The Effect on Bone Mineral Density in Patients with Osteoporosis and Obesity of Once-weekly Treatment with Risedronate/Vitamin D3 Combined in a Single Pill for 12 Months: A Post-marketing Study

Several health authorities around the world propose conducting additional observational studies after controlled clinical trials as a part of the regulatory approval process of a drug for marketing. These studies, known as post-marketing surveillance studies, are intended give further insight into the safety, efficacy, and/or optimal use of the drug under the usual conditions of clinical practice. Limited post-marketing studies have been conducted on Risedronate. Therefore, the aim of this study was to evaluate and compare the effect of recent treatment with Risedronate (35 mg) and vitamin D3 (2800 IU) combined in a single pill on bone mineral density in female patients with postmenopausal osteoporosis. Patients were classified according to body mass index criteria. An open-label, observational, post-marketing surveillance study was conducted in a sample group of 345 osteoporosis patients. All patients were allocated according to CONSORT recommendations and treated for 12 months with the study drug. We considered overweight (144) and obese (116) patients as the intervention group and patients with normal weight (84) as the reference group. We excluded one underweight patient from the statistical analysis. Osteoporosis was detected using peripheral bone mineral densitometry. We calculated the number needed to treat for both improvement and no effect on bone mineral density, and we conducted the appropriate statistical analysis. In obese patients, the number needed to treat was 20 and 33, and for overweight patients, the corresponding number was 50 and 20. In conclusion, treatment with Risedronate (35 mg) and vitamin D3 (2800 IU) combined in a single pill showed the most favorable antiresorptive effect in obese osteoporotic patients. These data suggest that health authorities and clinicians should focus on implementing a clinical algorithm that includes screening and monitoring of osteoporotic patients with different body mass indices during treatment.