Skeletal Retention of Bisphosphonate (Pamidronate) and Its Relation to the Rate of Bone Resorption in Patients With Breast Cancer and Bone Metastases

Bisphosphonate pharmacokinetics may affect individual responses. Skeletal retention of pamidronate infused monthly to patients with bone metastases was highly variable (12‐98%) and did not diminish with time, showing the capacity of the skeleton to retain large amounts of bisphosphonate. Relationships between skeletal retention of pamidronate and rate of bone resorption are complex and depend on previous treatment and the total amount of retained bisphosphonate.