Fosamax

Fos·a·max (fs-mks)

A trademark for the drug alendronate sodium.

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alendronate sodium

Fosamax

Pharmacologic class: Bisphosphonate

Therapeutic class: Bone-resorption inhibitor

Pregnancy risk category C

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

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

➣ Glucocorticoid-induced osteoporosis in adults with low bone mineral density who are receiving daily glucocorticoid doses equivalent to 7.5 mg or more of prednisone

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

➣ Osteoporosis in postmenopausal women; to increase bone mass in men with osteoporosis

Adults: 10 mg P.O. daily or 70 mg P.O. once weekly

Contraindications

• Hypersensitivity to bisphosphonates
• Hypocalcemia
• Renal insufficiency
• Esophageal abnormalities

Precautions

Use cautiously in:
• renal insufficiency, esophageal disease, GI ulcers, gastritis
• pregnant or breastfeeding patients
• children.

Administration

• Give with 6 to 8 oz of water before first food, beverage, or medication of day.
• Don't give food, other beverages, or oral drugs for at least 30 minutes after giving dose.
• Keep patient upright for at least 30 minutes after giving dose to avoid serious esophageal irritation.
• Be aware that aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs) may worsen GI upset. Discuss alternative analgesics with prescriber.

Route	Onset	Peak	Duration
P.O.	1 mo	3-6 mo	3 wk-7 mo

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

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Fosamax®

Alendronate, see there