title: Comparison of treatment effects of teriparatide and the bisphosphonate risedronate in an aged, osteopenic, ovariectomized rat model under various clinical conditions.
abstract: Teriparatide and bisphosphonates are osteoporosis medications that increase bone mineral density (BMD) and prevent fracture, but each has a different mechanism of action. Teriparatide promotes bone formation, while bisphosphonates suppress bone resorption. In the clinical setting, however, drug selection is not always tailored to the particular clinical condition of the patient or mechanism of action of the drug. We compared the effects of teriparatide and the bisphosphonate risedronate on bone metabolism using two ovariectomized rat models to elucidate the optimal use of these two drugs in the clinical setting. We first performed dose-finding experiments to determine the equivalent effective doses of each drug (5.6 and 3.0 µg/kg for teriparatide and risedronate, respectively). We then compared the effects of these doses on bone metabolism after subcutaneous administration three times weekly for 4 months starting either the day after ovariectomy (preventive study) or 12 months after ovariectomy (therapeutic study). The increase in proximal tibial BMD under the physical conditions that increased bone turnover at 1 to 2 months after ovariectomy was greater in the risedronate group than in the teriparatide group. In contrast, the increases in lumbar vertebral BMD and bone strength under the physical conditions that significantly decreased BMD and bone strength at 12 months after ovariectomy were greater in the teriparatide group than in the risedronate group. The present study provides important information on the selection of antiosteoporotic drugs, including teriparatide and risedronate, in treatment protocols tailored to the clinical conditions of patients and drug mechanisms.
authors.affiliation: Pharmaceuticals Research Center, Asahi Kasei Pharma Corporation, 632-1 Mifuku, Izunokuni, Shizuoka, 410-2321, Japan. sugie.ab@om.asahi-kasei.co.jp.
authors.forename: Ayano
authors.initials: A
authors.lastname: Sugie-Oya
authors.affiliation: Pharmaceuticals Research Center, Asahi Kasei Pharma Corporation, 632-1 Mifuku, Izunokuni, Shizuoka, 410-2321, Japan.
authors.forename: Aya
authors.initials: A
authors.lastname: Takakura
authors.affiliation: Pharmaceuticals Research Center, Asahi Kasei Pharma Corporation, 632-1 Mifuku, Izunokuni, Shizuoka, 410-2321, Japan.
authors.forename: Ryoko
authors.initials: R
authors.lastname: Takao-Kawabata
authors.affiliation: Pharmaceuticals Research Center, Asahi Kasei Pharma Corporation, 632-1 Mifuku, Izunokuni, Shizuoka, 410-2321, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Sano
authors.affiliation: Pharmaceuticals Research Center, Asahi Kasei Pharma Corporation, 632-1 Mifuku, Izunokuni, Shizuoka, 410-2321, Japan.
authors.forename: Yukari
authors.initials: Y
authors.lastname: Shimazu
authors.affiliation: Pharmaceuticals Research Center, Asahi Kasei Pharma Corporation, 632-1 Mifuku, Izunokuni, Shizuoka, 410-2321, Japan.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Isogai
authors.affiliation: Department of Oral Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Yamaguchi
authors.affiliation: Pharmaceuticals Research Center, Asahi Kasei Pharma Corporation, 632-1 Mifuku, Izunokuni, Shizuoka, 410-2321, Japan.
authors.forename: Toshinori
authors.initials: T
authors.lastname: Ishizuya
mesh_terms: D000375:Aging; D000818:Animals; D001851:Bone Diseases, Metabolic / Q000188:drug therapy* / Q000209:etiology / Q000378:metabolism; D004195:Disease Models, Animal; D005260:Female; D008159:Lumbar Vertebrae / Q000378:metabolism*; D010052:Ovariectomy; D051381:Rats; D017207:Rats, Sprague-Dawley; D000068296:Risedronic Acid / Q000494:pharmacology*; D019379:Teriparatide / Q000494:pharmacology*
chemical_list: D019379:Teriparatide; D000068296:Risedronic Acid
keywords: Drug mechanism; Ovariectomized rat; Risedronate; Teriparatide; Three times weekly