The label on the box or cover will tell you how many doses are in your Pulmicort Flexhaler. On the body of Pulmicort Flexhaler, there is a dose indicator window just below the mouthpiece. When a red mark appears at the top of the window, there are 20 doses of medicine remaining. You should get your next Pulmicort Flexhaler (budesonide). When the red mark reaches the bottom of the window, your inhaler should be discarded as it may no longer deliver the correct amount of medication.