Warnings and side effects

You/your child should not take CRYSVITA if you/they:

Are allergic to burosumab or any of the other ingredients in this medication
Are taking any phosphate or active vitamin D
Already have a high level of phosphate in the blood (called hyperphosphatemia)
Have severe kidney disease or kidney failure

To help avoid side effects and ensure proper use of CRYSVITA, talk to your healthcare professional before you or your child take CRYSVITA. This includes discussing any health conditions or problems, including if you or your child are:

Taking phosphates or active vitamin D, such as those with the active ingredient calcitriol or alfacalcidol. There are some non-active vitamin D supplements that can be used and your healthcare professional will advise which ones these are.
Having problems with your parathyroid glands.

Tell your healthcare professional about all the medicines you or your child take, including any drugs, vitamins, minerals, natural supplements or alternative medicines. Studies to test how CRYSVITA interacts with other medicines have not been done.

Woman sitting down at a doctor appointment

Not actual patient.

Other warnings to know about:

Skin reactions

You or your child may get skin reactions where the injection is received. If they are severe, contact your healthcare professional right away.

CRYSVITA should not be given to children with XLH under 6 months of age because the safety and effects of the medicine have not been studied in this age group.

Pregnancy and breast-feeding

If you are pregnant or breast-feeding, think you might be pregnant or are planning to have a baby, ask your healthcare professional or pharmacist for advice before taking this medicine. This is because it is not known if CRYSVITA will affect the baby.

Females who are able to become pregnant should use an effective method of birth control during treatment with CRYSVITA and for at least 14 weeks after stopping treatment. Talk to your healthcare professional about birth control methods that you can use during this time. Tell your healthcare professional right away if you become pregnant during treatment with CRYSVITA.

It is not known if CRYSVITA passes into breast milk, and a risk to newborns or infants cannot be ruled out. If you have questions, ask your healthcare professional.

Possible side effects

Like all medicines, CRYSVITA can cause side effects, although not everybody gets them.

Side effects in adults may include:

Back pain
Headache
Tooth infection
Restless leg syndrome
Constipation
Low vitamin D
Dizziness
Muscle spasm

Side effects in children may include:

Tooth abscess (infection)
Toothache
Cough
Headache
Vomiting
Nausea
Diarrhea
Constipation
Tooth decay or cavities
Rash
Pain in muscles (myalgia), hands and feet
Reactions where the injection was given, which may include:
- Redness or rash
- Pain or itching
- Swelling
- Bleeding or bruising
These injection site reactions are usually mild and occur within a day after the injection and usually get better in around 1 to 3 days.
Fever
Low vitamin D
Dizziness

If you or your child experience any side effects not listed here, or have a troublesome symptom that becomes bad enough to interfere with daily activities, talk to your healthcare professional.

Not actual patient.