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Bisphosphonate Therapy for Paget's Disease in a Patient with Hypoparathyroidism: Profound Hypocalcemia, Rapid Response, and Prolonged Remission
Author(s) -
Stuckey B. G. A.,
Lim E. M.,
Kent G. N.,
Ward L. C.,
Gutteridge D. H.
Publication year - 2001
Publication title -
journal of bone and mineral research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.882
H-Index - 241
eISSN - 1523-4681
pISSN - 0884-0431
DOI - 10.1359/jbmr.2001.16.9.1719
Subject(s) - medicine , calcitriol , bisphosphonate , hypoparathyroidism , liter , bone disease , urinary calcium , hyperparathyroidism , paget's disease of bone , endocrinology , urology , urinary system , gastroenterology , surgery , vitamin d and neurology , osteoporosis , disease
Bisphosphonate treatment for severe Paget's disease leads to hypocalcemia followed by a secondary hyperparathyroid response to restore normocalcemia. A case is presented of a 60‐year‐old woman with polyostotic Paget's disease and postsurgical hypoparathyroidism. In 1993 her Paget's disease—alkaline phosphatase (ALP), 1260 U/liter (35–135 U/liter), and fasting urinary hydroxyproline excretion, 13.7 μmol/liter GF (0.4–1.9 μmol/liter)—was treated with intravenous pamidronate. Symptomatic hypocalcemia followed the first 60‐mg dose, requiring large doses of calcium supplementation and calcitriol. Pamidronate therapy to a total dose of 360 mg was followed by rapid and prolonged remission with indices of bone turnover in the normal range within 2 months and persisting for at least 19 months after treatment. In 1999 relapse of Paget's disease—ALP, 511 U/liter (35–135 U/liter), and fasting urinary deoxypyridinoline/creatinine 53.1 μmol/mol (5–27 μmol/mol)—was treated with alendronate, 10 mg daily. Symptomatic hypocalcemia occurred again, requiring increased calcium and calcitriol therapy. Indices of bone turnover were within the normal range 9 weeks after the start of therapy. These responses were significantly more rapid and sustained than those observed in euparathyroid subjects. This case suggests that the lack of parathyroid response may modify the response to bisphosphonates by: (a) increasing intrinsic uptake of bisphosphonate into the pagetic skeleton, allowing response to a smaller dose; (b) increasing duration and severity of hypocalcemia after bisphosphonate therapy; and (c) removing the hyperparathyroid drive to reactivation of pagetic osteoclasts, leading to a prolonged remission. These observations have implications for optimizing bisphosphonate therapy both in Paget's disease and in osteoporosis.