Alendronate Sodium (4 brand names, 3 dosage forms, 1 route)
Available dosage forms: SOLUTION, TABLET, TABLET, EFFERVESCENT.
Routes of administration: ORAL.
Brand Names
- ALENDRONATE SODIUM
- BINOSTO
- FOSAMAX
- FOSAMAX PLUS D
Related Health Topics
Contraindications
Alendronate sodium tablets are contraindicated in patients with the following conditions: Inability to stand or sit upright for at least 30 minutes [see Dosage and Administration ( 2.6 ); Warnings and Precautions ( 5.1 )] Hypocalcemia [see Warnings and Precautions ( 5.2 )] Hypersensitivity to any component of this product. Hypersensitivity reactions including urticaria and angioedema have been reported [see Adverse Reactions ( 6.2 )].
Adverse Reactions
The following clinically significant adverse drug reactions are described elsewhere in the labeling: Upper Gastrointestinal Adverse Reactions [see Warnings and Precautions (5.1) Mineral Metabolism [see Warnings and Precautions (5.2)] Musculoskeletal Pain [see Warnings and Precautions (5.3)] Osteonecrosis of the Jaw [see Warnings and Precautions (5.4)] Atypical Fractures Including Femoral Fractures [see Warnings and Precautions (5.5)] Renal Impairment [see Warnings and Precautions (5.6)] Glucocorticoid-Induced Osteoporosis [see Warnings and Precautions (5.7)]
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 [ 3H]alendronate in bone showed about 10-fold higher uptake on osteoclast surfaces than on osteoblast surfaces. Bones examined 6 and 49 days after [ 3H]alendronate administration in rats and mice, respectively, showed that normal bone was formed on top of the alendronate, which was incorporated inside the matrix. While incorporated in bone matrix, alendronate is not pharmacologically active. Thus, alendronate must be continuously administered to suppress osteoclasts on newly formed resorption surfaces. Histomorphometry in baboons and rats showed that alendronate treatment reduces bone turnover (i.e., the number of sites at which bone is remodeled). In addition, bone formation exceeds bone resorption at these remodeling sites, leading to progressive gains in bone mass.
Overdosage
Significant lethality after single oral doses was seen in female rats and mice at 552 mg/kg (3256 mg/m 2) and 966 mg/kg (2898 mg/m 2), respectively. In males, these values were slightly higher, 626 and 1280 mg/kg, respectively. There was no lethality in dogs at oral doses up to 200 mg/kg (4000 mg/m 2). No specific information is available on the treatment of overdosage with alendronate sodium. Hypocalcemia, hypophosphatemia, and upper gastrointestinal adverse events, such as upset stomach, heartburn, esophagitis, gastritis, or ulcer, may result from oral overdosage. Milk or antacids should be given to bind alendronate. Due to the risk of esophageal irritation, vomiting should not be induced and the patient should remain fully upright. Dialysis would not be beneficial.