Alendronate Starting Dosage
For treatment of established osteoporosis, start alendronate 70 mg once weekly, which is the standard first-line dosing regimen recommended by the American Academy of Family Physicians. 1, 2
Treatment Dosing for Osteoporosis
- Alendronate 70 mg once weekly is the preferred treatment regimen for postmenopausal women and men with established osteoporosis 1, 2
- This once-weekly dosing is therapeutically equivalent to the daily 10 mg regimen but offers superior convenience and likely better adherence 3
- The combination formulation of alendronate/cholecalciferol (Fosamax Plus D) 70 mg plus 2,800 IU or 5,600 IU vitamin D once weekly is also recommended 1
- Alternative daily dosing of 10 mg can be used if weekly dosing is not feasible 2
Prevention Dosing for Osteoporosis
- For prevention (not treatment) of osteoporosis in postmenopausal women, use alendronate 35 mg once weekly 1, 2
- Alternative daily prevention dosing is 5 mg daily 1, 2
Critical Contraindications to Check Before Starting
Before initiating alendronate at any dose, verify the patient does NOT have: 1
- GFR < 35 mL/min/1.73 m² - alendronate is contraindicated in significant renal impairment 1, 2
- Hypocalcemia - must be corrected before starting therapy 1
- Esophageal abnormalities that delay esophageal emptying 1
- Inability to stand or sit upright for at least 30 minutes 1
Essential Concurrent Supplementation
- Always prescribe calcium 1000-1200 mg/day and vitamin D 800 IU/day alongside alendronate to optimize therapeutic outcomes and prevent hypocalcemia 1
- Inadequate supplementation reduces treatment efficacy, as most clinical trials included 500-1000 mg calcium and 400-800 IU vitamin D daily 1
Special Population Considerations
Elderly Patients with Multiple Comorbidities
- Assess renal function before initiating therapy, as age-related decline may necessitate avoiding alendronate if GFR < 35 mL/min/1.73 m² 1
- The standard 70 mg weekly dose remains appropriate for elderly patients with normal renal function 1
Cancer Treatment-Induced Bone Loss
- Alendronate 70 mg once weekly is effective for this indication 2
Duration of Therapy Guidance
- After 5 years of continuous therapy, consider drug holidays or reassessment, as fracture protection may persist for up to 5 years after stopping 1
- The optimal duration is not definitively established, but there is a trend toward interrupting therapy after 5-10 years due to rare adverse effects with long-term use (atypical femur fractures, osteonecrosis of the jaw) 1
Common Pitfalls to Avoid
- Never prescribe alendronate to patients with GFR < 35 mL/min/1.73 m² - this is a critical contraindication 2
- Do not start alendronate without ensuring adequate calcium and vitamin D supplementation 1
- Avoid abrupt discontinuation without considering potential for rebound bone loss 2
- Ensure patients understand proper administration technique (take with water, remain upright for 30 minutes, take on empty stomach) to minimize esophageal adverse events 1