Alendronate is FDA-approved for the treatment of postmenopausal osteoporosis, prevention of postmenopausal osteoporosis, steroid-induced osteoporosis, male osteoporosis, and Paget disease of the bone. Alendronate is an option for maintaining or increasing bone-mass, although risedronate is the preferred agent in men with osteoporosis.
Alendronate is not FDA-approved for use in Crohn-induced osteoporosis. Studies have evaluated the optimal treatment of Crohn-induced osteoporosis with evidence indicating the use of pamidronate infusions to avoid upper gastrointestinal (GI) adverse effects associated with oral alendronate. However, current evidence supports bisphosphonates as first-line therapy, administered orally, or parenterally.
Alendronate is not FDA-approved for use in osteopenia secondary to cystic fibrosis of the lung. A multicenter, randomized controlled trial with 56 participants conducted in Canada indicated alendronate therapy was well tolerated and improved bone mineral density over 12 months when compared to placebo. Alendronate demonstrated increased spine and femur bone mineral density in those with cystic fibrosis in an additional double-blinded trial.
Alendronate is not FDA-approved for use in fibrous dysplasia of the bone. Current data endorses the use of pamidronate in decreased bone remodeling measured through decreased serum alkaline phosphatase and urinary hydroxyproline, but no current studies support alendronate use.
Alendronate is not FDA-approved for use in growth hormone deficiency. A randomized controlled trial in osteoporotic adult-onset growth hormone deficiency demonstrated that the addition of alendronate therapy for 12 months provided no significant difference in bone turnover, bone mineral density, or prevalence of vertebral fractures. However, participants maintained on recombinant growth hormone in addition to alendronate indicated a significant decrease in bone turnover and an increase in bone mineral density of the lumbar spine. Further study is necessary to validate these results.
Alendronate is not FDA-approved to treat hypercalcemia of malignancy. Previously, bisphosphonates were the mainstay of treatment, but intravenous calcitonin has demonstrated superior efficacy. Current clinical guidelines indicate first-line therapy is aggressive intravenous hydration, followed by calcitonin. Two to four days post calcitonin therapy initiation, administer zoledronic acid, or ibandronate. Zoledronic acid is preferable to alendronate due to superior potency. If zoledronic acid is unavailable, ibandronate or pamidronate are other options.
Clinicians frequently employ alendronate in the treatment of male hypogonadism induced osteoporosis. A randomized controlled study of 22 osteoporotic men with long-standing hypogonadism demonstrated that femoral neck bone mineral density increased with long-term administration of alendronate along with testosterone replacement.
Rarely, alendronate is used off-label in pediatric populations with bone necrosis, hypervitaminosis D, and secondary amenorrhea. Due to the unknown teratogenic effect and the long half-life of bisphosphonates, there is not sufficient evidence to support bisphosphonate therapy in pediatric populations.