Alendronate: Uses, Indications, Dosages, Precautions, Contraindications, Side Effects & Interactions

Alendronate

(a-len-dro-nate)
Classification 
Pharmacotherapeutic: Bisphosphonate
Clinical: Bone resorption inhibitor, calcium regulator

Apo-Alendronate

CO Alendronate

Fosamax

Fosamax plus D

CATEGORY AND SCHEDULE

Pregnancy Risk Category: C

Do not confuse:

Fosamax/Flomax

General Information

Alendronate belongs to the Bisphosphonate group of bone resorption inhibitor and calcium regulator group of drugs. Fosamax: treatment of osteoporosis in men. Treatment of glucocorticoid-induced osteoporosis in men and women with low bone mineral density who receive at least 7.5 mg of predniSONA (or equivalent). Treatment and prevention of osteoporosis in men and postmenopausal women. Treatment of Paget's disease of bone in  patients who are symptomatic, at risk of future complications or with alkaline phosphatase equal to or greater than 2 times the ULN. Binosto: Treatment of osteoporosis in men and postmenopausal women. Fosamax Plus D: alendronate / cholecalciferol (vitamin D analogue): 70 mg / 2800 international units, 70 mg / 5600 international units

Alendronate can cause severe reactions, such as: overdose causes hypocalcaemia, hypophosphataemia and significant gastrointestinal disturbances, esophageal irritation occurs if alendronate is not given with 6-8 oz of plain water or if the patient lies down within 30 minutes from the administration of the drug. and occasionally pain in the debilitating bones, joints, or muscles. Rare cases of atypical femur fractures. Osteonecrosis of the jaw. More data needed; possible increased risk of esophageal cancer

Action

A bisphosphonate that inhibits normal and abnormal bone resorption, without retarding mineralization

Therapeutic Effect

Leads to increased bone mineral density. Paget’s disease: Decreases bone formation, but the bone has a more normal architecture

Availability (Rx)

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

Oral Solution: 70 mg/75 mL

Uses

Treatment and prevention of osteoporosis in postmenopausal women, treatment of osteoporosis in men, Paget’s disease, treatment of corticosteroid-induced osteoporosis in postmenopausal women not receiving estrogen, or in men who are continuing corticosteroid treatment with low bone mass

Precautions

Pregnancy C, breastfeeding, children, CCr ,35 ml/min, esophageal disease, increased esophageal cancer risk, ulcers, gastritis, poor dental health

Make sure to tell your doctor if:

• You have long-term liver or kidney problems

• You have diabetes

• You have GI problems

• You are taking other medicines

Indications and Dosages

‣ To treat postmenopausal osteoporosis (women)

PO

• Adults, Elderly: 10 mg once a day in the morning, or 70 mg once weekly

‣ To Treat Osteoporosis in men

PO

• Adults, Elderly: 10 mg once a day in the morning, or 70 mg once weekly

‣ To prevent postmenopausal osteoporosis

PO

• Adults, Elderly: 5 mg once a day in the morning or 35 mg once weekly

‣ To Treat Glucocorticoid-induced osteoporosis

PO

• Adults, Elderly. 5 mg once a day in the morning

• Postmenopausal women not receiving estrogen. 10 mg once a day in the morning

‣ To Treat Paget’s Disease

PO

• Adults, Elderly. 40 mg once a day in the morning for 6 mo; then wait 6 mo before considering retreatment

Pharmacokinetics

Poorly absorbed after oral administration; oral bioavailability < 1%. Protein binding: 78%. After oral administration, rapidly taken into bone, with uptake greatest at sites of active bone turnover. Excreted in urine. Terminal halflife: > 10 yr (reflects release from skeleton as bone is resorbed)

Implementation

PO route

• Give PO for 6 mo to be effective in Paget’s disease; take with 8 oz of water 30 min before 1st food, beverage, or medication of the day

• Patient to remain upright for 30 min after dose to prevent esophageal irritation

• Store in cool environment out of direct sunlight

Contraindications

Abnormalities of the esophagus that delay esophageal emptying, such as stricture or achalasia; hypocalcemia; inability to stand or sit upright for at least 30 min; renal impairment (CrCl < 35 mL/min); sensitivity to alendronate or phosphonates; patients with aspiration risk

Cautions: Renal impairment, dysphagia, esophageal disease, gastritis, ulcers, or duodenitis

Interactions

Individual drugs

• Calcium, antacids may decrease absorption 

• Aspirin, NSAIDs may increase risk of ulcers, upper GI adverse effects

Drug classifications

• Aminoglycosides, antacids, calcium supplements: decreased absorption H2 blockers, proton pump inhibitors (PPIs), gastric mucosal agents, NSAIDs, salicylates: adverse GI reactions

Drug/laboratory tests

• Reduces serum calcium, phosphate

• Significant decrease in serum alkaline phosphatase noted in pts with Paget’s disease

Drugs/food

• Concurrent beverages, orange juice, dietary supplements, food may interfere with absorption

• Caffeine may reduce efficacy

Herbal

• None significant

Side effects

• CNS: Asthenia, dizziness, headache, vertigo

• CV: Peripheral edema

• GI: Abdominal distention and pain, constipation, diarrhea, dysphagia, esophageal perforation or ulceration, esophagitis, flatulence, gastritis, gastroesophageal reflux disease, heartburn, indigestion, melena, nausea, vomiting

• MS: Arthralgia, bone pain, focal osteomalacia, joint swelling, muscle spasms, myalgia

• SKIN: Photosensitivity, pruritus, rash, Stevens-Johnson syndrome, toxic epidermal necrolysis

• Other: Hypocalcemia

 

Nursing considerations

Baseline assessment

• Obtain baseline serum calcium, phosphate, alkaline phosphatase. Hypocalcemia,

vitamin D deficiency must be corrected before beginning therapy

• Assess pt’s ability to remain upright for at least 30 minutes

Intervention/evaluation

• Monitor chemistries (esp. serum calcium, phosphorus, alkaline phosphatase

levels)

Equipment must be available for anaphylaxis

• Assess for serious reactions: angioedema, Stevens-Johnson syndrome, toxic

epidermal necrolysis, atrial fibrillation

• Assess dental status, regular dental exams should be done; dental extractions (cover with antiinfectives) prior to procedure

• Hormonal status if a woman, prior to treatment

• Assess for osteoporosis: bone density testing

• For Paget’s disease: increased skull size, bone pain, headache

• Monitor renal studies and electrolytes (calcium, potassium, magnesium, phosphorous) BUN/creatinine

• Assess for hypercalcemia: paresthesia, twitching, laryngospasm, Chvostek’s, Trousseau’s signs

• Monitor alkaline phosphatase; level of 2 ✖ upper limit of normal is indicated for Paget’s disease

Evaluation

Positive therapeutic result

• Increased bone mass, absence of fractures

Patient/family teaching

• Tell patient to expected benefits occur only when medication is taken with full glass (6–8 oz) of plain water, first thing in the morning and at least 30 min before first food, beverage, or medication of the day is taken. Any other beverage (mineral water, orange juice, coffee) significantly reduces absorption of medication

• Tell patient to do, not lie down for at least 30 min after taking medication (potentates delivery to the stomach, reducing risk of esophageal irritation)

• Tell patient to report new swallowing difficulties, pain when swallowing, chest pain, new/worsening heartburn

• Teach patient to take calcium, vit D if instructed by provider

• Teach patient to use weight-bearing exercise to increase bone density

• Teach patient to let provider know if pregnancy is planned or suspected or if nursing

• Advise to maintain good oral hygiene

• Inform patient to modify behavioral factors (e.g., cigarette smoking, alcohol consumption)