Abstract
OBJECTIVE The aim of the study was to assess adding vs. switching to teriparatide 20 microg/d in patients on alendronate or raloxifene. DESIGN We conducted a randomized, open-label trial. PATIENTS AND INTERVENTIONS Postmenopausal women with osteoporosis on alendronate or raloxifene for at least 18 months added teriparatide (Add groups) or switched to teriparatide (Switch groups) for 18 months. MAIN OUTCOME MEASURES We measured bone turnover markers (BTM) and bone mineral density (BMD). RESULTS In the alendronate stratum, increases in BTM were smaller in the Add vs. Switch group [6-month PINP (64 vs. 401%); bone ALP (15 vs. 71%); betaCTX (27 vs. 250%); all P < 0.001]. However, at 6 months, total hip BMD increased more in the Add vs. Switch group (1.4 vs. -0.8%; P = 0.002). In the Add vs. Switch group, 18-month BMD increments were higher in lumbar spine (8.4 vs. 4.8%; P = 0.003) and total hip (3.2 vs. 0.9%; P = 0.02), but not in femoral neck (2.7 vs. 2.3%; P = 0.75). In the raloxifene stratum, increases in BTM were also smaller in the Add vs. Switch group [6-month PINP (131 vs. 259%; P < 0.001), bone ALP (31 vs. 44%; P = 0.035), and betaCTX (67 vs. 144%; P = 0.001)]. At 6 months, total hip BMD increase was greater in the Add vs. Switch group (1.8 vs. 0.5%; P = 0.028). At 18 months, increases in lumbar spine (9.2 vs. 8.1%), total hip (2.8 vs. 1.8%), and femoral neck (3.8 vs. 2.2%) were not significantly different between groups. CONCLUSIONS In women with osteoporosis treated with antiresorptives, greater bone turnover increases were achieved by switching to teriparatide, whereas greater BMD increases were achieved by adding teriparatide.
