Get emergency medical help if you have signs of an allergic reaction to Ultomiris: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Some side effects may occur during the injection. Tell your caregiver if you feel light-headed or if you have chest pain, trouble breathing, or swelling in your face.
Call your doctor right away if you have signs of infection such as:
muscle pain with flu-like symptoms;
fever and a rash;
fever and a headache;
headache and stiffness in your neck or back;
headache and nausea or vomiting;
confusion; or
your eyes may be more sensitive to light.
Call your doctor at once if you have symptoms of gonorrhea, such as:
pain or burning when you urinate;
pain or swelling of the genital or rectal area;
unusual vaginal bleeding; or
foul discharge from the penis or vagina.
If you stop using Ultomiris, tell your doctor if you have any new or worsening symptoms, such as: tiredness, confusion, stomach pain, chest pain, trouble breathing or swallowing, (in men) trouble having an erection, blood in your urine, a seizure, or loss of consciousness.
Common Ultomiris side effects may include:
fever;
high blood pressure;
diarrhea, nausea, vomiting;
headache; or
cold symptoms such as stuffy nose, sneezing, sore throat.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
 Ultomiris side effects (more detail)
