Pharmacokinetic and Pharmacodynamic Characteristics of Ibandronate in Healthy Subjects

건강한 자원자에서 Ibandronate의 약동학 및 약력학적 특성에 관한 연구

Background: Ibandronate is a nitrogen-containing bisphosphonate and used for the treatment of hypercalcemia of malignancy and postmenopausal osteoporosis as a potent Inhibitor of osteoclast-mediated bone resorption. This study was performed to evaluate pharmacokinetic (PK) and pharmacodynamic (PD) characteristics of ibandronate after a single intravenous (iv) infusion in healthy subjects. Methods: The study was conducted as a double blinded, randomized, placebo controlled, parallel group study in twenty-six healthy Korean subjects (13 males and 13 females). Subjects were randomized into one of three treatment groups of 2 mg, 6 mg, or placebo, with 10, 10, and 6 subjects in each group, respectively. Blood and urine samples for PK assessments were collected till 24 hours after the start of a 60 minute iv infusion. For PD assessments, CTX (Type I Collagen-linked C-telopeptide) and NTX (Type I Collagen-linked N-telopeptide) were measured in both serum and urine until 4 days after the infusion. Results: The area under the concentration-time curves from time zero to infinity ($AUC_{0-\infty}$) were $333.4\;{\pm}\;46\;(Mean\;{\pm}\;SD)\;ng{\cdot}h/mL$ for the 2 mg group, and $939.1\;{\pm}\;267.1\;ng{\cdot}h/mL$ for the 6 mg group. The values of mean clearance were 6.1 L/h and 6.9 L/h in the 2 mg and 6 mg group, respectively. Four days after the infusion, urinary CTX was decreased by 71.5% (2 mg) and 93.5% (6 mg group) from baseline (both P < .001). Other PD parameters were also significantly decreased in active treatment groups compared with the placebo group. Conclusions: Pharmacokinetic parameters exhibited linear properties regrding dose. Pharmacodynamic parameters as markers of bone turnover were significanly decreased from baseline in the active treatment groups.