Adherence to bisphosphonates and hormone replacement therapy in a tertiary care setting of patients in the CANDOO database

Abstract

Therapies for osteoporosis must be taken for at least 1 year to be effective. The purpose of this study was to determine the difference in adherence to etidronate, alendronate and hormone replacement therapy in a group of patients seen at our tertiary care centres. The Canadian Database of Osteoporosis and Osteopenia (CANDOO), a prospective observational database designed to capture clinical data, was searched for patients who started therapy following entry into CANDOO. There were 1196 initiating etidronate, 477 alendronate and 294 hormone replacement therapy women and men aged (mean, SD) 65.8 (8.7) years in the study. A Cox proportional hazards regression model was used to assess differences between treatment groups in the time to discontinuation of therapy. Several potential covariates such as anthropometry, medications, illnesses, fractures and lifestyle factors were entered into the model. A forward selection technique was used to generate the final model. Hazard ratios and 95% confidence intervals (CI) were calculated. Adjusted results indicated that alendronate-treated patients were more likely to discontinue therapy as compared with etidronate-treated patients (1.404; 95% CI: 1.150, 1.714). After 1 year, 90.3% of patients were still taking etidronate compared with 77.6% for alendronate. No statistically significant differences were found between hormone replacement therapy and etidronate users (0.971; 95% CI: 0.862, 1.093) and hormone replacement therapy and alendronate users (0.824; 95% CI: 0.624, 1.088) after controlling for potential covariates. After 1 year, 80.1% of patients were still taking hormone replacement therapy, which decreased to 44.5% after 6 years. Increasing age and presence of incident non-vertebral fractures were found to be independent predictors of adherence. In conclusion, alendronate users were more likely to discontinue therapy than etidronate users over the follow-up period. Potential barriers to long-term patient adherence to osteoporosis therapies need to be evaluated.

Monthly Oral Ibandronate Is Well Tolerated and Efficacious in Postmenopausal Women: Results From the Monthly Oral Pilot Study

“…The AUC 0-ϱ for the 50-and 100-mg ibandronate doses was consistent with prior phase I PK studies of oral ibandronate (37). As previously stated, recent studies have shown that therapeutic adherence with osteoporosis medications, including daily and weekly oral bisphosphonates, is suboptimal (12)(13)(14)(15)(16)(17)(18). Commonly cited reasons for nonadherence include dosing convenience and/or complexity (38,39) and side effects (38 -40).…”

“…Indeed, recent studies indicate that both compliance and persistence with current osteoporosis medications are suboptimal (12)(13)(14)(15)(16)(17)(18). A negative impact on therapeutic outcomes has also been observed, with nonadherent patients showing smaller increases in bone mineral density (BMD) (16,17), smaller decreases in bone turnover (17,19), and reduced antifracture efficacy (15,18) compared with adherent counterparts.…”

Canadian Consensus Conference on Osteoporosis, 2006 Update

“…[113][114][115] Increasing age and the presence of non-vertebral fractures have been found to be independent predictors of adherence in postmenopausal women. 116 To minimize the risk for esophagitis, patients must take bisphosphonates on an empty stomach with a full glass of water, then remain upright and avoid food, beverage, and other medications for 30 minutes. Patients who have mechanical problems of the esophagus, renal dysfunction (creatinine clearance < 30 mL/min), hypersensitivity to the drug, or suffer from hypocalcemia should avoid bisphosphonates.…”

Cost-effectiveness of Denosumab for the treatment of postmenopausal osteoporosis

“…Adherence to medication is low in osteoporosis and as problematic, if not worse, than in other chronic diseases [5,6]. An attractive feature of the 6-monthly regimen with denosumab is that adherence may be improved compared to alternative treatments, thereby improving effectiveness in clinical practice, resulting in more fractures avoided.…”