Contraindications to Fosamax (Alendronate)
Fosamax (alendronate) is absolutely contraindicated in patients with abnormalities of the esophagus, inability to stand or sit upright for at least 30 minutes, hypocalcemia, and hypersensitivity to any component of the product. 1, 2
Specific Contraindications
- Esophageal abnormalities that delay esophageal emptying such as stricture or achalasia 2, 1
- Inability to stand or sit upright for at least 30 minutes after taking the medication 2, 1
- Hypocalcemia must be corrected before initiating therapy 2, 1
- Hypersensitivity to alendronate or any component of the formulation (reactions may include urticaria and angioedema) 1
- Patients at increased risk of aspiration should not receive alendronate solution 2
Clinical Considerations and Relative Contraindications
Renal impairment: While not an absolute contraindication for oral alendronate, caution should be exercised in patients with renal dysfunction. Intravenous bisphosphonates are generally not recommended in patients with creatinine clearance less than 30 mL/min 2
Active upper gastrointestinal problems: Patients with active upper GI issues should be evaluated carefully before starting alendronate due to the risk of esophagitis 3, 4
Recent dental surgery: Consider delaying initiation in patients who have recently undergone dental procedures or extractions due to the rare risk of osteonecrosis of the jaw 2
Vitamin D deficiency: Should be corrected before initiating bisphosphonate therapy to avoid hypocalcemia, especially with intravenous formulations 2
Mechanism of Adverse Effects
Alendronate can cause chemical esophagitis, including severe ulcerations in some patients, particularly when not taken as directed 3
Studies have shown that alendronate 10 mg (the dose used for osteoporosis treatment) can cause gastric mucosal damage in 38% of subjects compared to 13% in placebo groups 5
The risk of esophagitis appears to be associated with:
- Swallowing alendronate with little or no water
- Lying down during or after ingestion of the tablet
- Continuing to take alendronate after onset of symptoms
- Pre-existing esophageal disorders 3
Administration Requirements to Minimize Adverse Effects
Patients must take alendronate with 180-240 mL (6-8 oz) of water on arising in the morning 3
Patients must remain upright for at least 30 minutes after swallowing the tablet and until after consuming their first food of the day 3
The medication should be discontinued promptly if esophageal symptoms develop 3
Patients should not take the medication at bedtime or before getting up for the day 2, 3
By following proper administration guidelines, the risk of upper GI adverse effects can be significantly reduced, making alendronate an effective first-line therapy for osteoporosis when not contraindicated 6.