Alendronate Sodium

Synthetic bisphosphonate; bone resorption inhibitor.1 2 3 4 112

Osteoporosis

Prevention of osteoporosis in postmenopausal women1 24 25 with risk factors for development of osteoporosis.1 41 46 47 50 51 52 53 62 Risk factors include premature ovarian failure; family history of osteoporosis; small, slim body frame; endocrine disorders (e.g., thyrotoxicosis, hyperparathyroidism, Cushing’s syndrome, hyperprolactinemia, insulin-dependent diabetes mellitus); cigarette smoking; excessive alcohol use; sedentary lifestyle; low body weight; moderately low body mass; low dietary calcium intake; and Caucasian or Asian race.1 41 46 47 50 51 52 53 62

Used alone or in fixed combination with cholecalciferol (vitamin D3) for treatment of osteoporosis in postmenopausal women.1 2 3 5 6 7 8 10 11 12 13 112

Used alone or in fixed combination with cholecalciferol for treatment of osteoporosis in men.1 66 70 112

Alendronate/cholecalciferol fixed combination is not recommended for treatment of vitamin D deficiency.112 116

Alendronate has been used concomitantly with hormone replacement therapy.1 68 69

Corticosteroid-induced Osteoporosis

Treatment of corticosteroid-induced osteoporosis in men or women receiving corticosteroids (daily dosage equivalent to ≥7.5 mg of prednisone) who have low bone mineral density.1 57 58 73 78 110

Also used for prevention of corticosteroid-induced osteoporosis†.57 58 73 78 110

The American College of Rheumatology (ACR) currently recommends use of one of several bisphosphonates (i.e., alendronate, risedronate, or zoledronic acid) in conjunction with lifestyle modification and calcium and vitamin D supplementation for the prevention† and treatment of corticosteroid-induced osteoporosis† in select postmenopausal women and men ≥50 years of age who are initiating or currently receiving corticosteroid therapy.110

ACR recommendations based on a risk-stratification approach in which an individual’s clinical risk for developing a fracture is determined based on variables such as gender, age, race/ethnicity, and femoral neck density111 and the individual’s preexisting or anticipated corticosteroid dosage.110

ACR states that because of limited data, use of bisphosphonates for prevention† or treatment of corticosteroid-induced osteoporosis† in premenopausal women and men <50 years of age can be recommended only in those who have a history of fragility fracture.110

Paget’s Disease of Bone

Treatment of moderate to severe Paget’s disease of bone (osteitis deformans) in patients with serum alkaline phosphatase concentrations ≥ twice ULN or who are symptomatic or at risk for future complications.1 15

Antacids or Mineral Supplements Containing Divalent Cations

Potential decreased alendronate absorption when administered with divalent cations (e.g., calcium).1 112

Other Oral Medications

Potential decreased alendronate absorption when administered concomitantly with other oral medications.117 Administer alendronate ≥30 minutes prior to other oral medications.117

Specific Drugs

Absorption

Bioavailability

Oral bioavailability of alendronate in women and men is 0.64 and 0.59%, respectively.1 112

Bioavailability of alendronate sodium tablets and oral solution equivalent.1

Bioavailability of conventional tablets and fixed-combination tablets containing cholecalciferol (2800 and 5600 units) equivalent.112

Onset

Decrease in bone resorption rate evident as early as 1 month.1 112

Food

Alendronate bioavailability decreased by 40% when administered 0.5–1 hour prior to a meal, and by 60% when administered with coffee or orange juice.1 112 Bioavailability is negligible whether administered with or up to 2 hours after a meal.1 112

Distribution

Extent

Alendronate is widely distributed after oral administration.114 Subsequently, redistributes rapidly to skeletal tissues.112 114 Mean steady-state volume of distribution, exclusive of bone, is ≥28 L.1 112 114

Plasma Protein Binding

Alendronate: Approximately 78%.1 112

Elimination

Metabolism

No evidence of metabolism of alendronate.1 114

Elimination Route

Urinary excretion is the sole means of elimination of alendronate.1 3 112 113

Half-life

Terminal half-life of alendronate >10 years, reflecting release from bone.1 2 3 4 11 112

Special Populations

In patients with renal impairment, clearance of alendronate likely to be reduced.1 112 Somewhat greater accumulation in bone expected.1 112

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

Alendronate (Fosamax) for the treatment of Paget’s disease of bone is available only through Paget’s Patient Support Program with Pharma Care Specialty Pharmacy (800-238-7828 ext. 58197) distribution system for the 40-mg dosage regimen.115

If you take alendronate once daily: If you forget to take this medicine first thing in the morning, do not take it later in the day. Wait until the following morning to take the medicine and skip the missed dose. Do not take two (2) tablets in one day.

If you take alendronate once a week: If you forget to take alendronate on your scheduled day, take it first thing in the morning on the day after you remember the missed dose. Then return to your regular weekly schedule on your chosen dose day. Do not take two (2) tablets in one day.

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.

Treatment Of Osteoporosis In Postmenopausal Women

The safety of FOSAMAX in the treatment of postmenopausal osteoporosis was assessed in four clinical trials that enrolled 7453 women aged 44-84 years. Study 1 and Study 2 were identically designed, three-year, placebo-controlled, double-blind, multicenter studies (United States and Multinational n=994); Study 3 was the three-year vertebral fracture cohort of the Fracture Intervention Trial [FIT] (n=2027) and Study 4 was the four-year clinical fracture cohort of FIT (n=4432). Overall, 3620 patients were exposed to placebo and 3432 patients exposed to FOSAMAX. Patients with preexisting gastrointestinal disease and concomitant use of non-steroidal anti-inflammatory drugs were included in these clinical trials. In Study 1 and Study 2 all women received 500 mg elemental calcium as carbonate. In Study 3 and Study 4 all women with dietary calcium intake less than 1000 mg per day received 500 mg calcium and 250 international units Vitamin D per day.

Among patients treated with alendronate 10 mg or placebo in Study 1 and Study 2, and all patients in Study 3 and Study 4, the incidence of all-cause mortality was 1.8% in the placebo group and 1.8% in the FOSAMAX group. The incidence of serious adverse event was 30.7% in the placebo group and 30.9% in the FOSAMAX group. The percentage of patients who discontinued the study due to any clinical adverse event was 9.5% in the placebo group and 8.9% in the FOSAMAX group. Adverse reactions from these studies considered by the investigators as possibly, probably, or definitely drug related in greater than or equal to 1% of patients treated with either FOSAMAX or placebo are presented in Table 1.

Table 1: Osteoporosis Treatment Studies in Postmenopausal Women Adverse Reactions Considered Possibly, Probably, or Definitely Drug Related by the Investigators and Reported in Greater Than or Equal to 1% of Patients

Rash and erythema have occurred.

Gastrointestinal Adverse Reactions: One patient treated with FOSAMAX (10 mg/day), who had a history of peptic ulcer disease and gastrectomy and who was taking concomitant aspirin, developed an anastomotic ulcer with mild hemorrhage, which was considered drug related. Aspirin and FOSAMAX were discontinued and the patient recovered. In the Study 1 and Study 2 populations, 49-54% had a history of gastrointestinal disorders at baseline and 54-89% used nonsteroidal anti-inflammatory drugs or aspirin at some time during the studies. [See WARNINGS AND PRECAUTIONS]

Laboratory Test Findings: In double-blind, multicenter, controlled studies, asymptomatic, mild, and transient decreases in serum calcium and phosphate were observed in approximately 18% and 10%, respectively, of patients taking FOSAMAX versus approximately 12% and 3% of those taking placebo. However, the incidences of decreases in serum calcium to less than 8.0 mg/dL (2.0 mM) and serum phosphate to less than or equal to 2.0 mg/dL (0.65 mM) were similar in both treatment groups.

The safety of FOSAMAX 70 mg once weekly for the treatment of postmenopausal osteoporosis was assessed in a one-year, double-blind, multicenter study comparing FOSAMAX 70 mg once weekly and FOSAMAX 10 mg daily. The overall safety and tolerability profiles of once weekly FOSAMAX 70 mg and FOSAMAX 10 mg daily were similar. The adverse reactions considered by the investigators as possibly, probably, or definitely drug related in greater than or equal to 1% of patients in either treatment group are presented in Table 2.

Table 2: Osteoporosis Treatment Studies in Postmenopausal Women Adverse Reactions Considered Possibly, Probably, or Definitely Drug Related by the Investigators and Reported in Greater Than or Equal to 1% of Patients

Prevention Of Osteoporosis In Postmenopausal Women

The safety of FOSAMAX 5 mg/day in postmenopausal women 40-60 years of age has been evaluated in three double-blind, placebo-controlled studies involving over 1,400 patients randomized to receive FOSAMAX for either two or three years. In these studies the overall safety profiles of FOSAMAX 5 mg/day and placebo were similar. Discontinuation of therapy due to any clinical adverse event occurred in 7.5% of 642 patients treated with FOSAMAX 5 mg/day and 5.7% of 648 patients treated with placebo.

The safety of FOSAMAX 35 mg once weekly compared to FOSAMAX 5 mg daily was evaluated in a one-year, double-blind, multicenter study of 723 patients. The overall safety and tolerability profiles of once weekly FOSAMAX 35 mg and FOSAMAX 5 mg daily were similar.

The adverse reactions from these studies considered by the investigators as possibly, probably, or definitely drug related in greater than or equal to 1% of patients treated with either once weekly FOSAMAX 35 mg, FOSAMAX 5 mg/day or placebo are presented in Table 3.

Table 3: Osteoporosis Prevention Studies in Postmenopausal Women Adverse Reactions Considered Possibly, Probably, or Definitely Drug Related by the Investigators and Reported in Greater Than or Equal to 1% of Patients

In two studies (of one and two years' duration) of postmenopausal osteoporotic women (total: n=853), the safety and tolerability profile of combined treatment with FOSAMAX 10 mg once daily and estrogen ± progestin (n=354) was consistent with those of the individual treatments.

Osteoporosis In Men

In two placebo-controlled, double-blind, multicenter studies in men (a two-year study of FOSAMAX 10 mg/day and a one-year study of once weekly FOSAMAX 70 mg) the rates of discontinuation of therapy due to any clinical adverse event were 2.7% for FOSAMAX 10 mg/day vs. 10.5% for placebo, and 6.4% for once weekly FOSAMAX 70 mg vs. 8.6% for placebo. The adverse reactions considered by the investigators as possibly, probably, or definitely drug related in greater than or equal to 2% of patients treated with either FOSAMAX or placebo are presented in Table 4.

Table 4: Osteoporosis Studies in Men Adverse Reactions Considered Possibly, Probably, or Definitely Drug Related by the Investigators and Reported in Greater Than or Equal to 2% of Patients

Glucocorticoid-Induced Osteoporosis

In two, one-year, placebo-controlled, double-blind, multicenter studies in patients receiving glucocorticoid treatment, the overall safety and tolerability profiles of FOSAMAX 5 and 10 mg/day were generally similar to that of placebo. The adverse reactions considered by the investigators as possibly, probably, or definitely drug related in greater than or equal to 1% of patients treated with either FOSAMAX 5 or 10 mg/day or placebo are presented in Table 5.

Table 5: One-Year Studies in Glucocorticoid-Treated Patients Adverse Reactions Considered Possibly, Probably, or Definitely Drug Related by the Investigators and Reported in Greater Than or Equal to 1% of Patients

The overall safety and tolerability profile in the glucocorticoid-induced osteoporosis population that continued therapy for the second year of the studies (FOSAMAX: n=147) was consistent with that observed in the first year.

Paget's Disease Of Bone

In clinical studies (osteoporosis and Paget's disease), adverse events reported in 175 patients taking FOSAMAX 40 mg/day for 3-12 months were similar to those in postmenopausal women treated with FOSAMAX 10 mg/day. However, there was an apparent increased incidence of upper gastrointestinal adverse reactions in patients taking FOSAMAX 40 mg/day (17.7% FOSAMAX vs. 10.2% placebo). One case of esophagitis and two cases of gastritis resulted in discontinuation of treatment.

Additionally, musculoskeletal (bone, muscle or joint) pain, which has been described in patients with Paget's disease treated with other bisphosphonates, was considered by the investigators as possibly, probably, or definitely drug related in approximately 6% of patients treated with FOSAMAX 40 mg/day versus approximately 1% of patients treated with placebo, but rarely resulted in discontinuation of therapy. Discontinuation of therapy due to any clinical adverse events occurred in 6.4% of patients with Paget's disease treated with FOSAMAX 40 mg/day and 2.4% of patients treated with placebo.

Post-Marketing Experience

The following adverse reactions have been identified during post-approval use of FOSAMAX. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Body as a Whole: hypersensitivity reactions including urticaria and angioedema. Transient symptoms of myalgia, malaise, asthenia and fever have been reported with FOSAMAX, typically in association with initiation of treatment. Symptomatic hypocalcemia has occurred, generally in association with predisposing conditions. Peripheral edema.

Gastrointestinal: esophagitis, esophageal erosions, esophageal ulcers, esophageal stricture or perforation, and oropharyngeal ulceration. Gastric or duodenal ulcers, some severe and with complications, have also been reported [see DOSAGE AND ADMINISTRATION; WARNINGS AND PRECAUTIONS].

Localized osteonecrosis of the jaw, generally associated with tooth extraction and/or local infection with delayed healing, has been reported [see WARNINGS AND PRECAUTIONS].

Musculoskeletal: bone, joint, and/or muscle pain, occasionally severe, and incapacitating [see WARNINGS AND PRECAUTIONS]; joint swelling; low-energy femoral shaft and subtrochanteric fractures [see WARNINGS AND PRECAUTIONS].

Nervous System: dizziness and vertigo.

Pulmonary: acute asthma exacerbations.

Skin: rash (occasionally with photosensitivity), pruritus, alopecia, severe skin reactions, including Stevens-Johnson syndrome and toxic epidermal necrolysis.

Special Senses: uveitis, scleritis or episcleritis. Cholesteatoma of the external auditory canal (focal osteonecrosis).

Read the entire FDA prescribing information for Fosamax (Alendronate Sodium)

• Menopause
• Paget's Disease