Efgartigimod alfa-hyaluronidase is used to treat myasthenia gravis in adults.

Your doctor will make sure you have the correct type to be treated with efgartigimod alfa-hyaluronidase.

Efgartigimod alfa-hyaluronidase may also be used for purposes not listed in this medication guide.

Tell your doctor if you have or have ever had:

• use any other medications;
• if you are scheduled to receive a vaccine; or
• an active or recent infection.

Tell your doctor if you recently received a vaccine.

Make sure you are current on all vaccines before you start using efgartigimod alfa-hyaluronidase.

It is not known if efgartigimod alfa-hyaluronidase will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

Tell your baby's doctor if you used efgartigimod alfa-hyaluronidase during pregnancy. It could affect your baby's vaccination schedule.

Ask a doctor if it is safe to breastfeed while using this medicine.

Use Efgartigimod Alfa-Hyaluronidase (Subcutaneous) exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

Get emergency medical help if you have signs of an allergic reaction: hives, difficult breathing, swelling of your face, lips, tongue, or throat.

You may get infections more easily. Call your doctor right away if you have signs of infection such as:

• fever, chills, sore throat;
• mouth sores, red or swollen gums;
• pale skin, easy bruising, unusual bleeding; or
• chest discomfort, wheezing, dry cough or hack, rapid weight loss.

Your treatment may be delayed if you have certain side effects.

Common side effects may include:

• pain and burning when you urinate;
• pain, bruising, swelling, or irritation where the medicine was injected;
• muscle pain, 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.

Avoid receiving a "live" vaccine. The vaccine may not work as well while you are receiving efgartigimod alfa-hyaluronidase. Live vaccines include measles, mumps, rubella (MMR), rotavirus, typhoid, yellow fever, varicella (chickenpox), and zoster (shingles).