[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Laxatives](https://durgical.com/en/pharmacology/classes/laxatives/) › Linaclotide

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# Linaclotide

A small peptide that acts on the gut lining to release chloride and water into the bowel. Used for constipation-predominant irritable bowel syndrome.

Updated 2026-11-01

- Class: [Laxatives](https://durgical.com/en/pharmacology/classes/laxatives/)
- Receptor: Guanylate cyclase C (GC-C) on the luminal surface of intestinal cells
- ATC code: A06AX04

## Mechanism of action

Linaclotide is a short peptide that is barely absorbed. It binds guanylate cyclase C on the luminal surface of the intestinal lining and raises cyclic GMP inside and outside the cells. Cyclic GMP activates the CFTR channel, which secretes chloride-rich fluid into the lumen; water follows, stools soften and transit speeds up.

- Binds guanylate cyclase C on the gut lining
- Cyclic GMP rises inside and outside the cells
- CFTR opens and secretes chloride; water follows
- Softer stool and faster transit

## Pharmacokinetics

**Absorption**
Negligible absorption; it acts locally in the gut

**Onset and duration**
The full benefit may take a week or longer

## Indications

- Irritable bowel syndrome with constipation in adults [Irritable bowel syndrome →](https://durgical.com/en/conditions/irritable-bowel-syndrome/)
- Chronic idiopathic constipation in adults [Constipation and faecal impaction →](https://durgical.com/en/conditions/constipation-and-faecal-impaction/)
- Functional constipation in children 6 years and older [Functional constipation in children →](https://durgical.com/en/conditions/functional-constipation-in-children/)

## Adverse effects

### Common

- Diarrhoea (the most common)
- Abdominal pain
- Bloating and flatulence
- Headache

### Serious (rare, important)

- Severe diarrhoea with dehydration
- Severe abdominal pain or bloody or black stools
- Allergic reactions

## Contraindications

- Children under 2 years
- Known or suspected mechanical bowel obstruction

## Key interactions

**Other systemic medicines**
It is barely absorbed, so few drug interactions are expected

## What is monitored

- Stool frequency and diarrhoea
- Signs of dehydration (thirst, dry mouth, sunken eyes, fast heart rate)
- Abdominal pain

## Administration and safety

- Taken once a day on an empty stomach, before a meal.
- Capsules are swallowed whole; if swallowing is hard, the contents can be sprinkled on applesauce or mixed in water and taken at once, or given through a feeding tube.

## Nursing care

- Rule out bowel obstruction and check the patient's age before starting.
- Teach that diarrhoea is the most common effect and that severe diarrhoea is reported at once.
- Watch for dehydration in older adults and children.
- Explain that symptoms may return about a week after stopping.

## Pregnancy and breastfeeding

It is barely absorbed, so fetal exposure is expected to be very low; its use in pregnancy is decided case by case.

## Memory aid

LINAclotide = «LINe up the chloride»: GC-C, cGMP, CFTR, then water.

## Test yourself

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

## Which receptor does linaclotide activate?

Guanylate cyclase C on the luminal surface of the intestinal lining.

## Which channel finally secretes chloride after linaclotide?

CFTR, activated by the rise in cyclic GMP.

## What is the most common adverse effect of linaclotide?

Diarrhoea.

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## Related drugs

- [Lubiprostone](https://durgical.com/en/pharmacology/lubiprostone/)

## Related conditions

- [Irritable bowel syndrome](https://durgical.com/en/conditions/irritable-bowel-syndrome/)
- [Constipation and faecal impaction](https://durgical.com/en/conditions/constipation-and-faecal-impaction/)
- [Functional constipation in children](https://durgical.com/en/conditions/functional-constipation-in-children/)

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

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

Sources: [Linaclotide: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a613007.html) (MedlinePlus (U.S. National Library of Medicine), 2026); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=A06AX) (WHO Collaborating Centre for Drug Statistics Methodology, 2026); Farmacología básica y clínica (Katzung), 16.ª ed., cap. 62 (McGraw Hill, 2025).

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