Is it safe to take 50 grams of prunes daily with Fosamax (alendronate)?

Safety of Taking 50 Grams of Prunes Daily with Fosamax (Alendronate)

Yes, taking 50 grams of prunes daily with Fosamax (alendronate) is safe and may even be beneficial, as prunes provide calcium and vitamin D which should be optimized when using bisphosphonates, though the timing of administration requires careful attention to avoid interference with alendronate absorption.

Key Administration Requirements

Alendronate must be taken on an empty stomach with plain water at least 30 minutes before consuming any food or beverages 1, 2. This strict requirement is critical because:

• Alendronate has poor bioavailability that is further reduced by food 3
• Any food, including prunes, will significantly impair absorption if taken concurrently 2
• Patients must remain upright for at least 30 minutes after taking alendronate to reduce risk of esophageal irritation 1, 2

Recommended Timing Strategy

To safely combine these:

• Take alendronate first thing in the morning with a full glass of plain water 1, 2
• Wait at least 30 minutes (preferably longer) before eating anything, including prunes 1
• Consume the 50 grams of prunes after this waiting period 1
• Remain upright during the entire waiting period 1, 2

Nutritional Considerations Supporting Combined Use

Calcium and vitamin D intake should be optimized when taking bisphosphonates 1. The guidelines recommend:

• 1000-1200 mg of calcium daily from all sources 1
• 800-1000 IU of vitamin D daily 1
• Prunes can contribute to overall calcium intake and support bone health 1

Vitamin D deficiency must be corrected before starting bisphosphonates, particularly intravenous formulations, as hypocalcemia has been reported in vitamin D-deficient patients 1.

Important Safety Precautions with Alendronate

Gastrointestinal Considerations

• Oral bisphosphonates may cause esophageal irritation and dyspepsia 1
• Patients with esophageal emptying disorders should avoid oral bisphosphonates 1
• Postmarketing surveillance has reported rare cases of esophageal ulceration, typically associated with non-compliance with administration instructions 2, 3
• The evidence suggests alendronate may lead to little or no difference in gastrointestinal adverse events compared to placebo when taken correctly 4

Osteonecrosis of the Jaw (ONJ)

• The incidence of ONJ with bisphosphonates for osteoporosis treatment is very low (<1 per 10,000-100,000 patients) 1
• Dental examination and completion of necessary dental work should be considered before starting bisphosphonates 1
• Recent dental extractions are a consistent risk factor for ONJ 1
• Updated evidence shows zero incidents of ONJ in primary and secondary prevention trials 4

Renal Function

• Oral bisphosphonates have better renal safety profiles than intravenous formulations 1
• Intravenous bisphosphonates are generally not recommended when creatinine clearance is less than 30 mL/min 1

Clinical Efficacy Context

For context on why this combination matters:

• Alendronate 10 mg daily (or 70 mg weekly) reduces vertebral fractures by 45% in both primary and secondary prevention 5, 4
• In secondary prevention, alendronate reduces hip fractures by 53% and wrist fractures by 50% 5, 4
• Adequate calcium and vitamin D were part of medical treatment in all major bisphosphonate trials 1

Common Pitfalls to Avoid

• Do not take prunes or any food within 30 minutes of alendronate 1, 2
• Do not lie down within 30 minutes of taking alendronate 1, 2
• Do not take alendronate with anything other than plain water 1, 2
• Do not continue alendronate if severe esophageal symptoms develop 2, 3

Monitoring Recommendations

• Bone mineral density should be monitored every 1-2 years 6
• Serum calcium levels should be assessed regularly 6
• Compliance with administration instructions should be verified at follow-up visits 1
• Consider checking 25(OH)D levels to ensure vitamin D adequacy 1