DUPIXENT can cause serious side effects, including:

• Allergic reactions. DUPIXENT can cause allergic reactions that can sometimes be severe. Stop using DUPIXENT and tell your healthcare provider or get emergency help right away if you get any of the following symptoms:
  • breathing problems or wheezing
  • fast pulse
  • fever
  • general ill feeling
  • swollen lymph nodes
  • swelling of the face, lips, mouth, tongue, or throat
  • hives
  • itching
  • nausea or vomiting
  • fainting, dizziness, feeling lightheaded
  • joint pain
  • skin rash
  • cramps in your stomach-area
• Eye problems. Tell your healthcare provider if you have any new or worsening eye problems, including eye pain or changes in vision, such as blurred vision. Your healthcare provider may send you to an ophthalmologist for an eye exam if needed.
• Inflammation of your blood vessels. Rarely, this can happen in people with asthma who receive DUPIXENT. This may happen in people who also take a steroid medicine by mouth that is being stopped or the dose is being lowered. It is not known whether this is caused by DUPIXENT. Tell your healthcare provider right away if you have:
  • rash
  • worsening shortness of breath
  • persistent fever
  • chest pain
  • a feeling of pins and needles or numbness of your arms or legs
• Joint aches and pain. Some people who use DUPIXENT have had trouble walking or moving due to their joint symptoms, and in some cases needed to be hospitalized. Tell your healthcare provider about any new or worsening joint symptoms. Your healthcare provider may stop DUPIXENT if you develop joint symptoms.

The most common side effects in patients with chronic rhinosinusitis with nasal polyposis include:

• injection site reactions
• eye and eyelid inflammation, including redness, swelling, and itching, sometimes with blurred vision
• high count of a certain white blood cell (eosinophilia)
• trouble sleeping (insomnia)
• toothache
• gastritis
• joint pain (arthralgia)