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Pronunciation |
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(a
LEN droe
nate) |

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U.S. Brand
Names |
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Fosamax® |

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Generic
Available |
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No |

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Synonyms |
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Alendronate Sodium |

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Pharmacological Index |
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Bisphosphonate Derivative |

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Use |
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Treatment of osteoporosis in postmenopausal women, Paget's disease of the
bone; treatment of glucocorticoid-induced osteoporosis in males and females with
low bone mineral density who are receiving a daily dosage greater than or equal
to 7.5 mg of prednisone (or equivalent) |

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Pregnancy Risk
Factor |
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C |

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Contraindications |
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Hypersensitivity to bisphosphonates or any component of the product;
hypocalcemia; abnormalities of the esophagus which delay esophageal emptying
such as stricture or achalasia; inability to stand or sit upright for at least
30 minutes |

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Warnings/Precautions |
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Use caution in patients with renal impairment; hypocalcemia must be corrected
before therapy initiation with alendronate; ensure adequate calcium and vitamin
D intake to provide for enhanced needs in patients with Paget's disease in whom
the pretreatment rate of bone turnover may be greatly
elevated. |

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Adverse
Reactions |
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Note: Incidence of adverse effects increases significantly in
patients treated for Paget's disease at 40 mg/day, mostly GI adverse effects
Central nervous system: Headache (2.6%); pain (4.1%)
Gastrointestinal: Flatulence (2.6%); acid regurgitation (2%); esophagitis
ulcer (1.5%); dysphagia, abdominal distention (1%)
<1%: Rash, erythema (rare), gastritis (0.5%) |

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Overdosage/Toxicology |
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Symptoms of overdose include hypocalcemia, hypophosphatemia; upper GI adverse
events (upset stomach, heartburn, esophagitis, gastritis or ulcer)
Treat with milk or antacids to bind alendronate; dialysis would not be
beneficial |

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Drug
Interactions |
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Ranitidine (by increasing gastric pH) can double the bioavailability of
alendronate |

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Mechanism of
Action |
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A bisphosphonate which inhibits bone resorption via actions on osteoclasts or
on osteoclast precursors; decreases the rate of bone resorption direction,
leading to an indirect decrease in bone formation |

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Pharmacodynamics/Kinetics |
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Absorption: Oral: Male: 0.6% given in a fasting state; Female: 0.7%
Protein binding: ~78%
Metabolism: Not metabolized
Bioavailability: Reduced up to 60% with food or drink
Half-life: Terminal: Exceeds 10 years; serum concentrations cleared >95%
in 6 hours
Elimination: Renal with unabsorbed drug eliminated in feces
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Usual Dosage |
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Oral: Alendronate must be taken with plain water first thing in the morning
and greater than or equal to 30 minutes before the first food, beverage, or
other medication of the day. Patients should be instructed to take alendronate
with a full glass of water (6-8 oz) and not lie down for at least 30 minutes to
improve alendronate absorption.
Osteoporosis in postmenopausal women:
Prophylaxis: 5 mg once daily
Treatment: 10 mg once daily
Paget's disease of bone: 40 mg once daily for 6 months
Retreatment: Relapses during the 12 months following therapy occurred in 9%
of patients who responded to treatment. Specific retreatment data are not
available. Retreatment with alendronate may be considered, following a 6-month
post-treatment evaluation period, in patients who have relapsed based on
increases in serum alkaline phosphatase, which should be measured periodically.
Retreatment may also be considered in those who failed to normalize their serum
alkaline phosphatase.
Treatment of glucocorticoid-induced osteoporosis: 5 mg once daily. A dose of
10 mg once daily should be used in postmenopausal women who are not receiving
estrogen. Patients treated with glucocorticoids should receive adequate amounts
of calcium and vitamin D.
Elderly: No dosage adjustment is necessary
Dosage adjustment in renal impairment:
Clcr 30-60 mL/minute: None necessary
Clcr <35 mL/minute: Alendronate is not recommended due to lack
of experience
Dosage adjustment in hepatic impairment: None necessary
|

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Dietary
Considerations |
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Ensure adequate calcium and vitamin D intake to provide for enhanced needs in
patients with Paget's disease in whom the pretreatment rate of bone turnover may
be greatly elevated. |

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Monitoring
Parameters |
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Alkaline phosphatase should be periodically measured; serum calcium,
phosphorus, and possibly potassium due to its drug class; use of absorptiometry
may assist in noting benefit in osteoporosis; monitor pain and fracture
rate |

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Reference Range |
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Calcium (total): Adults: 9.0-11.0 mg/dL (2.05-2.54 mmol/L), may slightly
decrease with aging; phosphorus: 2.5-4.5 mg/dL (0.81-1.45
mmol/L) |

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Mental Health: Effects
on Mental Status |
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None reported |

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Mental Health:
Effects on Psychiatric
Treatment |
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None reported |

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Dental Health: Local
Anesthetic/Vasoconstrictor
Precautions |
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No information available to require special precautions |

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Dental Health:
Effects on Dental Treatment |
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No effects or complications reported |

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Patient
Information |
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Take as directed, with a full glass of water. Stay in sitting or standing
position for 30 minutes following administration to reduce potential for
esophageal irritation. Avoid aspirin- or aspirin-containing medications. Consult
prescriber to determine necessity of lifestyle changes or dietary supplements of
calcium or dietary vitamin D. You may experience GI upset (eg, flatulence,
bloating, nausea, acid regurgitation); small frequent meals may help. Report
acute headache or gastric pain, unresolved GI upset, or acid stomach.
Pregnancy/breast-feeding precautions: Inform prescriber if you are or intend
to be pregnant. Consult prescriber if breast-feeding. |

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Nursing
Implications |
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Patients should be instructed that the expected benefits of alendronate may
only be obtained when each tablet is administered with plain water the first
thing in the morning and at least 30 minutes before the first food, beverage, or
medication of the day. Also instruct them that waiting >30 minutes will
improve alendronate absorption. Even dosing with orange juice or coffee markedly
reduces the absorption of alendronate.
Patients should be instructed to take alendronate with a full glass of water
(6-8 oz 180-240 mL) and not to lie down (stay fully upright sitting or standing)
for at least 30 minutes following administration to facilitate delivery to the
stomach and reduce the potential for esophageal irritation.
Patients should be instructed to take supplemental calcium and vitamin D if
dietary intake is inadequate. Consider weight-bearing exercise along with the
modification of certain behavioral factors, such as excessive cigarette smoking
or alcohol consumption if these factors exist. |

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Dosage Forms |
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Tablet, as sodium: 5 mg, 10 mg, 40 mg |

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References |
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Chesnut CH 3rd, McClung MR, Ensrud KE, et al,
"Alendronate Treatment of the Postmenopausal Osteoporatic Woman: Effect of Multiple Dosages on Bone Mass and Bone Remodeling,"
Am J Med, 1995, 99(2):144-52.
Watts NB, "Treatment of Osteoporosis With Bisphosphonates," Rheum Dis Clin
North Am, 1994, 20(3):717-34. |

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