A Prospective Open‐Label Observational Study of a Buffered Soluble 70 mg Alendronate Effervescent Tablet on Upper Gastrointestinal Safety and Medication Errors: The GastroPASS Study

Upper gastrointestinal (GI) side effects are a main reason for discontinuing bisphosphonate treatment, an important therapeutic option for osteoporosis patients. Consequently, the development of novel formulations with improved tolerability is warranted. In this multicenter prospective, observational, postauthorization safety study conducted in Italy and Spain, postmenopausal women (PMW) with osteoporosis (naïve to bisphosphonates) were treated weekly with a buffered soluble alendronate 70 mg effervescent (ALN‐EFF) tablet (Binosto®) and followed for 12 ± 3 months. Information was collected on adverse events (AEs), medication errors, persistence, and compliance using the Morisky‐Green questionnaire. Patients (N = 1028) aged 67 ± 9 years (mean ± SD) received ALN‐EFF weekly. The cumulative incidence of upper GI AEs (oesophageal toxicity, gastritis, gastric ulcers, and duodenitis) related to ALN‐EFF (primary endpoint) was 9.6% (95% confidence interval [CI] 7.9–11.6%), the vast majority being of mild intensity. The most frequently occurring upper GI AEs related to ALN‐EFF were dyspepsia (2.7%), gastroesophageal reflux disease (2.4%), and nausea (2.2%). None of the relevant upper GI AEs listed in the primary endpoint and no serious AEs were reported. At least one medication error occurred in 29.9% (95% CI 27.1–32.8%) of patients. However, the majority of medication errors were associated with administration instructions applicable to any oral bisphosphonate and only seven medication errors were associated with the ALN‐EFF formulation. ALN‐EFF was discontinued in 209 of 1028 (20.3%) patients. The most frequent reasons for discontinuation were AEs related to ALN‐EFF (46.9%) and patients' decision (42.6%). Compliance with ALN‐EFF was high, reflected by a mean Morisky‐Green score of 92.8 ± 18.6. PMW with osteoporosis treated with ALN‐EFF in a real‐world setting experienced few upper GI AEs. In addition, they had a low discontinuation and high compliance compared with other formulations, suggesting that ALN‐EFF may increase patient satisfaction and therefore long‐term adherence and efficacy. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.