A large prospective European cohort study of patients treated with strontium ranelate and followed up over 3 years.

Strontium ranelate has been available as an osteoporosis treatment in Europe since 2004. This article describes a large European observational survey of the use of strontium ranelate in clinical daily practice. A retrospective observational registry included 32,446 women consulting for postmenopausal osteoporosis in seven countries. Within the registry, 12,046 women were receiving strontium ranelate and were followed up over 3 years. The baseline characteristics of the follow-up cohort were similar to those of the whole registry cohort (age, 68.9 ± 10.3 years; body mass index, 25.6 ± 4.3 kg/m(2); lumbar spine T-score, -2.57 ± 0.85 SD; femoral neck T-score, -2.11 ± 0.86 SD). At baseline, 77 % of patients had at least one risk factor for osteoporosis, and 46 % had a previous history of osteoporotic fracture. Mean duration of follow-up was 32.0 ± 9.7 months, and treatment duration was 25.2 ± 13.7 months (24,956 patient-years of treatment). Persistence with strontium ranelate was 80 % at 1 year, 68 % at 2 years, and 64 % at 32 months; most patients (about 80 %) reported rarely omitting a dose. At least one emergent adverse event was reported in 2,674 (22 %) patients, most frequently gastrointestinal side effects. The crude incidence of venous thromboembolic events was 2.1/1,000 patient-years. No cases of hypersensitivity reactions, such as drug rash with eosinophilia and systemic symptoms (DRESS), Steven-Johnson syndrome, or toxic epidermal necrolysis, were reported. During follow-up, a fracture occurred in 890 patients (7 %); 429 of the fractures were nonvertebral fractures. Our observational survey over 32 months indicated good rates of adherence with strontium ranelate and confirmed its good safety profile in the management of postmenopausal osteoporosis.