What to monitor for bone loss when a patient is on oxcarbazepine, using Dual-Energy X-ray Absorptiometry (DEXA)?

From the Guidelines

When monitoring a patient on oxcarbazepine who requires DEXA scanning for bone loss, baseline DEXA scanning is recommended before starting treatment, with follow-up scans every 2-5 years depending on initial results and risk factors, as well as regular checks of sodium levels, complete blood count, liver function tests, and vitamin D levels 1.

Monitoring Parameters

The following parameters should be monitored:

• Sodium levels every 3-6 months to detect potential hyponatremia caused by oxcarbazepine
• Complete blood count periodically to detect potential leukopenia or thrombocytopenia
• Liver function tests, especially during the first few months of treatment
• Vitamin D and calcium levels annually, with supplementation as necessary

Bone Health

For bone health specifically:

• Baseline DEXA scanning is recommended before starting treatment
• Follow-up DEXA scans every 2-5 years depending on initial results and risk factors
• Patients should be counseled on lifestyle modifications to support bone health, including weight-bearing exercise, adequate calcium intake (1000-1200 mg daily), and vitamin D supplementation (800-1000 IU daily) 1

Bone Loss Prevention

Oxcarbazepine can accelerate bone loss through altered vitamin D metabolism and calcium homeostasis, making these monitoring parameters essential for preventing osteoporosis in long-term users.

• Consider bone-protective medications if significant bone loss is detected on DEXA scans 1.

Risk Factors

Risk factors for osteoporotic fracture include increasing age, female sex, post-menopause for women, hypogonadism or premature ovarian failure, low body weight, history of parental hip fracture, ethnic background, previous clinical or morphometric vertebral fracture, previous fracture due to minimal trauma, rheumatoid arthritis, current smoking, alcohol intake, low bone mineral density, vitamin D deficiency, low calcium intake, hyperkyphosis, falling, and immobilization, as well as long-term use of certain medications such as glucocorticoids, anticoagulants, anticonvulsants, aromatase inhibitors, cancer chemotherapeutic drugs, and gonadotropin-releasing hormone agonists 1.

From the FDA Drug Label

Musculoskeletal, connective tissue and bone disorders: There have been reports of decreased bone mineral density, osteoporosis and fractures in patients on long-term therapy with oxcarbazepine.

Monitoring for bone loss is recommended when a patient is on oxcarbazepine, as there have been reports of decreased bone mineral density, osteoporosis, and fractures in patients on long-term therapy.

• DEXA scan can be used to monitor bone mineral density. 2

From the Research

Monitoring Parameters for Patients on Oxcarbazepine

When monitoring patients on oxcarbazepine, the following parameters should be considered:

• Biochemical markers of bone metabolism, such as serum calcium, phosphate, bone alkaline phosphatase, parathyroid hormone, osteocalcin, insulin-like growth factor (IGF)-1, C-telopeptide, and Vitamin D3 levels 3, 4
• Bone mineral density (BMD) using DEXA (dual energy X-ray absorptiometry) method, particularly in patients with risk factors for osteoporosis 3, 5
• Serum sodium levels, especially in patients with renal disease or those taking medications that may lower serum sodium levels 6
• Hyponatremia (serum sodium <125 mmol/l) symptoms, as it can develop gradually during the first months of oxcarbazepine therapy 6

DEXA Scan Recommendations

DEXA scans are recommended for:

• Adults over the age of 65 5
• Post-menopausal women 5
• Patients with risk factors for osteoporosis, such as previous fractures 5
• Patients on long-term oxcarbazepine therapy, as it may have an effect on bone health 3, 4
• The frequency of DEXA scans can be every one to two years, depending on the patient's risk factors and bone health status 5

Additional Considerations

• Oxcarbazepine may have a negative effect on bone health, particularly in female patients, and regular assessment of biochemical markers and BMD is necessary 3, 4
• Patients on oxcarbazepine should be monitored for signs of osteoporosis, such as bone loss, abnormal mineralization, and fractures 4
• Preventative measures for osteoporosis, such as tailored exercise and sufficient intake of calcium and vitamin D, should be considered for patients on long-term oxcarbazepine therapy 5