Why is this medication prescribed?
Burosumab-twza injection is used to treat X-linked hypophosphatemia (XLH; a rare, inherited form of rickets that causes poor bone growth and development) in adults and children one years of age and older. Burosumab-twza injection is in a class of medications called fibroblast growth factor 23 (FGF23) blocking antibodies. It works by blocking the action of a certain natural substance in the body which causes the symptoms of XLH.
How should this medicine be used?
Burosumab-twza injection comes as a solution (liquid) to be injected subcutaneously (under the skin) by a doctor or nurse. It is usually injected once every 2 weeks for children 17 years of age and younger, and once every 4 weeks for adults. Your doctor or nurse will inject the medication in either your upper arm, upper thigh, buttocks, or stomach area, and use a different injection site each time.
Tell your doctor if you are taking any phosphate supplements or certain vitamin D supplements such as calcitriol (Rocaltrol) or paricalcitol (Zemplar). You will need to stop taking these 1 week before you start treatment.
Your doctor may increase your dose (not more than once every 4 weeks), or may skip a dose, depending on the results of your lab tests.
Other uses for this medicine
This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.
What special precautions should I follow?
Before using burosumab-twza injection,
- tell your doctor and pharmacist if you are allergic to burosumab-twza, any other medications, or any of the ingredients in burosumab-twza injection. Ask your pharmacist for a list of the ingredients.
- tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
- tell your doctor if you have kidney disease. Your doctor may tell you not to use burosumab-twza injection.
- tell your doctor if you have or have ever had restless leg syndrome (RLS; a condition that causes discomfort in the legs and a strong urge to move the legs, especially at night and when sitting or lying down).
- tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while receiving burosumab-twza injection, call your doctor.
What special dietary instructions should I follow?
Unless your doctor tells you otherwise, continue your normal diet.
What should I do if I forget a dose?
If you miss an appointment to receive a dose, make another appointment as soon as possible.
What side effects can this medication cause?
Burosumab-twza injection may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- pain in arms, legs, or back
- muscle pain
Some side effects can be serious. If you experience any of these symptoms, call your doctor:
- redness, rash, hives, itching, swelling, pain, or bruising near or at the spot that the medication was injected
- rash or hives
- discomfort in the legs; a strong urge to move the legs, especially at night and when sitting or lying down
Burosumab-twza injection may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).
What other information should I know?
Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests before and during your treatment to check your body's response to burosumab-twza injection.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.