Sequential ibandronate infusion beneficial in osteoporosis

Sequential therapy with monthly ibandronate infusions yields improvements in bone mineral density (BMD) and cortical bone microstructure of osteoporotic patients who have been treated with teriparatide, as shown in a study.

The analysis included 63 female patients with primary osteoporosis (mean age, 77.3 years; mean height, 147.7 cm; mean body mass index, 22.6 kg/m²). All women had received teriparatide for more than 12 months (mean, 18.6 months) and were subsequently put on a 1-mg monthly intravenous ibandronate regimen for 12 months.

About 62 percent of the population had a previous history of fragility vertebral fractures (11 thoracic, 15 lumbar, and 13 thoracolumbar vertebrae). The median dual-energy X-ray absorptiometry (DXA) T-scores were −2.7 for the lumbar spine, −2.0 for the total hip, and −2.5 for the femoral neck. The median tartrate-resistant acid phosphatase-5b (TRACP-5b) level was 469 mU/dL, while that of total type I procollagen-N-propeptide (P1NP) was 62.5 μg/L. The patients had vitamin D deficiency, with an average 25(OH) vitamin D level of 12.3 ng/mL.

At 12 months after sequential therapy initiation, the bone resorption marker TRACP-5b dropped by 39.5 percent, with 82.3 percent of the patients exhibiting levels within the normal limit. DXA results also showed marked BMD improvements, with an increase of 3.2 percent in the lumbar spine. Of note, 79.0 percent of the patients exhibited a BMD response, and 40.3 percent experienced an increase in BMD >5 percent.

Meanwhile, results for high-resolution peripheral quantitative CT revealed an increase in cortical thickness of the distal tibia of 2.6 percent. The cortical area grew by 2.5 percent, and the buckling ratio, an index of cortical instability, shrunk by 2.5 percent.

There were no marked changes observed in most parameters of the trabecular bone. On the other hand, the improvements in the cortical bone were observed in both the distal radius and tibia and were evident at 6 months after initiation of ibandronate.