Alendronic Acid (Fosamax)

1. Health Canada Product Monograph — Alendronic Acid

• Alendronic acid is used to treat osteoporosis in postmenopausal women, increasing bone mass and reducing the risk of hip and spine fractures.
• Alendronic acid is used to treat osteoporosis in men.
• Alendronic acid is used to prevent osteoporosis in postmenopausal women who are at risk of bone loss.
• Alendronic acid is used to treat and prevent glucocorticoid-induced osteoporosis in men and women taking long-term corticosteroids.
• The optimal duration of treatment has not been established, and the need for continued therapy should be reassessed periodically.

• Alendronic acid should not be used during pregnancy; it has not been studied in pregnant women, and safety for the developing fetus has not been established.

• Alendronic acid should not be used while breastfeeding, as it is not known whether it passes into human breast milk and a risk to the nursing infant cannot be excluded.

• Alendronic acid does not require dosage adjustment based on age alone in older adults, and clinical studies found no age-related difference in effectiveness or safety.

• Alendronic acid is not approved for use in children, as safety and effectiveness have not been established in this age group.

• For treatment of osteoporosis in postmenopausal women and men, the usual dose of alendronic acid is 70 mg once weekly or 10 mg once daily.
• For prevention of osteoporosis in postmenopausal women, the usual dose is 5 mg once daily.
• For treatment and prevention of glucocorticoid-induced osteoporosis, the usual dose is 5 mg once daily, increased to 10 mg once daily in postmenopausal women not taking estrogen.
• No dosage adjustment is needed for mild-to-moderate kidney impairment, but alendronic acid should not be used if kidney function is more severely reduced.
• If a weekly dose is missed, take one dose the next morning after remembering, then return to the original weekly schedule; never take two doses on the same day.

If overdose is suspected, seek emergency medical attention immediately or contact your regional Poison Control Centre without delay.

• Overdose of alendronic acid can cause low blood calcium, low blood phosphate, and upper digestive symptoms such as upset stomach, heartburn, esophagitis, gastritis, or ulcers.
• Milk or an antacid should be given to bind the drug in the stomach.
• Vomiting should not be induced, and the person should remain fully upright to reduce the risk of esophageal irritation.
• Dialysis does not remove alendronic acid from the body and would not be expected to help.

• Stomach pain may occur.
• Indigestion may occur.
• Constipation may occur.
• Diarrhea may occur.
• Gas (flatulence) may occur.
• Acid regurgitation may occur.
• Nausea may occur.
• Bone, muscle, or joint pain may occur.
• Headache may occur.
• A change in sense of taste may occur.

Serious side effects require immediate discussion with the prescriber or emergency care.

• Alendronic acid can cause esophagitis, esophageal ulcers, or esophageal erosions, which may rarely progress to stricture or perforation of the esophagus.
• Ulcers of the stomach or first part of the small intestine (duodenum) have been reported, occasionally severe.
• Osteonecrosis of the jaw, usually linked to tooth extraction or dental infection, can occur, particularly in patients with cancer, poor oral hygiene, or other risk factors.
• Unusual thigh or hip fractures (atypical femur fractures) can occur with long-term use, sometimes preceded by weeks or months of aching pain in the groin or thigh.
• Severe or occasionally disabling bone, joint, or muscle pain has been reported.
• Osteonecrosis of the external auditory canal (ear canal bone damage) has been reported.
• Low blood calcium (hypocalcemia) can occur, particularly if calcium and vitamin D levels are not corrected before starting treatment.
• Eye inflammation, including uveitis, scleritis, or episcleritis, has been reported.
• Severe allergic reactions, including hives and swelling of the face or throat, can occur.
• Severe skin reactions, including Stevens-Johnson syndrome and toxic epidermal necrolysis, have been reported rarely.
• Seek urgent medical attention for difficulty or pain swallowing, chest pain, severe heartburn, new hip or thigh pain, or signs of a severe allergic or skin reaction.

• Use with caution in patients with swallowing difficulties, esophageal disease (including Barrett's esophagus), or active stomach or duodenal ulcers.
• Use with caution in patients who cannot follow the dosing instructions, including standing or sitting upright for at least 30 minutes after the dose.
• Correct low calcium and vitamin D levels before starting treatment, and monitor calcium levels during therapy.
• Use with caution in patients with risk factors for osteonecrosis of the jaw, such as cancer, chemotherapy, corticosteroid use, poor dental hygiene, or planned dental surgery; a dental check-up before starting is recommended in these patients.
• Use with caution in patients with risk factors for atypical femur fracture, such as long-term use, and evaluate the opposite leg if a stress fracture is suspected in one thigh.
• Use with caution in patients with mild-to-moderate kidney impairment.

• Contraindicated in patients with hypersensitivity to alendronic acid or any ingredient in the product.
• Contraindicated in patients with abnormalities of the esophagus that delay emptying, such as stricture or achalasia.
• Contraindicated in patients who cannot stand or sit upright for at least 30 minutes.
• Contraindicated in patients with low blood calcium (hypocalcemia) that has not been corrected.
• Contraindicated in patients with severe kidney impairment (creatinine clearance below 35 mL/min).

• Calcium supplements, antacids, and other oral medications interfere with the absorption of alendronic acid; other oral medications should be taken at least 30 minutes after alendronic acid.
• Ranitidine has been shown to double the absorption of alendronic acid; the clinical significance of this is unknown.
• Combining alendronic acid with hormone replacement therapy (estrogen with or without progestin) may produce greater increases in bone mass than either treatment alone.
• Taking nonsteroidal anti-inflammatory drugs (NSAIDs) or acetylsalicylic acid together with alendronic acid may increase the risk of stomach irritation.
• Herbal products can interfere with the absorption of alendronic acid and should be taken at least 30 minutes after the dose.

• Alendronic acid must be taken on an empty stomach; food, beverages other than plain water, and other medications markedly reduce its absorption, so it must be taken at least 30 minutes before the first food, drink, or medication of the day.
• Mineral water, coffee, tea, and juice should also be avoided when taking the dose, as they reduce absorption in the same way as food.

• Alendronic acid should be taken first thing in the morning, upon rising for the day, and never at bedtime or before getting up.
• The tablet should be swallowed with a full glass (200-250 mL) of plain water only, and the patient should remain fully upright (sitting, standing, or walking) for at least 30 minutes and until after the first food of the day.

• Store alendronic acid tablets at room temperature (15°C to 30°C) and keep out of the reach and sight of children.

• Alendronic acid helps strengthen bone and reduce fracture risk, but it only works if taken exactly as directed on an empty stomach with plain water, followed by staying upright for at least 30 minutes.
• Report any difficulty or pain swallowing, chest pain, new or worsening heartburn, or new hip or thigh pain to a healthcare professional right away.
• Continue taking any prescribed calcium and vitamin D supplements while on alendronic acid unless told otherwise.