Examples:
(1) phenytoin: increased metabolism of vitamin D
(2) ifosfamide: renal tubular damage and phosphate wastage in the urine
(3) furosemide: interference with bone mineralization
Steps:
(1) Identify the medications associated with a potential for osteomalacia.
(2) If possible, discontinue the medication or switch therapy to an alternative that does not affect bone, If not able to change, then use the lowest dose possible and treat for the shortest period to achieve the therapeutic goals.
(3) Treat comorbid conditions that may contribute to the osteomalacia.
(3a) Gastrointestinal diseases affecting absorption of calcium and phosphate.
(3b) Renal diseases associated with calcium or phosphorus wastage.
(3c) Diseases affecting metabolism of vitamin D.
(4) Monitor those factors affected by the medication in serum and urine:
(4a) 25-hydroxy vitamin D (absorption and metabolism)
(4b) calcium (absorption and excretion)
(4c) phosphate (absorption and excretion)
(5) Administer nutritional supplements to reverse or prevent deficiencies.
(5a) Oral supplements are often sufficient but may need to be significant.
(5b) Parenteral supplements may be necessary if there is a process interfering with absorption.
(5c) The dose required for prevention is usually less than for replacement.
