Bisphosphonate

Alendronic Acid (Alendronate)

Brand names: Fosamax, Binosto (effervescent)

Alendronic acid is an oral bisphosphonate used to treat and prevent osteoporosis and reduce fracture risk.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

Clinical monograph

How it works

It binds to bone and inhibits osteoclast-mediated bone resorption, increasing bone mineral density.

Prescribing in practice

Strict administration is essential — take on waking with a full glass of plain water, then stay upright and fasting for at least 30 minutes, to aid absorption and avoid oesophageal injury.
Avoid in oesophageal abnormalities or where the patient cannot sit or stand upright, and ensure adequate calcium and vitamin D.
Rare osteonecrosis of the jaw and atypical femoral fractures occur with long-term use; consider a dental check before starting and review the duration of therapy.

Monitoring

Review fracture risk and the need to continue (drug-holiday consideration), calcium/vitamin D status and dental health.

Counselling the patient

Take it exactly as instructed: empty stomach, plenty of water, stay upright, and wait before food or other tablets.
Report new thigh or groin pain, or dental problems.

Evidence & guidelines

First-line for osteoporotic fracture prevention (NICE TA464 / NOGG), with calcium and vitamin D repletion.

Reference: NICE CG146 (Osteoporosis); NICE TA160; FRAX tool; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

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