Ocular Toxicity: Retinal pigment epithelial detachment (RPED) occurs in 9% of patients; baseline and serial optical coherence tomography (OCT) evaluations every 2-3 months are required.

Critical Safety Monitoring and Contraindications

Hyperphosphatemia: Serum phosphate >5.5 mg/dL necessitates dietary phosphate restriction, binders, or dose adjustments; levels >10 mg/dL may require treatment interruption. Embryo-Fetal Risk: Contraception is mandatory for patients of reproductive potential during and for 1 week post-treatment. Drug Interactions: Avoid dual P-gp/CYP3A modulators (e.g., itraconazole, rifampin). Hepatic impairment (bilirubin >1.5×ULN) may increase toxicity risk. Lactation is contraindicated.