alendronate sodium
(ah len' dro nate)
Fosamax

Pregnancy Category C

Drug classes
Bisphosphonate
Calcium regulator

Therapeutic actions
Slows normal and abnormal bone resorption without inhibiting bone formation and mineralization.

Indications
· Treatment and prevention of osteoporosis in postmenopausal women
· Treatment of men with osteoporosis
· Treatment of glucocorticoid-induced osteoporosis
· Treatment of Paget's disease of bone in patients with alkaline phosphatase at least two times upper limit of normal, those who are symptomatic, those at risk for future complications

Contraindications and cautions
· Contraindicated withallergy to biphosphonates; hypocalcemia, pregnancy, lactation.
· Use cautiously with renal dysfunction, upper GI disease.

Available forms
Tablets--5, 10, 35, 40, 70 mg

Dosages
ADULTS
· Postmenopausal osteoporosis: 10 mg/day PO in AM with full glass of water, at least 30 min before the first beverage, food, or medication of the day, or 70 mg PO once a week.
· Males with osteoporosis: 10 mg/day PO.
· Prevention of osteoporosis: 5 mg/day PO or 35 mg PO once a week.
· Paget's disease: 40 mg/day PO in AM with full glass of water, at least 30 min before the first beverage, food, or medication of the day for 6 mo; may retreat after 6-mo treatment-free period.
· Glucocorticoid-induced osteoporosis: 5 mg/day PO with calcium and vitamin D.
PEDIATRIC PATIENTS
Safety and efficacy not established.
PATIENTS WITH RENAL IMPAIRMENT
Dosage adjustment not necessary for creatinine clearance 35–60 mL/min; not recommended if creatinine clearance < 35 mL/min.

Pharmacokinetics
Route
Onset
Duration
PO
Slow
Days


Metabolism: Not metabolized
Distribution: Crosses placenta; may enter breast milk
Excretion: Urine

Adverse effects
· CNS: Headache
· GI: Nausea, diarrhea
· Skeletal: Increased or recurrent bone pain, focal osteomalacia

Interactions
Drug-drug
· Increased risk of GI distress with aspirin
· Decreased absorption if taken with antacids, calcium, iron, multivalent cations; separate dosing by at least 30 min
Drug-food
· Significantly decreased absorption and serum levels if taken with food; separate dosing from food and beverage by at least 30 min

Nursing considerations
CLINICAL ALERT!
Name confusion has occurred between Fosamax (alendronate) and Flomax (tamsulosin); use caution.

Assessment
· History: Allergy to bisphosphonates, renal failure, upper GI disease, lactation, pregnancy
· Physical: Muscle tone, bone pain; bowel sounds; urinalysis, serum calcium

Interventions
· Give in AM with full glass of water at least 30 min before the first beverage, food, or medication of the day. Patient must stay upright for 30 min.
· Monitor serum calcium levels before, during, and after therapy.
· Recommend concomitant hormone replacement therapy in treatment of osteoporosis.
· Ensure 6-mo rest period after treatment for Paget's disease if retreatment is required.
· Ensure adequate vitamin D and calcium intake.
· Provide comfort measures if bone pain returns.

Teaching points
· Take drug in morning with a full glass of plain water (not mineral water), at least 30 min before any beverage, food, or medication, and stay upright for 30 min.
· These side effects may occur: nausea, diarrhea; bone pain, headache (analgesic may help).
· Report twitching, muscle spasms, dark-colored urine, severe diarrhea.

Adverse effects in Italic are most common; those in Bold are life-threatening.