this is the sound of an asthma attack... that doesn't happen. this is the sound of better breathing. fasenra is a different kind of asthma medication. it's not a steroid or inhaler. fasenra is an add-on treatment for asthma driven by eosinophils. it's one maintenance dose every 8 weeks. it helps prevent asthma attacks, improve breathing, and lower use of oral steroids. nearly 7 out of 10 adults with asthma may have elevated eosinophils. fasenra is designed to target and remove them. fasenra is not a rescue medication or for other eosinophilic conditions. fasenra may cause allergic reactions. get help right away if you have swelling of your face, mouth, and tongue, or trouble breathing. don't stop your asthma treatments unless your doctor tells you to. tell your doctor if you have a parasitic infection or your asthma worsens. headache and sore throat may occur.