Alendronic Acid (Rheumatology — Osteoporosis)

How it works

It binds avidly to bone mineral and inhibits osteoclast-mediated bone resorption, increasing bone mineral density and reducing the risk of vertebral and other fragility fractures.

Prescribing in practice

• To prevent oesophageal irritation and ulceration it must be taken on an empty stomach with a full glass of water while sitting or standing upright, remaining upright and not eating for a period afterwards.
• It is contraindicated in significant oesophageal abnormalities, hypocalcaemia and inability to stay upright, and calcium or vitamin D deficiency should be corrected first.
• Rare osteonecrosis of the jaw and atypical femoral fractures warrant dental assessment beforehand and review of long-term need.

Monitoring

Monitor for upper gastrointestinal symptoms, ensure adequate calcium and vitamin D status, and review fracture risk and treatment duration periodically.

Counselling the patient

• Take it on rising with plain water, stay upright and do not eat, drink or take other medicines for the advised interval.
• Report difficulty or pain on swallowing, persistent thigh pain, or new dental problems.

Evidence & guidelines

Alendronic acid is supported by large randomised trials and NICE guidance showing reduced fracture risk, making it a first-line osteoporosis treatment.