Guanylate cyclase-C agonist Pregnancy: US label: linaclotide and its active metabolite are negligibly absorbed systemically after oral administration and maternal use is not expected to result in foetal exposure; available data on use in pregnant women are not sufficient to inform any drug-associated risk of major birth defects or miscarriage.

Linaclotide

Brand names: Constella

Linaclotide is a guanylate cyclase-C agonist used for the treatment of moderate to severe irritable bowel syndrome with constipation in adults.

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: Irritable bowel syndrome with constipation (IBS-C): 290 micrograms. Chronic idiopathic constipation (CIC): 145 micrograms (72 micrograms once daily may be used based on individual presentation or tolerability)

Route: Oral — swallow the capsule whole; do not crush or chew the capsule or its contents

Frequency: Once daily on an empty stomach, at least 30 minutes prior to a meal, at approximately the same time each day

US labelling (LINZESS) — no UK SPC was retrieved, so verify against the UK SPC. If a dose is missed, skip it and take the next dose at the regular time; do not take 2 doses at the same time. For patients unable to swallow the capsule whole, the capsule may be opened and the beads given in one teaspoonful of room-temperature applesauce, or in approximately 30 mL of room-temperature bottled water (swirl at least 20 seconds and swallow immediately), or via a nasogastric or gastrostomy tube with water — the drug dissolves off the beads, so it is not necessary to consume or flush through all the beads. Sprinkling on other soft foods or liquids has not been tested. Elderly: no separate dosage; dose selection should be cautious. Diarrhoea is the most common adverse reaction — if severe diarrhoea occurs, suspend dosing and rehydrate the patient. Paediatric (US label): IBS-C in patients 7 years of age and older — 145 micrograms orally once daily; functional constipation (FC) in patients 2 years of age and older — 72 micrograms orally once daily. CONTRAINDICATED in patients less than 2 years of age because of the risk of serious dehydration.

Dose auto-extracted from US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Patients less than 2 years of age, due to the risk of serious dehydration
Patients with known or suspected mechanical gastrointestinal obstruction

Side effects

Diarrhoea (most common, >=2% in adults with IBS-C or CIC; severe diarrhoea reported in 2% of adults treated with 145 or 290 micrograms once daily)
Abdominal pain
Flatulence
Abdominal distension
Diarrhoea is also the most common adverse reaction (>=2%) in paediatric patients 7-17 years with IBS-C and 6-17 years with FC

Clinical monograph

How it works

It activates guanylate cyclase-C on the intestinal epithelium, raising intracellular cyclic GMP, which increases secretion of chloride and bicarbonate into the lumen, accelerates transit and reduces visceral pain signalling.

Prescribing in practice

Diarrhoea is the most common adverse effect and can be severe; advise patients to stop and seek advice if it becomes severe or prolonged, particularly with dehydration risk.
It is contraindicated in known or suspected mechanical gastrointestinal obstruction.
Take on an empty stomach before the first meal of the day, and review treatment if there is no improvement after several weeks.

Monitoring

Routine laboratory monitoring is not required; monitor the clinical response and the severity of diarrhoea, reassessing if it is severe or persistent.

Counselling the patient

Take the capsule on an empty stomach, before your first meal of the day.
Diarrhoea can occur, especially early in treatment; stop and seek advice if it is severe or persistent.

Evidence & guidelines

Linaclotide is recommended by NICE as an option for moderate to severe irritable bowel syndrome with constipation in adults who meet specified criteria.

Reference: NICE CG61; 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.

Pathways