Hovid Alendronate

Indications

• Osteoporosis in postmenopausal women
• Osteoporosis in men
• Paget's disease of bone
• Prevention of osteoporosis in patients receiving glucocorticoids

Dosage

Children: Refer to the BNF for Children for specific dosing information, as alendronic acid is not commonly used in pediatric populations.

Adults: Refer to the BNF for specific dosing information as it varies based on the condition treated.

Mechanism of action

Alendronic acid acts by inhibiting the enzyme farnesyl pyrophosphate synthase in the mevalonate pathway. This inhibition decreases the activity of osteoclasts, the cells responsible for bone resorption, leading to a net increase in bone density and strength.

Pharmacodynamics

The pharmacodynamic effects of alendronic acid include increased bone density and reduced incidence of vertebral and hip fractures. The drug preferentially accumulates in areas of high bone turnover, exerting its effects primarily on cortical and trabecular bone.

Pharmacokinetics

Alendronic acid is poorly absorbed from the gastrointestinal tract, with bioavailability estimated at 0.5% to 1%. After oral administration, peak plasma concentrations occur within 1 to 3 hours. The drug has a long half-life, with a terminal elimination half-life of approximately 10 years due to its strong binding to bone. It is primarily excreted unchanged in urine.

Contra-indications

• Hypersensitivity to alendronic acid or any excipients
• Abnormalities of the esophagus which delay esophageal emptying
• Inability to stand or sit upright for at least 30 minutes
• Hypocalcemia
• Severe renal impairment (creatinine clearance less than 35 mL/min)

Adverse effects

• Gastrointestinal disturbances (nausea, abdominal pain, dyspepsia)
• Esophageal irritation or ulceration
• Osteonecrosis of the jaw
• Atypical femoral fractures
• Musculoskeletal pain
• Hypocalcemia
• Skin rash or reactions
• Flu-like symptoms
• Renal impairment

Interactions

• Calcium supplements, antacids, or other medications containing divalent or trivalent cations may interfere with absorption
• NSAIDs may increase the risk of gastrointestinal adverse effects
• Other medications that affect renal function may enhance the risk of renal adverse effects

Precautions

• Use with caution in patients with a history of gastrointestinal disease
• Monitor renal function periodically during treatment
• Ensure adequate intake of calcium and vitamin D
• Advise patients about the signs and symptoms of osteonecrosis
• Caution in patients with a history of hypocalcemia

Pregnancy

Alendronic acid is not recommended during pregnancy due to potential risks to the fetus.

Breast-feeding

It is not known if alendronic acid is excreted in human breast milk. Caution is advised.

Storage

Store at room temperature, away from moisture and heat. Keep out of reach of children.

Formulations

• Tablets (e.g., 5 mg, 10 mg, 35 mg, 70 mg)
• Oral solution