LAUSR

We interest the recent article by Everts-Graber and colleagues regarding the higher risk of osteonecrosis of the jaw (ONJ) under denosumab compared to bisphosphonates (BPs) in patients with osteoporosis. (1) It was also reported that the risk of developing ONJ in patients with cancer and bone metastases was signi fi cantly higher in the denosumab group than in the zoledronic acid group. (2,3) Teriparatide has been considered an effective therapeutic modality for medication-related ONJ in previous reports. (4-6) However, there are certain concerns about using teriparatide for the treatment of ONJ and osteoporosis thereafter in patients who have developed denosumab-related ONJ. Leder and colleagues (7) reported that switching therapy from denosumab to teriparatide resulted in transient bone loss at the spine and hip (over the fi rst 6 months and 12 months, respectively) and pro-gressive bone loss at the radius shaft. This risk of bone loss makes teriparatide unsuitable for the treatment of denosumab-related ONJ in patients with osteoporosis. Treatment of osteoporosis after the development of ONJ is also highly problematic in patients who have been treated with denosumab. Denosumab should be discontinued when ONJ develops. Because many patients experience a rebound effect of multiple vertebral fractures after the discontinuation of denosumab, (8) immediate sub-sequent therapy with a BP is strongly recommended. (9) However, BPs cannot be used in patients with ONJ. Teriparatide is not avail-able either because of the aforementioned risk of bone loss. it is