Crysvita Side Effects

Generic name: burosumab

Medically reviewed by Drugs.com. Last updated on Mar 31, 2025.

Note: This document provides detailed information about Crysvita Side Effects associated with burosumab. Some dosage forms listed on this page may not apply specifically to the brand name Crysvita.

Applies to burosumab: subcutaneous solution.

Serious side effects of Crysvita

Along with its needed effects, burosumab (the active ingredient contained in Crysvita) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking burosumab:

More common side effects

• bleeding, blistering, burning, coldness, discoloration of the skin, feeling of pressure, hives, infection, inflammation, itching, lumps, numbness, pain, rash, redness, scarring, soreness, stinging, swelling, tenderness, tingling, ulceration, or warmth at the injection site
• bone malformations
• confusion
• cough or hoarseness
• fast or irregular heartbeat
• fever
• frequent bone fractures
• hives, itching, skin rash
• irritation
• joint pain, stiffness, or swelling
• mood or mental changes
• muscle cramps in the hands, arms, feet, legs, or face
• numbness and tingling around the mouth, fingertips, or feet
• pain in the arm or leg
• redness of the skin
• seizures
• slowed growth
• stomach cramps
• swelling of the eyelids, face, lips, hands, or feet
• tightness in the chest
• tremor
• troubled breathing or swallowing

Other side effects of Crysvita

Some side effects of burosumab may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common side effects

• aching or discomfort in the lower legs or sensation of crawling in the legs
• back pain
• constipation
• diarrhea
• difficulty with moving
• dizziness
• headache
• muscle ache, pain, spasm, or stiffness
• nausea
• toothache
• vomiting

For healthcare professionals

Applies to burosumab: subcutaneous solution.

General adverse events

The more commonly reported adverse reactions have included injection site reactions, muscle spasms, back pain, tooth infections, restless leg syndrome, dizziness, headache, decreased vitamin D, and constipation.^[Ref]

Metabolic

• Very common (10% or more): Vitamin D decreased (up to 37%)
• Common (1% to 10%): Blood phosphorus increased

Increased blood phosphorus was reported in 6% of adult patients during clinical trials. There were no reports of increased blood phosphorus in pediatric clinical trials.

Gastrointestinal

• Very common (10% or more): Vomiting (up to 48%), toothache (up to 23%), tooth abscess (up to 34%), dental caries (up to 31%), diarrhea (up to 24%), constipation (up to 17%)
• Common (1% to 10%): Nausea

Hypersensitivity

• Frequency not reported: Hypersensitivity reactions

In pediatric patients, the more frequent events that were considered potential hypersensitivity events included rash (22%), injection site rash (6%), and urticaria (5%). In adult patients approximately 6% of patients in both the study group and placebo group experience mild or moderate hypersensitivity reactions that did not require drug discontinuation.

Dermatologic

• Very common (10% or more): Rash (up to 27%)

Rash includes pruritic, maculopapular, and pustular rashes

Musculoskeletal

• Very common (10% or more): Extremity pain (up to 46%), myalgia (up to 17%), back pain (15%); muscle spasm (up to 19%)
• Common (1% to 10%): Spinal surgery

Spinal stenosis is common in adults with X-linked hypophosphatemia (XLH). In phase 2/3 studies, 6 patients (n=176) underwent spinal surgery for what appeared to involve progression of a preexisting spinal stenosis. It is unknown if therapy exacerbates spinal stenosis or spinal cord compression.

Other

• Very common (10% or more): Pyrexia (up to 55%)

Local

• Very common (10% or more): Injection site reaction (up to 67%)

Injection site reactions have included erythema, pruritus, swelling, pain, rash, bruising, discoloration, discomfort, hematoma, hemorrhage, induration, macule, and urticaria at the injection site

Nervous system

• Very common (10% or more): Headache (up to 73%), dizziness (up to 15%), restless leg syndrome (12%)

Respiratory

• Very common (10% or more): Cough (up to 52%)

Frequently asked questions

• What conditions is Crysvita (burosumab-twza) used to treat?

Further information

Crysvita side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer