Alendronate Sodium
Pronouncation: (al-LEN-droe-nate SO-dee-uhm)Class: Bisphosphonate
Trade Names:
Fosamax
- Tablets 5 mg
- Tablets 10 mg
- Tablets 35 mg
- Tablets 40 mg
- Tablets 70 mg
- Oral solution 70 mg (as base)
Pharmacology
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Inhibits bone resorption and increases bone density.
Pharmacokinetics
Absorption
Oral bioavailability is 0.64% (women) and 0.59% (men). Food decreases bioavailability significantly.
Distribution
Distributes to soft tissues, then rapidly to bone. Vd is at least 28 L (exclusive of bone); about 78% protein bound.
Metabolism
Not metabolized.
Elimination
About 50% excreted in urine within 72 h. The t ½ is more than 10 yr.
Special Populations
Renal Function ImpairmentElimination may be reduced. No dosage adjustment is necessary in those with mild to moderate renal function impairment. Alendronate is not recommended in those with severe renal function impairment (Ccr less than 35 mL/min).
Indications and Usage
Treatment of osteoporosis in postmenopausal women; prevention of osteoporosis in postmenopausal women at risk of developing osteoporosis; increase bone mass in men; treatment of glucocorticoid-induced osteoporosis in men and women; treatment of Paget disease of the bone.
Contraindications
Abnormalities of esophagus that delay esophageal emptying; inability to stand or sit upright for at least 30 min; patients at increased risk of aspiration (oral solution); hypocalcemia; hypersensitivity to any component of product.
Dosage and Administration
Osteoporosis (Postmenopausal Women)Adults (treatment)
PO 70 mg once weekly or 10 mg once daily.
Adults (prevention)PO 35 mg once weekly or 5 mg once daily.
Osteoporosis (Men)Adults
PO 70 mg once weekly or 10 mg once daily.
Glucocorticoid-Induced OsteoporosisAdults
PO 5 mg once daily. For postmenopausal women not receiving estrogen, 10 mg once daily.
Paget DiseaseAdults
PO 40 mg once daily for 6 mo. Re-treatment may be considered for patients who relapse after a 6-mo observation period.
General Advice
- Administer prescribed dose in the morning at least 30 min before the first food, beverage (other than water), or medication of the day.
- Have patient swallow tablet with a full glass (6 to 8 oz) of plain water and remain sitting or standing for at least 30 min.
- Have patient swallow oral solution directly from bottle, then drink at least 2 oz of plain water and remain standing or sitting for at least 30 min.
- Do not administer tablets or oral solution with any liquid other than plain water. Administration of alendronate with food, medication, juices, mineral water, coffee, or any other beverage will reduce alendronate absorption and efficacy.
Storage/Stability
Store tablets and oral solution at room temperature (59° to 86°F). Keep tablets in tightly closed container. Protect oral solution from freezing.
Drug Interactions
AspirinRisk of upper GI adverse reactions is increased by concomitant use of aspirin and alendronate doses over 10 mg/day.
Calcium supplements, antacids, other cationsDecreased alendronate absorption.
FoodAbsorption of alendronate is decreased by food.
LiquidsBeverages other than water decrease absorption.
NSAIDsRisk of GI irritation may be increased.
RanitidineIncreased alendronate absorption; clinical importance unknown.
Laboratory Test Interactions
None well documented.
Adverse Reactions
CNS
Headache (3%); malaise (postmarketing).
Dermatologic
Pruritus, rash (occasionally with photosensitivity), severe skin reactions including Stevens-Johnson syndrome and toxic epidermal necrolysis (postmarketing).
EENT
Episcleritis, scleritis, uveitis (postmarketing).
GI
Abdominal pain (7%); acid regurgitation, flatulence (4%); constipation, diarrhea, dyspepsia, nausea (3%); esophageal ulcer (2%); abdominal distention, dysphagia, gastric ulcer, gastritis (1%); duodenal ulcer, esophagitis, esophageal erosion, esophageal stricture or perforation, oropharyngeal ulceration (postmarketing).
Hypersensitivity
Hypersensitivity including urticaria, angioedema (postmarketing).
Lab Tests
Asymptomatic, mild, and transient decreases in serum calcium (18%) and phosphate (10%); symptomatic hypocalcemia (postmarketing).
Musculoskeletal
Muscular skeletal pain (4%); muscle cramp (1%); transient myalgia (postmarketing).
Miscellaneous
Fever (postmarketing).
Precautions
MonitorBone mineral densityEnsure that bone mineral density is measured before starting therapy and after 6 to 12 mo of treatment in patient with glucocorticoid-induced osteoporosis. Calcium/Vitamin DEnsure that patient's daily calcium and vitamin D intake are evaluated before starting therapy and that calcium and/or vitamin D supplementation is being used in patient with inadequate daily intake. Esophageal reactionMonitor patient for signs or symptoms of esophageal reaction (eg, dysphagia, retrosternal pain, new or worsening heartburn). Discontinue therapy and inform health care provider if noted or suspected. |
Pregnancy
Category C .
Lactation
Undetermined.
Children
Safety and efficacy not established.
Renal Function
Not recommended for patients with Ccr below 35 mL/min.
Absorption
Food, beverages other than water, and some medications inhibit absorption. Must be taken first thing in the morning with a full glass of water at least 30ߙmin before any food, beverages, or medications. Must remain sitting or standing for 30 min after taking.
GI disorders
Not recommended for patients with upper GI problems.
Hypocalcemia
Correct before starting alendronate.
Nutrition
Maintain adequate calcium and vitamin D intake during alendronate therapy.
Overdosage
Symptoms
Hypocalcemia, hypophosphatemia, upper GI adverse reactions.
Patient Information
- Advise patient to read patient package insert before starting therapy and to reread the insert each time the medication is renewed.
- Instruct patient to take each dose with plain water the first thing upon arising for the day, at least 30 min before first food, beverage, or medication of day, and to remain in a standing or sitting position for at least 30 min and until after their first food of the day.
- Instruct patient using tablet to swallow tablet whole with a full glass (6 to 8 oz) of plain water. Caution patient not to chew or suck on tablet.
- Instruct patient using oral solution to drink entire contents of bottle and then drink at least ¼ cup (2 oz) of water.
- Caution patient not to take alendronate with any other liquid than plain water. Advise patient that taking alendronate with food, other medications, juices, mineral water, coffee, or any other beverage will reduce the absorption of alendronate and reduce its efficacy.
- Advise patient taking alendronate once a week that if a dose is missed, to take dose the next morning, and then return to taking 1 dose a week as originally scheduled on chosen day. Caution patient not to take 2 doses on the same day to catch up.
- Instruct patient to discontinue therapy and seek medical care if any of the following occur: difficulty swallowing; pain behind breastbone; new or worsening heartburn.
- Advise patient regarding interventions that help prevent osteoporosis: 1,500 mg/day of calcium (diet and supplements); vitamin D supplementation; weight-bearing exercise; reduction of cigarette smoking and excessive alcohol consumption.
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More Alendronate Sodium resources:
Osteoporosis, Prevention of Osteoporosis, Paget's Disease








