Course of NTX changes under continuous bisphosphonate treatment in cases of NTX over-reduction due to long-term treatment with bisphosphonates.

Background It has recently been suggested that long-term continuous treatment with bisphosphonates can eventually result in skeletal harm. We reported that the level of urinary cross-linked N-telopeptide of type I collagen (NTX) was over-reduced in 11 of 87 (12.7%) patients receiving long-term therapy with bisphosphonates. In this case, it is inconclusive whether treatment with bisphosphonates should be continued or not after over-reduction of bone resorption markers. In this study, we demonstrated changes in NTX levels in 13 patients who consented to continue treatment with bisphosphonates even after the over-reduction of NTX levels.