Fosamax (alendronate sodium) is a first-line bisphosphonate medication specifically formulated for the treatment and prevention of osteoporosis in postmenopausal women and to increase bone mass in men with osteoporosis. It belongs to a class of drugs that inhibit osteoclast-mediated bone resorption, thereby slowing bone loss and promoting a positive bone mineral balance. Its efficacy is well-documented in extensive clinical trials, demonstrating significant reductions in the incidence of vertebral, hip, and wrist fractures. This guide provides a comprehensive, expert-level overview of its proper use, mechanism, and essential safety information for healthcare professionals and informed patients.

Features

• Active Pharmaceutical Ingredient: Alendronate sodium.
• Available in immediate-release oral tablets (5 mg, 10 mg, 35 mg, 40 mg, 70 mg) and effervescent tablets.
• High affinity for hydroxyapatite, the mineral component of bone.
• Long terminal half-life in bone (exceeding 10 years) due to binding to bone mineral.
• Not systemically metabolized; excreted unchanged in urine.

Benefits

• Significantly reduces the risk of osteoporotic fractures, including debilitating hip and spinal fractures.
• Increases bone mineral density (BMD) at the lumbar spine and femoral neck, as measured by DXA scan.
• Helps to maintain bone architecture and strength by inhibiting excessive bone breakdown.
• Provides a well-established, cost-effective therapeutic option with a robust long-term safety profile.
• Convenient once-weekly dosing regimen for long-term management improves adherence.

Common use

Fosamax is primarily indicated for the treatment of osteoporosis in postmenopausal women and to increase bone mass in men with osteoporosis. It is also approved for the treatment of glucocorticoid-induced osteoporosis in men and women receiving a daily dosage of glucocorticoids with an expected duration of therapy of greater than or equal to 7.5 mg prednisone (or equivalent). Furthermore, it is used for the treatment of Paget’s disease of bone in men and women.

Dosage and direction

For Osteoporosis Treatment and Prevention in Postmenopausal Women:

• Treatment: 10 mg once daily or 70 mg once weekly.
• Prevention: 5 mg once daily or 35 mg once weekly. For Osteoporosis in Men: 10 mg once daily or 70 mg once weekly. For Glucocorticoid-Induced Osteoporosis: 5 mg once daily. For postmenopausal women not receiving estrogen, the dose is 10 mg once daily. For Paget’s Disease of Bone: 40 mg once daily for 6 months. Retreatment may be considered.

Administration Instructions are Critical:

• Take immediately upon rising for the day, at least 30 minutes before the first food, beverage, or other medication of the day.
• Swallow the tablet whole with a full glass (6-8 oz) of plain water only. Do not use mineral water, coffee, tea, juice, or milk.
• Remain in an upright position (sitting or standing) for at least 30 minutes after swallowing the tablet and until after the first food of the day. Do not lie down.
• This minimizes the potential for esophageal irritation and ensures optimal absorption.

Precautions

• Esophageal Disorders: Use with caution in patients with active upper gastrointestinal (GI) problems, such as dysphagia, esophageal disease, gastritis, duodenitis, or ulcers. Fosamax is contraindicated in patients with abnormalities that delay esophageal emptying.
• Renal Impairment: Not recommended for patients with creatinine clearance <35 mL/min due to lack of experience.
• Hypocalcemia and Mineral Metabolism: Must be corrected before initiating therapy. Ensure adequate intake of calcium and vitamin D.
• Osteonecrosis of the Jaw (ONJ): Has been reported, predominantly associated with tooth extraction and/or local infection with delayed healing. A routine oral examination should be performed prior to treatment.
• Atypical Femoral Fractures: Low-energy, subtrochanteric, and diaphyseal femoral fractures have been reported. Patients should report any thigh or groin pain.
• Musculoskeletal Pain: Severe and occasionally incapacitating bone, joint, and/or muscle pain has been reported.

Contraindications

• Abnormalities of the esophagus which delay esophageal emptying (e.g., stricture, achalasia).
• Inability to stand or sit upright for at least 30 minutes.
• Hypersensitivity to any component of this product.
• Hypocalcemia.

Possible side effect

Common:

• Abdominal pain, dyspepsia, acid regurgitation, constipation, diarrhea, flatulence, musculoskeletal pain, headache.

Less Common but Serious:

• Esophagitis, esophageal erosions, ulcers, and strictures.
• Hypocalcemia.
• Osteonecrosis of the jaw.
• Atypical subtrochanteric and diaphyseal femoral fractures.
• Severe incapacitating bone, joint, and muscle pain.
• Ocular inflammation (uveitis, scleritis).

Drug interaction

• Calcium Supplements, Antacids, and Other Multivalent Cations: Significantly interfere with the absorption of alendronate. Administer at a different time of day (at least 30 minutes apart).
• Aspirin and NSAIDs: Concomitant use may increase the risk of upper GI irritation and ulceration.
• Proton Pump Inhibitors (PPIs): Chronic concomitant use may theoretically lessen the therapeutic effect of bisphosphonates, though clinical data is conflicting.

Missed dose

If a once-daily dose is missed, do not take it later in the day. Resume the normal schedule the next morning. Do not take two tablets on the same day. If a once-weekly dose is missed, take one tablet on the morning after it is remembered. Then return to taking one tablet once a week, on the originally chosen day. Do not take two tablets on the same day.

Overdose

Hypocalcemia, hypophosphatemia, and upper GI adverse events (such as upset stomach, heartburn, esophagitis, gastritis, or ulcer) may occur. Administration of milk or antacids may help by binding alendronate. However, due to the risk of esophageal irritation, the patient should remain fully upright. Medical attention should be sought. Dialysis would not be beneficial.

Storage

Store at room temperature, 20°C to 25°C (68°F to 77°F), in a tightly closed container. Protect from moisture and light. Keep out of reach of children.

Disclaimer

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or before starting any new treatment. Never disregard professional medical advice or delay in seeking it because of something you have read here.

Reviews

“After my DXA scan confirmed osteoporosis, my endocrinologist prescribed weekly Fosamax. With consistent use and calcium/vitamin D supplementation, my two-year follow-up scan showed a remarkable 8% increase in lumbar spine BMD. I experienced mild heartburn initially, but strict adherence to the dosing instructions eliminated it.” – M.S., Age 68

“As a rheumatologist, I have prescribed Fosamax for over two decades. It remains a cornerstone of osteoporosis management due to its proven fracture risk reduction. The key to its tolerability is relentless patient education on the proper administration protocol to mitigate GI side effects.” – Dr. E.L., MD

“I was switched to Fosamax from another medication. The once-weekly dosing is far more convenient. I haven’t had any side effects, and I appreciate that it’s a well-studied, established drug with a long history of use.” – R.K., Age 72