically to toxic drug. There were no adverse events reported with expired Advair Diskus. Hence, usually nothing will happen but further intake is not recommended. If the person experiences a hypersensitivity reaction or breath difficulties, consult physician without delay. Continue with fresh Advair Diskus as precribed, just wait and watch would be sufficient for few days. Take care and regards.