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Fosamax (ALENDRONIC ACID)
Fosamax works by inhibiting bone resorption, allowing bone density to increase.
At a glance
| Generic name | ALENDRONIC ACID |
|---|---|
| Sponsor | Merck And Co Inc |
| Drug class | Vitamin D [EPC] |
| Target | Farnesyl pyrophosphate synthase |
| Modality | Small molecule |
| Therapeutic area | Bone |
| Phase | FDA-approved |
| First approval | 1995 |
Mechanism of action
Mechanism of Action. Animal studies have indicated the following mode of action. At the cellular level, alendronate shows preferential localization to sites of bone resorption, specifically under osteoclasts. The osteoclasts adhere normally to the bone surface but lack the ruffled border that is indicative of active resorption. Alendronate does not interfere with osteoclast recruitment or attachment, but it does inhibit osteoclast activity. Studies in mice on the localization of radioactive [3H]alendronate in bone showed about 10-fold higher uptake on osteoclast surfaces than on osteoblast surfaces. Bones examined and 49 days after [3H]alendronate administration in rats and mice, respectively, showed that normal bone was formed on top of the alendronate, which was incorporated inside the matrix. While incorporated in bone matrix, alendronate is not pharmacologically active. Thus, alendronate must be continuously administered to suppress osteoclasts on newly formed resorption surfaces.
Approved indications
- Glucocorticoid Induced Osteoporosis
- Hypogonadal Osteoporosis in Males
- Osteitis deformans
- Postmenopausal osteoporosis
- Prevention of Glucocorticoid-Induced Osteoporosis
Common side effects
- Abdominal distention
- Abdominal pain
- Musculoskeletal (bone, muscle, joint) pain
- Nausea
- Dyspepsia
- Acid regurgitation
- Constipation
- Diarrhea
- Flatulence
- Gastritis
- Gastric ulcer
- Muscle cramp
Key clinical trials
- A Phase II Trial of RAB001 (LLP2A-Alendronate) for Steroid-Induced Early-Stage Osteonecrosis of the Femoral Head (PHASE2)
- Romosozumab Effects on Bone Density, Muscle Mass, and Spine Surgery Outcomes (PHASE2)
- Prospective, Randomized, Multicenter Clinical Trial of Bisphosphonates Combined With Vancomycin for the Treatment of Cierny-Mader Type I and III Osteomyelitis (PHASE3)
- Alendronate for Osteonecrosis in Adults With Sickle Cell Disease (PHASE2)
- Bone, Exercise, Alendronate, and Caloric Restriction (PHASE4)
- Alendronate to Reduce Pelvic Insufficiency Fractures in Cervical Cancer Patients Undergoing Chemoradiation (PHASE1,PHASE2)
- Bone Turnover Markers and Treatment Efficacy in Postmenopausal Osteoporosis (NA)
- The Optimal Sequential Therapy After Long Term Denosumab Treatment (PHASE4)
Patents
| Patent | Expiry | Type |
|---|---|---|
Primary sources
Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.
| Source | Used for |
|---|---|
| FDA label | Mechanism, indications, dosing, boxed warnings, drug interactions |
| ClinicalTrials.gov | Trial enrolment, design, endpoints, results |
| FDA Orange Book | Patents + exclusivity |
Competitive intelligence
For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:
- Fosamax CI brief — competitive landscape report
- Fosamax updates RSS · CI watch RSS
- Merck And Co Inc portfolio CI