A 65-year-old woman comes to the office due to osteoporosis that was recently diagnosed on a screening DXA. She feels well, eats a balanced diet, and gets regular exercise. Medical history is unremarkable, but the patient has a family history of osteoporosis in her mother and sister. Vital signs and physical examination are normal. Complete blood count and serum chemistry panel are normal. DXA reveals a T-score of −2.7 at the lumbar spine. The patient says, "I am interested in taking alendronate to prevent fractures. My sister takes it, and it kept her osteoporosis from getting worse." Which of the following tests should be performed prior to initiating this medication?

Question

A 65-year-old woman comes to the office due to osteoporosis that was recently diagnosed on a screening DXA.  She feels well, eats a balanced diet, and gets regular exercise.  Medical history is unremarkable, but the patient has a family history of osteoporosis in her mother and sister.  Vital signs and physical examination are normal.  Complete blood count and serum chemistry panel are normal.  DXA reveals a T-score of −2.7 at the lumbar spine.  The patient says, "I am interested in taking alendronate to prevent fractures.  My sister takes it, and it kept her osteoporosis from getting worse."  Which of the following tests should be performed prior to initiating this medication?

Quizplus · Accepted Answer

Explanation: 11ec2b69_c1d3_3f22_8f63_7d88c93e7272_MD0005_00 This patient has postmenopausal osteoporosis, confirmed with a DXA T-score of ≤−2.5. Most secondary causes of osteoporosis can be identified based on history, physical examination, and initial basic laboratory studies (eg, complete blood count, serum chemistry panel). Initial management should include weight-bearing exercise, avoidance of smoking and excessive alcohol, and adequate intake of calcium (≥1,200 mg/day) and vitamin D (≥800 IU/day), using supplements as necessary. In addition, osteoporosis diagnosed using DXA or a confirmed osteoporotic fracture warrants pharmacologic antiresorptive therapy; bisphosphonates (eg, alendronate, risedronate) are preferred for most patients. However, bisphosphates can cause hypocalcemia due to decreased bone resorption; this effect is more prominent with intravenous formulations but can occasionally occur with oral bisphosphonates. Therefore, a normal serum calcium level should be confirmed prior to treatment. In addition, vitamin D deficiency can increase the risk of hypocalcemia, and so total body stores should be assessed with a serum 25-hydroxyvitamin D level. (Choice B) Oral bisphosphonates carry a risk of medication-induced esophagitis. The risk can be minimized by taking the medication with a full glass of water and remaining upright for 30 minutes. Esophagography or endoscopy is warranted if symptoms develop but is not needed prior to treatment. (Choice C) Bisphosphonates are associated with a risk of osteonecrosis of the jaw, especially with high-dose intravenous agents. However, mandibular and maxillary imaging is needed only if symptoms develop. (Choice D) Cushing syndrome can cause secondary osteoporosis. However, the morning cortisol is often normal in patients with Cushing syndrome; nocturnal salivary cortisol, 24-hour urine cortisol, and an overnight dexamethasone suppression test are better screening tests. Although adrenal disorders should be considered in patients with premenopausal osteoporosis, testing is not routinely needed for postmenopausal women. (Choice E) Primary hyperparathyroidism is associated with accelerated bone loss. However, most patients have baseline hypercalcemia; testing with a parathyroid hormone level is not needed if serum calcium is normal. Educational objective: Bisphosphates can cause hypocalcemia due to decreased bone resorption. A normal serum calcium level should be confirmed prior to initiation of therapy. In addition, vitamin D deficiency can increase the risk of hypocalcemia; total body vitamin D stores should be assessed with a serum 25-hydroxyvitamin D level. References: 25 hydroxyvitamin D serum levels influence adequate response to bisphosphonate treatment in postmenopausal osteoporosis. (http://www.ncbi.nlm.nih.gov/pubmed/22487299)

A 65-Year-Old Woman Comes to the Office Due to Osteoporosis