Short-term bone marker responses to teriparatide and strontium ranelate in patients with osteoporosis previously treated with bisphosphonates

Objective: To evaluate the responses of serum beta-CTX and osteocalcin in patients who were undergoing treatment with teriparatide or strontium ranelate (SR). Subjects and methods: We analyzed 14 patients (12 women and 2 men; mean age of 71 years) taking teriparatide, and 13 female patients (mean age of 70 years) taking SR; all the patients having previously been on bisphosphonates. Serum beta-CTX and osteocalcin levels were determined before and after the first and third months of teriparatide treatment and up to the fourth month of treatment with SR. Results: We observed an initial significant increase in osteocalcin levels during the first month (165%, p = 0.01) followed by a peak of beta-CTX (180%, p = 0.02) after the third month of treatment with teriparatide. An increase in these markers was also observed with SR: 49% in osteocalcin (p = 0.002) and 80% in beta-CTX (p = 0.008). Conclusion: SR had a predominantly short-term bone-forming effect in postmenopausal women with osteoporosis previously treated with bisphosphonates in a lesser degree than with teriparatide. Arq Bras Endocrinol Metab. 2010;54(2):244-9