Peripheral μ-opioid receptor antagonist Pregnancy: Use is not recommended during pregnancy — limited data in pregnant women, animal reproductive toxicity at exposures several times therapeutic, and a theoretical potential for provoking opioid withdrawal in the foetus. Use in breast-feeding mothers is not recommended.

Naloxegol

Brand names: Moventig

Naloxegol is an orally administered, peripherally acting mu-opioid receptor antagonist used for opioid-induced constipation in adults with an inadequate response to laxatives.

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: 25 mg once daily

Route: Oral — take on an empty stomach at least 30 minutes prior to the first meal of the day or 2 hours after the first meal of the day

Frequency: Once daily; recommended in the morning, for patient convenience to avoid bowel movements in the middle of the night

May be used with or without laxatives. Treatment must be withdrawn when systemic opioid therapy is stopped. Moderate CYP3A4 inhibitors (e.g. diltiazem, verapamil): starting dose 12.5 mg once daily, which can be increased to 25 mg if 12.5 mg is well tolerated; no dose adjustment for weak CYP3A4 inhibitors (e.g. alprazolam, atorvastatin). Elderly: no dose adjustment recommended based on age. Cancer-related pain: no dose adjustment required. Hepatic impairment: no dose adjustment for mild to moderate impairment; use in severe hepatic impairment is not recommended (safety and efficacy not established). Paediatric: safety and efficacy in children under 18 years has not yet been established, no data available. For patients unable to swallow the tablet whole, it can be crushed to a powder, mixed in half a glass of water (120 mL) and drunk immediately, then the glass rinsed with a further half glass of water (120 mL) and the contents drunk; see SPC §6.6 for nasogastric tube administration.

Dose adjustments

Renal

Starting dose for patients with moderate or severe renal insufficiency is 12.5 mg; the dose can be increased to 25 mg if 12.5 mg is well tolerated. If side effects impacting tolerability occur, naloxegol should be discontinued. No dosage adjustment is required for mild renal impairment.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; 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

Hypersensitivity to the active substance, to any of the excipients, or to any other opioid antagonist
Known or suspected gastrointestinal obstruction, or patients at increased risk of recurrent obstruction, due to the potential for gastrointestinal perforation
Patients with underlying cancer at heightened risk of gastrointestinal perforation — underlying malignancies of the gastrointestinal tract or peritoneum, recurrent or advanced ovarian cancer, or vascular endothelial growth factor (VEGF) inhibitor treatment
Concomitant use with strong CYP3A4 inhibitors (e.g. clarithromycin, ketoconazole, itraconazole, telithromycin; protease inhibitors such as ritonavir, indinavir or saquinavir; grapefruit juice when consumed in large quantities)

Side effects

Abdominal pain (very common)
Diarrhoea (very common)
Nausea and vomiting (common)
Flatulence (common)
Headache (common); nasopharyngitis; opioid withdrawal syndrome and gastrointestinal perforation reported (uncommon/rare)

Interactions

Strong CYP3A4 inhibitors (clarithromycin, ketoconazole, itraconazole, telithromycin, ritonavir, indinavir, saquinavir; large quantities of grapefruit juice) — contraindicated (§4.3)
Moderate CYP3A4 inhibitors (e.g. diltiazem, verapamil) — starting dose reduced to 12.5 mg once daily, increased to 25 mg only if 12.5 mg is well tolerated (§4.2)
Weak CYP3A4 inhibitors (e.g. alprazolam, atorvastatin) — no dose adjustment required (§4.2)
Methadone — patients taking methadone as primary therapy for their pain condition had a higher frequency of gastrointestinal adverse reactions and, in a few cases, symptoms suggestive of opioid withdrawal at the 25 mg dose (§4.4)
NOTE: the eMC §4.5 interaction section was not captured in the fetched bundle — clinician to review the full SPC §4.5 before publication

Clinical monograph

How it works

A pegylated derivative of naloxone, it antagonises mu-opioid receptors in the gut while its minimal central penetration preserves opioid analgesia.

Prescribing in practice

Contraindicated in known or suspected gastrointestinal obstruction and where there is increased risk of perforation.
It is a CYP3A4 substrate, so avoid strong inhibitors and inducers and grapefruit, and take it on an empty stomach as directed in the SPC.
Stop if the opioid is discontinued and review if severe gastrointestinal symptoms occur.

Monitoring

Monitor for severe abdominal pain, diarrhoea and possible opioid withdrawal symptoms, and review concomitant medicines for CYP3A4 interactions.

Counselling the patient

Advise patients to take the medicine on an empty stomach, typically before the first meal of the day, and to avoid grapefruit.
Tell patients to report severe or persistent abdominal pain and to seek advice before adding new medicines.

Evidence & guidelines

Naloxegol is recommended by NICE for opioid-induced constipation in adults who have not responded adequately to laxatives.

Reference: NICE TA651; SmPC; 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.

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