1. Introduction
Alendronic acid, commonly marketed under brand names such as Fosamax and Binosto, is a bisphosphonate used primarily for the prevention and treatment of osteoporosis. It works by inhibiting osteoclast-mediated bone resorption, thereby increasing bone mineral density.
2. Indications
- Approved Indications:
- Treatment and prevention of osteoporosis in postmenopausal women.
- Treatment of osteoporosis in men.
- Glucocorticoid-induced osteoporosis in patients receiving long-term steroid therapy.
- Treatment of Paget’s disease of bone.
- Off-Label Uses:
- Reduction of fracture risk in high-risk patients.
3. Dosage
- Osteoporosis (Postmenopausal Women and Men):
- 10 mg once daily OR 70 mg once weekly.
- Glucocorticoid-Induced Osteoporosis:
- 5 mg once daily OR 10 mg once daily (for postmenopausal women not on hormone replacement therapy).
- Paget’s Disease:
- 40 mg once daily for 6 months.
4. Administration
- Take orally with a full glass of water (at least 200 mL).
- Administer at least 30 minutes before the first food, drink, or medication of the day.
- Remain upright (sitting or standing) for at least 30 minutes after administration.
- Avoid lying down immediately to reduce the risk of oesophageal irritation.
5. Forms Available
- Tablets: 5 mg, 10 mg, 35 mg, 40 mg, 70 mg.
- Effervescent tablets (Binosto): 70 mg.
6. Side Effects
6.1. Common Side Effects
- Abdominal pain.
- Dyspepsia.
- Musculoskeletal pain (bone, joint, or muscle).
- Nausea.
6.2. Less Common Side Effects
- Oesophageal ulcer or irritation.
- Constipation or diarrhoea.
- Headache.
6.3. Rare but Serious Side Effects
- Osteonecrosis of the jaw (ONJ).
- Atypical femoral fractures.
- Severe oesophageal reactions (stricture, perforation).
- Hypocalcaemia.
7. Warnings
- Contraindicated in patients with oesophageal abnormalities that delay oesophageal emptying.
- Avoid use in patients who cannot remain upright for 30 minutes.
- Risk of severe musculoskeletal pain and osteonecrosis of the jaw.
8. Precautions
- Use with caution in patients with active upper gastrointestinal disorders.
- Correct hypocalcaemia and vitamin D deficiency before starting therapy.
- Monitor dental health in patients at risk for osteonecrosis.
9. Interactions
- Calcium supplements, antacids, or other multivalent cations may interfere with absorption.
- Avoid simultaneous administration with NSAIDs to reduce gastrointestinal irritation.
- Alcohol use may exacerbate gastrointestinal side effects.
10. Monitoring Parameters
- Bone mineral density (BMD) every 1–2 years.
- Serum calcium and vitamin D levels.
- Renal function (baseline and periodic).
11. Use in Children
- Not recommended; safety and efficacy have not been established in paediatric populations.
12. Use in Pregnancy
- Category C: Risk cannot be ruled out.
- Use only if the potential benefit justifies the risk to the foetus.
- Animal studies show adverse skeletal effects on the developing foetus.
13. Use in Elderly
- No specific dose adjustment needed.
- Increased susceptibility to gastrointestinal side effects and renal impairment requires careful monitoring.
14. Use in Kidney Disease
- Avoid use in patients with creatinine clearance <35 mL/min.
- No dosage adjustment necessary for mild-to-moderate renal impairment.
15. Use in Liver Disease
- No dosage adjustment required; alendronic acid is not metabolised by the liver.
16. Patient Counselling Points
- Emphasise taking the tablet with water on an empty stomach.
- Highlight the need to remain upright for at least 30 minutes after ingestion.
- Inform about the importance of regular dental check-ups.
- Advise reporting any signs of jaw pain, severe bone pain, or difficulty swallowing immediately.
17. Table of Brand Names, Manufacturers, and Prices
Brand Name | Manufacturer | Price (USD) |
---|---|---|
Fosamax | Merck & Co. | $30 (70 mg x 4) |
Binosto | Mission Pharmacal | $45 (70 mg x 4) |
Generic Options | Various | $15 (70 mg x 4) |
18. FAQs (15 Questions)
- What is alendronic acid used for?
Alendronic acid is used for treating osteoporosis, Paget’s disease, and preventing fractures in at-risk patients. - How does alendronic acid work?
It inhibits bone resorption by osteoclasts, increasing bone density. - Can I take alendronic acid with food?
No, it should be taken on an empty stomach with water only. - What are the common side effects of alendronic acid?
Abdominal pain, nausea, and musculoskeletal pain are common. - Are there any serious side effects?
Yes, osteonecrosis of the jaw and atypical femoral fractures are rare but serious. - Can pregnant women take alendronic acid?
It is not recommended due to potential risks to the foetus. - Can children use alendronic acid?
No, its use is not established in children. - How should alendronic acid be stored?
Store at room temperature, away from moisture and heat. - What happens if I miss a dose?
Take the dose the next morning; do not take two tablets in one day. - Can I drink alcohol while taking alendronic acid?
It is best to avoid alcohol to minimise gastrointestinal irritation. - What are the signs of an overdose?
Symptoms include hypocalcaemia, hypophosphataemia, and upper GI side effects. - Is alendronic acid safe for elderly patients?
Yes, but with careful monitoring for side effects. - Can alendronic acid interact with other medications?
Yes, avoid taking it with calcium, antacids, or NSAIDs at the same time. - How long does it take for alendronic acid to work?
Significant effects on bone density may take 6–12 months. - Do I need regular tests while taking alendronic acid?
Yes, regular bone density, calcium, and kidney function tests are advised.