Deferasirox at therapeutic doses is associated with dose-dependent hypercalciuria

Area of Science:

• Nephrology
• Hematology
• Pharmacology

Background:

• Deferasirox is a widely used oral iron chelator for transfusion-dependent hemoglobinopathies.
• While initially considered renally safe, recent reports suggest potential renal tubular dysfunction and hypercalciuria.
• Urolithiasis and bone density loss have also been observed in patients on deferasirox.

Purpose of the Study:

• To investigate the prevalence of hypercalciuria in adult patients with transfusion-dependent hemoglobinopathies treated with deferasirox.
• To assess the relationship between deferasirox dosage and urinary calcium levels.
• To compare hypercalciuria rates between deferasirox and deferoxamine users.

Main Methods:

• A cross-sectional cohort study included 152 adult patients with various hemoglobinopathies.
• Patients were matched with healthy controls based on age, gender, and serum creatinine.
• Urine calcium to creatinine ratios (UCa/Cr) were measured to assess hypercalciuria.

Main Results:

• 91.9% of patients on deferasirox exhibited hypercalciuria, showing a positive dose-dependent relationship.
• Deferasirox use was associated with a nearly 4-fold increase in UCa/Cr at a mean dose of 30.2±8.8mg/kg/day.
• Hypercalciuria was not observed in patients treated with deferoxamine.

Conclusions:

• Hypercalciuria is common in patients treated with deferasirox for hemoglobinopathies.
• The dose-dependent nature of hypercalciuria with deferasirox warrants increased vigilance for potential complications.
• Further research is needed to understand the long-term implications of deferasirox-induced hypercalciuria, including risks for osteoporosis and urolithiasis.