Or other problems caused by eosinophils. fasenra™ may cause headache, sore throat, and 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 your asthma worsens or if you have a parasitic infection. fasenra™ is a targeted treatment for eosinophilic asthma. that's important. ask an asthma specialist about fasenra™. my dbut now, i take used tometamucil every day.sh it traps and removes the waste that weighs me down, so i feel lighter. try meta...