Objective: To evaluate the effects of discontinuing or continuing alendronate (ALN) therapy on bone mineral density (BMD) after patients on a long-term regimen of glucocorticoids (GCs) completed a 1-year treatment period with ALN.
Methods: Eligible patients were individuals with GC-induced osteoporosis who had received ALN (5 or 10 mg) for 1 year in a prior clinical trial and, at the end of the year, were still taking GCs at an average daily dose of > or =7.5 mg of prednisone or equivalent. Patients were contacted 3-5 years after completion of the prior ALN trial for followup measurements of the lumbar spine BMD and hip BMD, and retrospective information was collected about serious or drug-related adverse experiences and concomitant medication use. Some patients remained on GCs, and some remained on ALN, either alone or in combination with other drugs. The primary response parameter was the percentage change in lumbar spine BMD from the end of year 1 to the followup visit. Change in BMD at the hip was a secondary response parameter.
Results: Ninety (49.2%) of the eligible 183 patients participated in the retrospective study. The followup period, which began at the end of year 1 of the original clinical trial, ranged from 3.3 years to 4.6 years. The mean number of days of treatment with ALN was 507. Fifty patients were included in the analysis because they had received supraphysiologic doses of GCs (doses above the lowest tertile of GC use for the study population; that is, higher than approximately 6 mg/day), and they had not taken (defined as <6 months of use) other bone-affecting agents except ALN. Eleven of the 50 patients discontinued taking ALN (duration of use <90 days), 8 took ALN between 90 days and 300 days, and 31 continued to take ALN for >300 days after year 1 of the clinical trial. GC users who discontinued treatment with ALN (<90 days of therapy) had numerically greater decreases in BMD at the lumbar spine, femoral neck, and total hip from the end of year 1 (mean change -5.1%, -9.2%, and -6.6%, respectively), compared with patients who continued to take ALN for >300 days (mean change 0.1%, -0.9%, and 1.8%, respectively).
Conclusion: Substantial loss of BMD in the lumbar spine and hip was seen in patients who discontinued treatment with ALN but who continued to take >6 mg/day of GCs. However, patients receiving GCs who remained on the ALN regimen appeared to benefit from continued ALN treatment, since BMD was maintained in this latter group.