[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Bisphosphonates](https://durgical.com/en/pharmacology/classes/bisphosphonates/) › Risedronic acid (risedronate)

# Risedronic acid (risedronate)

## Bisphosphonates?

Bisphosphonates

## Pregnancy: avoid?

Not used in pregnancy; stopped if pregnancy is recognised, and stored drug in bone is a theoretical risk for the fetal skeleton.

An oral bisphosphonate for osteoporosis and Paget disease, taken under the same strict rules as alendronate to protect the oesophagus.

Updated Nov 1, 2026

Also called: Risedronate sodium

## Quick facts

**Group**
[Bisphosphonates](https://durgical.com/en/pharmacology/classes/bisphosphonates/)

**Target**
Farnesyl pyrophosphate synthase (FPPS), an enzyme of the mevalonate pathway in osteoclasts

**Used for**
Treatment and prevention · Osteoporosis in men

**Key effects**
Nausea · Diarrhoea or constipation · Headache

**Monitor**
Calcium and vitamin D before starting · Dental health

**ATC**
M05BA07

No doses: the clinician sets them by the current guideline.

On this page

- The basics Mechanism of action
- Indications
- Adverse effects
- Pharmacokinetics
- Memory aid

- Clinical What the labels mean

- Safety Contraindications
- Key interactions
- What is monitored
- Administration and safety
- Pregnancy and breastfeeding
- Nursing care

- Study Test yourself

- Connections Connections

## Mechanism of action

✂**Farnesyl pyrophosphate synthase (FPPS), an enzyme of the mevalonate pathway in osteoclasts**Risedronic acid (risedronate)

ⓘ The figure shows risedronate itself in the active site of human farnesyl pyrophosphate synthase, with magnesium ions.

**Target in 3D:** Farnesyl pyrophosphate synthase (FPPS), an enzyme of the mevalonate pathway in osteoclasts. PDB structure 1YV5 (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/1YV5) · Drag to rotate · pinch to zoom

Risedronate is a pyridinyl (nitrogen-containing) bisphosphonate. It binds hydroxyapatite and, once taken up by osteoclasts, inhibits farnesyl pyrophosphate synthase. Osteoclast activity and bone turnover fall, bone density rises and fractures become less frequent.

- Risedronate binds bone mineral at resorption sites
- Osteoclasts take it up as they resorb bone
- It blocks farnesyl pyrophosphate synthase
- Bone turnover falls and density rises

## Indications

- Treatment and prevention of postmenopausal osteoporosis [Osteoporosis →](https://durgical.com/en/conditions/osteoporosis/)
- Osteoporosis in men and glucocorticoid-induced osteoporosis
- Paget disease of bone [Paget disease of bone →](https://durgical.com/en/conditions/paget-disease-of-bone/)

## Adverse effects

### Common

- Nausea, abdominal pain, dyspepsia
- Diarrhoea or constipation
- Back and joint pain
- Headache

### Serious (rare, important)

- Oesophagitis and oesophageal ulcers
- Osteonecrosis of the jaw
- Atypical femoral fractures
- Severe bone, joint or muscle pain
- Hypocalcaemia

## Contraindications

- Oesophageal abnormalities that delay emptying, such as stricture or achalasia
- Inability to stand or sit upright for at least 30 minutes
- Hypocalcaemia
- Hypersensitivity to risedronate
- Not recommended with severe kidney impairment

## Key interactions

**Calcium, antacids, iron and other divalent cations**
Lower risedronate absorption; they are taken at a different time

**Food and any drink other than plain water**
Much lower absorption; the immediate-release tablet is taken before food or drink

## What is monitored

- Calcium and vitamin D before starting
- Kidney function
- Bone density and fracture risk over time
- Swallowing symptoms and heartburn
- Dental health; thigh or groin pain

## Administration and safety

- Immediate-release tablets: first thing in the morning, before any food or drink, with plain water
- The delayed-release form is the exception: it is taken right after breakfast
- Swallowed whole, not chewed or sucked; the person stays upright for at least 30 minutes
- Calcium, antacids and other oral medicines are separated from the dose

## Pregnancy and breastfeeding

Not used in pregnancy; stopped if pregnancy is recognised, and stored drug in bone is a theoretical risk for the fetal skeleton.

## Nursing care

- Confirm which form is ordered (immediate or delayed release), because the timing with food is opposite
- Check that the person can stay upright
- Teach to report pain on swallowing, new heartburn or chest pain
- Review calcium and vitamin D intake and dental care
- Report thigh or groin pain

## Pharmacokinetics

**Absorption**
Very low oral absorption, reduced further by food

**Metabolism**
Not metabolised; it neither induces nor inhibits CYP enzymes

**Elimination**
By the kidney; clearance falls with kidney impairment

## Memory aid

RISEdronate: RISE in the morning, stay RISEn (upright), and only then eat.

## Test yourself

Think of the answer, then tap the question to see it.

## How does the timing of delayed-release risedronate differ from the usual tablets?

The usual tablets are taken before any food or drink in the morning; the delayed-release form is taken right after breakfast.

## Why is risedronate avoided in severe kidney impairment?

It is cleared by the kidney, so the drug accumulates; the label does not recommend it below a low creatinine clearance.

## Which bisphosphonate group does risedronate belong to, and what does it inhibit?

It is a pyridinyl, nitrogen-containing bisphosphonate that inhibits farnesyl pyrophosphate synthase in osteoclasts.

[Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/risedronic-acid/)

[More Pharmacology questions →](https://durgical.com/en/practice/?f=pharmacology)

## What the labels mean

**Pregnancy: avoid**
Not used in pregnancy; stopped if pregnancy is recognised, and stored drug in bone is a theoretical risk for the fetal skeleton.

## Connections

## Related drugs 3

- [Alendronic acid (alendronate)](https://durgical.com/en/pharmacology/alendronic-acid/)
- [Zoledronic acid](https://durgical.com/en/pharmacology/zoledronic-acid/)
- [Denosumab](https://durgical.com/en/pharmacology/denosumab/)

## Related conditions 2

- [Osteoporosis](https://durgical.com/en/conditions/osteoporosis/)
- [Paget disease of bone](https://durgical.com/en/conditions/paget-disease-of-bone/)

[← Back to the class: Bisphosphonates](https://durgical.com/en/pharmacology/classes/bisphosphonates/)

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: [Risedronate: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a601247.html) (MedlinePlus (U.S. National Library of Medicine), 2026); [DailyMed - RISEDRONATE SODIUM tablet, film coated](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=dddcd321-4d2e-4643-bf3c-7b752b33ba39) (DailyMed (U.S. National Library of Medicine), 2026); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=M05BA07) (WHO Collaborating Centre for Drug Statistics Methodology, 2026).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/pharmacology/risedronic-acid/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/risedronic-acid/