How to Administer Subcutaneous Crysvita Safely: Important Nursing Guidelines

Crysvita (burosumab) is a monoclonal antibody treatment for adults and children with X-linked hypophosphatemia. It replaces a missing protein, helps the kidneys retain phosphate, and supports healthy bone mineralization. As a nurse, your role in preparing, administering, and monitoring subcutaneous Crysvita is vital to patient safety and treatment success.

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1. Preparing for Injection

Before you begin, gather all supplies and verify the prescription.

Supplies Checklist

• Crysvita vial(s) refrigerated at 2–8 °C (do not freeze)
• Sterile syringe (0.5 mL or 1 mL) and 27- to 30-gauge needle
• Alcohol swabs
• Gauze or cotton ball
• Adhesive bandage
• Sharps disposal container
• Gloves

Verification Steps

1. Confirm patient identity using two identifiers.
2. Compare the vial label with the patient’s order: drug name, concentration, and expiration date.
3. Inspect the solution: it should be clear to slightly opalescent, colorless to pale yellow. Do not use if cloudy or contains particles.

Storage Handling

• Keep vials refrigerated until 30 minutes before injection.
• Bring to room temperature (do not warm in microwave or hot water).
• Gently invert the vial; avoid shaking to prevent foam formation.

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2. Aseptic Technique and Dosage Preparation

1. Perform hand hygiene and don gloves.
2. Wipe the vial stopper with an alcohol swab; let it dry.
3. Attach the sterile needle to your syringe.
4. Draw air into the syringe equal to the prescribed volume of Crysvita.
5. Inject air into the vial, then invert the vial and withdraw the correct dose.
6. Remove air bubbles by tapping the syringe; push the plunger slightly until a drop of solution appears at the tip.
7. Replace the needle with a fresh, shorter needle (if facility policy allows) to minimize patient discomfort.

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3. Injection Site Selection and Rotation Schedule

Proper site selection and rotation reduce the risk of local reactions and lipodystrophy.

Recommended Injection Sites

• Abdomen (avoid a 2-inch circle around the navel)
• Anterior thighs
• Upper outer arms (posterolateral surface)
• Upper buttocks

Rotation Schedule
To allow tissues to recover and lower the chance of site reactions, follow a rotation plan:

Week	Site
1	Left abdomen
2	Right abdomen
3	Left anterior thigh
4	Right anterior thigh
5	Left upper arm
6	Right upper arm
7	Left upper buttock
8	Right upper buttock

After week 8, return to week 1’s site. Adjust based on patient preference and comfort, ensuring at least 1 inch separation from the last injection site.

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4. Administering the Injection

1. Cleanse the selected site with an alcohol swab; allow to air dry completely.
2. Stretch the skin taut or pinch a fold (depending on patient’s subcutaneous fat).
3. Insert the needle at a 45° to 90° angle, based on the patient’s body habitus.
4. Inject the full dose steadily over 10–30 seconds to reduce discomfort.
5. Withdraw the needle and apply gentle pressure with gauze.
6. Apply an adhesive bandage if needed.

Encourage the patient to remain still during the injection and to breathe normally. A quick, confident motion often causes less discomfort.

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5. Monitoring and Managing Burosumab Injection Site Reactions

Injection site reactions are common with burosumab. These may include:

• Redness (erythema)
• Swelling (induration)
• Pain or tenderness
• Itching

Mild Reactions

• Usually resolve within 24–48 hours.
• Manage with cool compresses for 10–15 minutes, 2–3 times daily.
• Over-the-counter analgesics (e.g., acetaminophen) can relieve pain.

Moderate to Severe Reactions

• Marked swelling, intense pain, or warmth at the site.
• Consider applying a topical corticosteroid per physician’s order.
• If reaction persists beyond 72 hours or worsens, notify the prescriber.

Document the size (centimeters), appearance, and patient’s description of any reaction.

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6. Patient Education and Engagement

Educating patients and caregivers empowers them to participate in safe home administration.

Key teaching points:

• Show the rotation schedule and have them mark each site on a calendar.
• Demonstrate the injection technique step by step.
• Emphasize gentle handling—no shaking or frothing the solution.
• Discuss common injection site reactions and how to manage mild symptoms at home.
• Encourage them to record each injection: date, site, dose, and any reactions.

Patients should know when to reach out for help. For a free, online symptom check, using the doctor approved Ubie Symptom Checker, click here: https://ubiehealth.com/

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7. Ongoing Monitoring and Documentation

Regular monitoring ensures Crysvita’s effectiveness and patient safety.

Clinical Monitoring

• Serum phosphorus levels every 2–4 weeks until normalized, then every 3 6 months.
• Serum parathyroid hormone, calcium, and vitamin D levels per protocol.
• Renal ultrasound to screen for nephrocalcinosis periodically.
• Growth parameters (in children): height velocity and weight.

Adverse Event Reporting

• Document all reactions and adverse events in the medical record.
• Report serious events to pharmacovigilance as required.

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8. Special Considerations

• Pediatric Patients: Use distraction techniques or topical anesthetic cream if approved by policy.
• Needle Phobia: Offer a calm environment, guided imagery, or slow breathing exercises.
• Immunogenicity: Rarely, patients develop anti-burosumab antibodies. Report unusual loss of efficacy.

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9. Prompt for Life-Threatening or Serious Concerns

While most injection site reactions are mild, always be vigilant for signs of a severe allergic reaction:

• Difficulty breathing or wheezing
• Swelling of face, lips, tongue, or throat
• Rapid heartbeat or dizziness
• Hives or widespread rash

If any of these occur, instruct the patient to seek immediate medical attention or call emergency services. Remind them to speak to a doctor about anything that could be life threatening or serious.

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10. Summary of Key Nursing Guidelines

• Store Crysvita properly and inspect solution.
• Use strict aseptic technique when preparing and administering.
• Follow a structured injection site rotation schedule.
• Monitor for and manage burosumab injection site reactions.
• Educate patients on self-administration, site rotation, and symptom monitoring.
• Perform regular laboratory and clinical assessments.
• Document thoroughly and report serious adverse events.

By adhering to these guidelines, you help ensure that Crysvita therapy is both safe and effective, supporting optimal outcomes for patients with X-linked hypophosphatemia. Always maintain open communication with the prescribing physician and empower patients to report concerns promptly.