title: Promethazine inhibits osteoclastic bone resorption in vitro.
abstract: Several studies have shown that promethazine can reduce age-related osteopenia in mice. Furthermore, prolonged treatment with promethazine (50 mg/day) increases bone mineral content in the lumbar spine in post-menopausal women with osteopenia. However, the mechanism of action of promethazine has not been elucidated. The present study shows that promethazine HCl (0.01-10 microM) dose-dependently inhibits bone resorption by isolated rat osteoclasts in the bone slice assay with an IC50 of approximately 1 microM. Since these concentrations are likely to be achieved in vivo, it is suggested that the beneficial effect of promethazine on osteopenia is at least partly due to a direct inhibitory effect on osteoclast activity.
authors.affiliation: Ciba-Geigy Ltd., Research Department, Basel, Switzerland.
authors.forename: T J
authors.initials: TJ
authors.lastname: Hall
authors.forename: M
authors.initials: M
authors.lastname: Schaueblin
mesh_terms: D000375:Aging / Q000473:pathology; D000818:Animals; D015519:Bone Density / Q000187:drug effects*; D001851:Bone Diseases, Metabolic / Q000517:prevention & control*; D001862:Bone Resorption / Q000517:prevention & control*; D002478:Cells, Cultured; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D010010:Osteoclasts / Q000187:drug effects*; D011398:Promethazine / Q000494:pharmacology / Q000627:therapeutic use*; D051381:Rats
chemical_list: D011398:Promethazine