Bisphosphonate — Oral (Weekly) Pregnancy: Alendronate should not be used during pregnancy or during breast-feeding. There are no or limited data from use in pregnant women; animal studies have shown reproductive toxicity, with dystocia related to hypocalcaemia in rats. It is unknown whether alendronate or its metabolites are excreted in human milk and a risk to the newborn/infant cannot be excluded. Bisphosphonates are incorporated into the bone matrix and released over years, so there is a theoretical risk of foetal harm, predominantly skeletal, if a woman becomes pregnant after completing a course.

Alendronic Acid (Rheumatology — Osteoporosis)

Brand names: Fosamax, Binosto

Used in: Falls & Frailty

Alendronic acid is an oral nitrogen-containing bisphosphonate used in rheumatology to treat and prevent osteoporosis, including corticosteroid-induced bone loss. It is typically taken once weekly to reduce fracture risk.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 70 mg

Route: Oral

Frequency: One tablet per week

Fetched UK SPC: Alendronic Acid 70 mg Film-coated Tablets (eMC product 101969). Administration is critical to safety and absorption: the tablet must be taken on an empty stomach immediately on rising in the morning, with plain water only, at least 30 minutes before the first food, drink or other medication of the day. It should be swallowed whole on arising for the day with a whole glass of water (not less than 200 ml / 7 fl.oz); it should not be chewed, sucked or allowed to dissolve in the mouth because of the risk of oropharyngeal ulceration. Patients should not lie down until after the first meal of the day, which must be at least 30 minutes after taking the tablet, and should not lie down within 30 minutes of taking it. It should not be taken at bedtime or before arising for the day. Missed dose: take the tablet the following morning after realising it has been missed; do not take two tablets on the same day, and continue with one tablet a week on the originally scheduled day. Patients should be given a calcium and vitamin D supplement if the diet is inadequate. The optimal duration of bisphosphonate treatment for osteoporosis has not been established; the need for continued treatment should be re-evaluated periodically on an individual patient basis, particularly after 5 or more years of use. This SPC explicitly states that Alendronic Acid has not been investigated in the treatment of glucocorticoid-induced osteoporosis. No dose adjustment is necessary for elderly patients or for hepatic impairment. Paediatric (no per-kg dose is stated, so paedDose is null): the SPC states alendronate sodium is not recommended for use in children under the age of 18 years due to insufficient data on safety and efficacy in conditions associated with paediatric osteoporosis. Verify any under-18 use against a children's formulary. No openFDA/US label was fetched in this bundle and the bundle contains no §4.5 interactions section, so the interactions list below is limited to the absorption warning carried in §4.2.

Dose adjustments

Renal

No dose adjustment is necessary in patients with a creatinine clearance greater than 35 ml/min. Alendronate is not recommended for patients with impaired renal function if the creatinine clearance is less than 35 ml/min, as there is no experience of this.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Hypersensitivity to the active substance or to any of the excipients
Oesophageal abnormalities and other factors that delay oesophageal emptying, such as stricture or achalasia
Inability to stand or sit upright for at least 30 minutes
Hypocalcaemia

Side effects

Abdominal pain, dyspepsia, acid regurgitation, abdominal distension, constipation, diarrhoea and flatulence (common)
Oesophageal ulcers and dysphagia (common); oesophagitis, oesophageal erosions, nausea, vomiting and gastritis (uncommon); oesophageal stricture and oropharyngeal ulceration (rare)
Musculoskeletal pain (bone, muscle or joints)
Headache, dizziness and vertigo (common)
Alopecia and pruritus (common)
Symptomatic hypocalcaemia (rare); hypersensitivity reactions including urticaria and angioedema (rare); eye inflammation — uveitis, scleritis, episcleritis (uncommon)

Interactions

Other drinks (including mineral water), food and some medicines are likely to reduce the absorption of alendronate — the tablet must be taken at least 30 minutes before the first food, drink or other medication of the day (§4.2, cross-referring to §4.5, which was not retrieved in this bundle)

Clinical monograph

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.

Reference: FIT Trial (NEJM 1996); MHRA DSU 2008 (oesophageal reactions); MHRA 2010 (oesophageal cancer); NICE TA204; NOGG Osteoporosis Guidelines; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways