The effect of alendronate on renal tubular reabsorption of phosphate

Bone Miner. 1994 Oct;27(1):51-6. doi: 10.1016/s0169-6009(08)80186-9.

Abstract

We report the effects of alendronate on phosphate homeostasis in two patients. In a woman with postmenopausal osteoporosis, the infusion of alendronate (7.5 mg intravenously daily for 4 consecutive days) was not associated with secondary hyperparathyroidism despite a reduction in serum calcium. This was associated with a rise in serum phosphate and TmP/GFR. This response contrasted with those observed in 14 other patients with osteoporosis, in whom PTH rose significantly following the infusion of alendronate in association with a significant fall in serum phosphate and TmP/GFR. The second patient, a woman with Paget's disease, was treated with intravenous alendronate (10 mg daily for 5 consecutive days) on two occasions for relapse of disease activity. On the first occasion there was a 150% rise in serum PTH associated with a fall in serum phosphate and TmP/GFR. On the second occasion, when the rise in serum PTH was less marked, there was a rise in serum phosphate and TmP/GFR. We conclude that alendronate may increase renal tubular reabsorption of phosphate, but that this effect is usually offset by secondary hyperparathyroidism.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absorption / drug effects
  • Aged
  • Alendronate
  • Calcium / blood
  • Diphosphonates / administration & dosage
  • Diphosphonates / pharmacology*
  • Diphosphonates / therapeutic use
  • Female
  • Glomerular Filtration Rate / drug effects
  • Homeostasis / drug effects
  • Humans
  • Hyperparathyroidism, Secondary / blood
  • Hyperparathyroidism, Secondary / etiology
  • Injections, Intravenous
  • Kidney Tubules / drug effects*
  • Kidney Tubules / metabolism
  • Osteitis Deformans / blood
  • Osteitis Deformans / drug therapy*
  • Osteitis Deformans / metabolism
  • Osteoporosis, Postmenopausal / blood
  • Osteoporosis, Postmenopausal / drug therapy*
  • Osteoporosis, Postmenopausal / metabolism
  • Parathyroid Hormone / blood
  • Phosphates / blood
  • Phosphates / metabolism*

Substances

  • Diphosphonates
  • Parathyroid Hormone
  • Phosphates
  • Calcium
  • Alendronate