Effects of teriparatide, alendronate, or both in women with postmenopausal osteoporosis.
BACKGROUND
Teriparatide increases both bone formation and bone resorption.


OBJECTIVE
We sought to determine whether combining teriparatide with an antiresorptive agent would alter its anabolic action.


METHODS
This was a randomized controlled trial conducted in a single university hospital.


METHODS
We randomized 93 postmenopausal women with low bone mineral density (BMD) to alendronate 10 mg daily (group 1), teriparatide 40 microg sc daily (group 2), or both (group 3) for 30 months. Teriparatide was begun at month 6.


METHODS
BMD of the lumbar spine, proximal femur, proximal radius, and total body was measured by dual-energy x-ray absorptiometry (DXA) every 6 months. Lumbar spine trabecular BMD was measured at baseline and month 30 by quantitative computed tomography. Serum osteocalcin, N-terminal propeptide of type 1 collagen, and N-telopeptide levels were assessed frequently. Women who had at least one repeat DXA scan on therapy were included in the analyses (n = 69).


RESULTS
DXA spine BMD increased more in women treated with teriparatide alone than with alendronate alone (18 +/- 11 vs. 7 +/- 4%; P < 0.001) or both (18+/-11 vs. 12 +/- 9%; P = 0.045). Similarly, femoral neck BMD increased more in women treated with teriparatide alone than with alendronate alone (11 +/- 5 vs. 4 +/- 4%; P < 0.001) or both (11 +/- 5 vs. 3 +/- 5%; P < 0.001). Quantitative computed tomography spine BMD increased 1 +/- 7, 61 +/- 31, and 24 +/- 24% in groups 1, 2, and 3 (P < 0.001 for all comparisons). Serum osteocalcin, N-terminal propeptide of type 1 collagen, and cross-linked N-telopeptides of type I collagen increased more with teriparatide alone than with both (P < 0.001 for each marker).


CONCLUSIONS
Alendronate reduces the ability of teriparatide to increase BMD and bone turnover in women.
Finkelstein
Joel S
JS
Department of Medicine, Endocrine Unit, Massachusetts General Hospital, Boston, Massachusetts 02114, USA. jfinkelstein@partners.org
Wyland
Jason J
JJ
Lee
Hang
H
Neer
Robert M
RM
D015502:Absorptiometry, Photon; D000368:Aged; D000369:Aged, 80 and over; D019386:Alendronate / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D045930:Anabolic Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood; D015519:Bone Density; D050071:Bone Density Conservation Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D001842:Bone and Bones / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000517:prevention & control*; D010349:Patient Compliance; D011795:Surveys and Questionnaires; D019379:Teriparatide / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*
D045930:Anabolic Agents; D015415:Biomarkers; D050071:Bone Density Conservation Agents; D019379:Teriparatide; D019386:Alendronate