Alendronic acid is indicated for:

• Treatment of Osteoporosis in Postmenopausal Women: It helps increase bone density and lowers the risk of fractures, especially in the hip and spine.
• Prevention of Osteoporosis in Postmenopausal Women: It is used to prevent bone loss after menopause.
• Treatment to Increase Bone Mass in Men with Osteoporosis: It improves bone strength in men suffering from osteoporosis.
• Treatment of Glucocorticoid-Induced Osteoporosis: Used in men and women taking long-term glucocorticoids (equivalent to ≥7.5 mg prednisone daily) who have low bone density.
• Treatment of Paget’s Disease of Bone: Indicated for patients with Paget’s disease, especially those with elevated alkaline phosphatase levels, symptoms, or risk of complications.

Alendronate is a bisphosphonate that binds strongly to bone mineral (hydroxyapatite) and inhibits osteoclast activity, thereby reducing bone resorption. Although it does not directly stimulate bone formation, overall bone formation may decrease secondary to reduced bone turnover.

At the cellular level, alendronate localizes to sites of active bone resorption beneath osteoclasts and inhibits their function without affecting their attachment. It does not interfere with osteoclast recruitment but reduces their activity significantly. Studies have shown greater uptake of alendronate on osteoclast surfaces compared to osteoblasts.

Alendronate becomes incorporated into the bone matrix and remains inactive while embedded. Continuous administration is necessary to suppress osteoclast activity at newly forming resorption sites. Over time, bone remodeling decreases, and bone formation exceeds resorption at these sites, resulting in increased bone mass.

Treatment of Osteoporosis in Postmenopausal Women: The recommended dosage is one 70 mg tablet once weekly or one bottle of 70 mg oral solution once weekly or one 10 mg tablet once daily.

Prevention of Osteoporosis in Postmenopausal Women: The recommended dosage is one 35 mg tablet once weekly or one 5 mg tablet once daily.

Treatment to Increase Bone Mass in Men with Osteoporosis: The recommended dosage is one 70 mg tablet once weekly or one bottle of 70 mg oral solution once weekly or one 10 mg tablet once daily.

Treatment of Glucocorticoid-Induced Osteoporosis: The recommended dosage is one 5 mg tablet once daily, except for postmenopausal women not receiving estrogen, for whom the recommended dosage is one 10 mg tablet once daily.

Treatment of Paget's Disease of Bone: The recommended treatment regimen is 40 mg once a day for six months.

The risk of upper gastrointestinal side effects may increase when Alendronic acid is used together with non-steroidal anti-inflammatory drugs (NSAIDs) or aspirin. Its absorption can be reduced when taken with antacids or calcium supplements.

Alendronic acid should not be used in patients with the following conditions:

• Esophageal disorders that delay emptying, such as stricture or achalasia
• Inability to remain upright (standing or sitting) for at least 30 minutes
• Oral solution should not be given to patients at high risk of aspiration
• Hypocalcemia
• Known hypersensitivity to any ingredient of the product, including reactions such as urticaria or angioedema

Common side effects include constipation, diarrhea, esophageal irritation or ulcer, gas, difficulty swallowing, musculoskeletal pain, headache, and occasionally rash or redness. It may also cause temporary reductions in calcium and phosphate levels, nausea, vomiting, peptic ulcer, and hypersensitivity reactions such as urticaria and angioedema.

Alendronic acid should not be used in pregnant or breastfeeding women.

• Upper gastrointestinal side effects may occur; patients should strictly follow dosing instructions. Stop treatment if new or worsening symptoms appear.
• Hypocalcemia may worsen and should be corrected before starting therapy.
• Severe bone, joint, or muscle pain can develop; discontinue the drug if symptoms become intense.
• Cases of osteonecrosis of the jaw have been reported.
• Unusual femur fractures have been observed; patients with new thigh or groin pain should be evaluated for possible incomplete fractures.

Pediatric Use: Alendronic acid is not recommended for children.

Renal Impairment: Not advised in patients with creatinine clearance below 35 mL/min. No dose adjustment is required for creatinine clearance between 35–60 mL/min.

Hepatic Impairment: Since alendronate is not metabolized or excreted via bile, no dose adjustment is necessary in liver impairment.

Bisphosphonate preparations.

Store in a tightly closed container at room temperature (15–30°C).