Alendronate Sodium Drug Facts

Alendronate Sodium

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

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

Elimination 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

PO 70 mg once weekly or 10 mg once daily.

PO 35 mg once weekly or 5 mg once daily.

PO 70 mg once weekly or 10 mg once daily.

PO 5 mg once daily. For postmenopausal women not receiving estrogen, 10 mg once daily.

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

Risk of upper GI adverse reactions is increased by concomitant use of aspirin and alendronate doses over 10 mg/day.

Decreased alendronate absorption.

Absorption of alendronate is decreased by food.

Beverages other than water decrease absorption.

Risk of GI irritation may be increased.

Increased 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

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 30 min 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.