Crysvita Special Precautions

Traceability: In order to improve the traceability of biological medicinal products, the name and the batch number of the administered product should be clearly recorded within the patient's records.
Ectopic mineralisation: Ectopic mineralisation, as manifested by nephrocalcinosis, has been observed in patients with XLH treated with oral phosphate and active vitamin D analogues; these medicinal products should be stopped at least 1 week prior to initiating burosumab treatment (see Dosage & Administration).
Monitoring for signs and symptoms of nephrocalcinosis, e.g. by renal ultrasonography, is recommended at the start of treatment and every 6 months for the first 12 months of treatment, and annually thereafter. Monitoring of plasma alkaline phosphatase, calcium, parathyroid hormone (PTH) and creatinine is recommended every 6 months (every 3 months for children 1-2 years) or as indicated.
Monitoring of urine calcium and phosphate is suggested every 3 months.
Hyperphosphataemia: Levels of fasting serum phosphate should be monitored due to the risk of hyperphosphatemia. To decrease the risk for ectopic mineralisation, it is recommended that fasting serum phosphate is targeted in the lower end of the normal reference range for age. Dose interruption and/or dose reduction may be required (see Dosage & Administration). Periodic measurement of post prandial serum phosphate is advised.
Serum parathyroid hormone: Increases in serum parathyroid hormone have been observed in some XLH patients during treatment with burosumab. Periodic measurement of serum parathyroid hormone is advised.
Injection site reactions: Administration of burosumab may result in local injection site reactions. Administration should be interrupted in any patient experiencing severe injection site reactions (see Adverse Reactions) and appropriate medical therapy administered.
Hypersensitivity: Burosumab must be discontinued if serious hypersensitivity reactions occur and appropriate medical treatment should be initiated.
Excipient with known effect: This medicine contains 45.91 mg of sorbitol in each vial which is equivalent to 45.91 mg/ml.
Effects on ability to drive and use machines: Burosumab may have a minor influence on the ability to drive and use machines. Dizziness may occur following administration of burosumab.