Fosamax

Action

Impedes bone resorption by inhibiting osteoclast activity, absorbing calcium phosphate crystal in bone, and directly blocking dissolution of hydroxyapatite crystal of bone

Availability

Tablets: 5 mg, 10 mg, 35 mg, 40 mg, 70 mg

Indications and dosages

➣ Paget's disease of bone (men and women)

Adults: 40 mg P.O. daily for 6 months

➣ Prevention of osteoporosis in postmenopausal women

Adults: 5 mg P.O. daily or 35 mg P.O. once weekly for up to 7 years

➣ Glucocorticoid-induced osteoporosis in men and women

Adults: 5 mg P.O. daily. For postmenopausal women not receiving estrogen, recommended dosage is 10 mg P.O. once daily.

➣ Treatment of osteoporosis in postmenopausal women; treatment to increase bone mass in men with osteoporosis

Adults: 70-mg tablet or 70 mg oral solution P.O. weekly or 10-mg tablet P.O. daily

Contraindications

• Hypersensitivity to drug or its components

• Hypocalcemia

• Esophageal abnormalities such as stricture or achalasia that delay esophageal emptying

• Inability to stand or sit upright for 30 minutes

• Increased risk of aspiration (oral solution)

Precautions

Use cautiously in:

• Severe renal insufficiency (creatinine clearance less than 35 ml/minute), esophageal disease, GI ulcers, gastritis, osteonecrosis of jaw

• pregnant or breastfeeding patients

• children.

Administration

• Give with 6 to 8 oz of water 30 minutes before first food, beverage, or medication of day.

• Don't give at bedtime or before patient arises for the day.

• Don't give food, other beverages, or oral drugs for at least 30 minutes after giving tablets.

• Keep patient upright for at least 30 minutes after giving dose to avoid serious esophageal irritation.

• Follow oral solution with at least 60 ml (2 oz) of water to facilitate gastric emptying.

• Be aware that patients should receive supplemental calcium and vitamin D if dietary intake is inadequate.

• Be aware that aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs) may worsen GI upset. Discuss alternative analgesics with prescriber.

Adverse reactions

CNS: headache

CV: hypertension

GI: nausea, vomiting, diarrhea, constipation, abdominal pain, acid regurgitation, esophageal ulcer, flatulence, dyspepsia, abdominal distention, dysphagia

GU: urinary tract infection

Hematologic: anemia

Metabolic: hypomagnesemia, hypophosphatemia, hypokalemia, fluid overload

Musculoskeletal: bone or muscle pain

Skin: rash, redness, photosensitivity

Other: abnormal taste

Interactions

Drug-drug. Antacids, calcium supplements: decreased alendronate absorption

NSAIDs, salicylates: increased risk of GI upset

Ranitidine: increased alendronate effect

Drug-diagnostic tests. Calcium, phosphate: decreased levels

Drug-food. Any food, caffeine (as in coffee, tea, cocoa), mineral water, orange juice: decreased drug absorption

Patient monitoring

• Monitor for signs and symptoms of GI irritation, including ulcers.

• Monitor blood pressure.

• Evaluate blood calcium and phosphate levels.

Patient teaching

☞ Tell patient to immediately report serious vomiting, severe chest or abdominal pain, difficulty swallowing, or abdominal swelling.

• Instruct patient to take tablets first thing in the morning on an empty stomach, with 6 to 8 oz of water only.

• Instruct patient to follow oral solution with at least 60 ml (2 oz) of water.

• Tell patient not to lie down, eat, drink, or take other oral medications for 30 minutes after taking dose.

• Advise patient to take only those pain relievers suggested by prescriber. Inform him that some over-the-counter pain medications (such as aspirin and NSAIDs) may worsen drug's adverse effects.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, and foods mentioned above.