Can Fosamax Be Started in a Man?
Yes, alendronate (Fosamax) should absolutely be started in men with osteoporosis—it is the first-line treatment for men at high risk of fracture. 1
Evidence-Based Recommendation
The most recent 2024 evidence-based guideline from Nature Reviews Rheumatology provides a strong recommendation that oral bisphosphonates (alendronate or risedronate) are first-line treatments for men at high risk of fracture 1. This is not a conditional or weak recommendation—it represents the highest level of consensus from the working group.
FDA Approval and Clinical Evidence
Alendronate is FDA-approved for treatment of osteoporosis in men 2. The FDA label specifically documents efficacy in men with hypogonadal or idiopathic osteoporosis through two pivotal clinical studies:
Daily dosing (10 mg): In 241 men aged 31-87 years, alendronate produced significant BMD increases at 2 years: lumbar spine +5.3%, femoral neck +2.6%, total body +1.6% (all p<0.001 vs placebo) 2
Weekly dosing (70 mg): In 167 men aged 38-91 years, once-weekly dosing showed similar efficacy at 1 year: lumbar spine +2.8%, femoral neck +1.9%, total body +1.2% 2
Critically, vertebral fracture incidence was significantly lower with alendronate (0.8% vs 7.1% with placebo, p=0.02) 3.
When to Initiate Treatment in Men
Based on the 2024 guideline, start alendronate when men meet these criteria 1:
- Prior fragility fracture (strong recommendation—all such men should be considered for treatment)
- High fracture risk based on FRAX assessment with age-dependent thresholds
- Osteoporosis diagnosis using female reference database for DXA (T-score ≤-2.5)
Dosing and Administration
- Standard regimen: 70 mg once weekly (equivalent efficacy to 10 mg daily) 2
- Must ensure: Vitamin D and calcium repletion in all men above age 65 (strong recommendation) 1
- Pre-treatment assessment: Consider checking serum total testosterone as part of evaluation 1
Safety Profile in Men
The FDA label and clinical trials demonstrate alendronate is generally well-tolerated in men 2:
- Discontinuation rates due to adverse events: 2.7-6.4% with alendronate vs 8.6-10.5% with placebo
- Most common adverse events: acid regurgitation, flatulence, gastroesophageal reflux, dyspepsia (all <5%)
- No significant difference in serious adverse events compared to placebo
Common Pitfall to Avoid
Do not assume osteoporosis treatment is only for women. The 2024 guideline specifically addresses that men often perceive osteoporosis as "just for old women," leading to poor adherence (up to 64% non-adherent by 12 months) 1. Patient education and counseling are essential when initiating therapy.
Second-Line Options
If alendronate is contraindicated or causes adverse effects, the 2024 guideline provides a strong recommendation for denosumab or zoledronate as second-line treatments 1. The 2023 American College of Physicians guideline similarly recommends denosumab as second-line (conditional recommendation) 4.
Very High-Risk Patients
For men at very high risk of fracture, consider sequential therapy starting with a bone-forming agent (teriparatide, abaloparatide) followed by an anti-resorptive agent like alendronate (strong recommendation) 1.