Can Fosamax (alendronate) be used to treat osteoporosis in patients with Crohn's disease?

Alendronate (Fosamax) for Osteoporosis in Crohn's Disease Patients

Yes, alendronate (Fosamax) can be prescribed for osteoporosis in patients with Crohn's disease, and is considered a first-line therapeutic option for these patients despite potential absorption concerns.

Rationale for Using Alendronate in Crohn's Disease

Patients with Crohn's disease have an increased prevalence of osteoporosis due to multiple factors:

• Inflammatory cytokines affecting bone metabolism
• Glucocorticoid therapy (major risk factor)
• Malnutrition and vitamin D deficiency
• Disease activity itself 1

Efficacy Evidence

Research specifically examining alendronate in Crohn's disease patients has shown:

• Alendronate 10mg daily increased lumbar spine BMD by 4.6% compared to a 0.9% decrease with placebo over 12 months 2
• Significant reduction in biochemical markers of bone turnover 2
• Adequate absorption despite intestinal disease - studies show urinary excretion of alendronate in Crohn's patients (0.5-0.6%) is comparable to patients without gut pathology 3

Administration Considerations

When prescribing alendronate for Crohn's patients:

• Must be taken on an empty stomach with a full glass of water (180-240 ml)
• Patient must remain upright for at least 30 minutes after taking
• No food or other medications during this period 4
• Recommend calcium (1,000-1,500 mg/day) and vitamin D (400-800 IU/day) supplements, but taken at least 2 hours after alendronate 4

Special Considerations for Crohn's Patients

• Absorption concerns: Despite theoretical concerns about reduced absorption in Crohn's disease, research shows adequate absorption and clinical efficacy 3
• Renal function: Contraindicated in severe renal impairment (GFR < 35 ml/min/1.73 m²) 4
• GI side effects: Monitor carefully as Crohn's patients may already have GI symptoms; alendronate can cause upper GI issues including abdominal pain, dyspepsia, and acid regurgitation 4
• Dental health: Complete any necessary dental work before starting therapy due to risk of osteonecrosis of the jaw 4

Monitoring Recommendations

• BMD measurements every 1-2 years during treatment 4
• Monitor for GI side effects, especially in patients with active Crohn's disease
• Assess for clinical improvement and reduction in fracture risk

Potential Pitfalls and Caveats

1. Absorption variability: While studies show adequate absorption overall, individual patients with severe small bowel disease or extensive resections may have unpredictable absorption 1, 3

2. Alternative routes: Consider parenteral bisphosphonates if concerns about absorption or GI side effects 1

3. Glucocorticoid management: Simultaneously work to minimize glucocorticoid exposure, as this is a major contributor to bone loss in Crohn's disease 5

4. Disease activity: Controlling Crohn's disease activity may itself help improve bone health 6

In conclusion, despite the theoretical concerns about absorption in Crohn's disease, evidence supports that alendronate is adequately absorbed, effective at increasing BMD, and should be considered a first-line option for treating osteoporosis in these patients.