Alendronate

What it is and how it works

Mechanism of Action Animal studies have indicated the following mode of action. At the cellular level, alendronate shows preferential localization to sites of bone resorption, specifically under osteoclasts. The osteoclasts adhere normally to the bone surface but lack the ruffled border that is indicative of active resorption. Alendronate does not interfere with osteoclast recruitment or attachment, but it does inhibit osteoclast activity. Studies in mice on the localization of radioactive [ 3 H]alendronate in bone showed about 10-fold higher uptake on osteoclast surfaces than on osteoblast surfaces.

Indications

Alendronate sodium is a bisphosphonate indicated for: Treatment and prevention of osteoporosis in postmenopausal women ( 1.1 , 1.2 ) Treatment to increase bone mass in men with osteoporosis Treatment of glucocorticoid-induced osteoporosis Treatment of Paget's disease of bone Limitations of use: Optimal duration of use has not been determined. For patients at low- risk for fracture, consider drug discontinuation after 3 to 5 years of use. Treatment of Osteoporosis in Postmenopausal Women Alendronate sodium tablets, USP are indicated for the treatment of osteoporosis in postmenopausal women. In postmenopausal women, alendronate sodium tablets, USP increases bone mass and reduces the incidence of fractures, including those of the hip and spine (vertebral compression fractures). Prevention of Osteoporosis in Postmenopausal Women Alendronate sodium tablets, USP are indicated for the prevention of postmenopausal osteoporosis .

Dosage and administration (summary)

Treatment of osteoporosis in postmenopausal women and in men: 10 mg daily or 70 mg (tablet) once weekly. ( 2.1 , 2.3 ) Prevention of osteoporosis in postmenopausal women: 5 mg daily or 35 mg once weekly. Glucocorticoid-induced osteoporosis: 5 mg daily; or 10 mg daily in postmenopausal women not receiving estrogen. Paget's disease: 40 mg daily for six months. Instruct patients to: o Swallow tablets whole with 6-8 ounces plain water at least 30 minutes before the first food, drink, or medication of the day. o Not lie down for at least 30 minutes after taking alendronate sodium tablets and until after food.

Contraindications

Abnormalities of the esophagus which delay esophageal emptying such as stricture or achalasia Inability to stand/sit upright for at least 30 minutes ( 2.6 , 4 , 5.1 ) Hypocalcemia ( 4 , 5.2 ) Hypersensitivity to any component of this product ( 4 , 6.2 ) Alendronate sodium tablets are contraindicated in patients with the following conditions: Inability to stand or sit upright for at least 30 minutes Hypocalcemia Hypersensitivity to any component of this product.

Warnings and precautions

Upper Gastrointestinal Adverse Reactions can occur. Instruct patients to follow dosing instructions. Discontinue if new or worsening symptoms occur. Hypocalcemia can worsen and must be corrected prior to use. Severe Bone, Joint, Muscle Pain may occur. Discontinue use if severe symptoms develop. Osteonecrosis of the Jaw has been reported. Atypical Femur Fractures have been reported. Patients with new thigh or groin pain should be evaluated to rule out an incomplete femoral fracture.

Pregnancy

Pregnancy Risk Summary Available data on the use of alendronate sodium in pregnant women are insufficient to inform a drug-associated risk of adverse maternal or fetal outcomes. Discontinue alendronate sodium when pregnancy is recognized.

Storage and supply

How Supplied 70 mg Tablets Alendronate Sodium Tablets USP, 70 mg are white, capsule shaped, biconvex tablets debossed with 'C224' on one side and plain on the other side. NDC 68071-3771-5 Unit-of-use blister package of 15 Storage Store at 20°C to 25°C (68°F to77°F); excursions permitted to 15°C to 30°C (59°F to 86°F) .

Source: Alendronate Sodium (Alendronate Sodium) — US FDA prescribing information, 2025-01-14, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.