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IBAT (apical sodium-bile acid transporter) inhibitor Pregnancy: Maternal use at the recommended clinical dose is not expected to result in measurable fetal exposure because systemic absorption after oral administration is low; no developmental effects were observed in animal reproduction studies. Maralixibat may inhibit the absorption of fat-soluble vitamins — monitor for deficiency and supplement as needed, and increased supplementation may be required during pregnancy (US labelling §8.1). No breast-feeding statement was captured in the fetched sections.

Maralixibat

Brand names: Livmarli

Maralixibat is an ileal bile acid transport inhibitor used for the treatment of cholestatic pruritus in children with Alagille syndrome and other specified cholestatic liver conditions.

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: Alagille syndrome (ALGS): 380 micrograms/kg once daily. Starting dose 190 micrograms/kg orally once daily, increased to 380 micrograms/kg once daily after one week, as tolerated
Route: Oral — 9.5 mg/mL oral solution for ALGS; tablets (10, 15, 20, 30 mg) may be used for ALGS or PFIC in patients weighing 25 kg and above who can swallow tablets. Take 30 minutes before a meal (in the morning for once-daily dosing)
Frequency: Once daily (ALGS)
Max: ALGS: must not exceed 28.5 mg (3 mL) per day for the oral solution or 30 mg per day for the tablets. PFIC: must not exceed 38 mg (2 mL) per day for the oral solution or 40 mg per day for the tablets
US LABELLING ONLY — no UK SPC was present in the bundle; verify against the UK SPC / EMA product information before publishing. Doses are in MICROGRAMS per kg. SECOND INDICATION — progressive familial intrahepatic cholestasis (PFIC): recommended dosage 570 micrograms/kg TWICE daily, 30 minutes before a meal; start at 285 micrograms/kg orally once daily in the morning, then increase to 285 micrograms/kg twice daily, then 428 micrograms/kg twice daily, then 570 micrograms/kg twice daily as tolerated. FORMULATION SAFETY: use the 9.5 mg/mL oral solution for ALGS and the 19 mg/mL oral solution for PFIC — the two strengths must NOT be substituted for one another when treating PFIC patients. Weight-band tables giving volume per dose (solution) and tablet strength per weight band are in the label and should be reproduced from it rather than calculated. Give special attention to accurate calculation of dose volume, particularly in patients under 5 years, as the oral solution contains propylene glycol 364.5 mg/mL. Missed dose — once-daily regimen: take within 12 hours of the usual time, otherwise omit and resume the original schedule; twice-daily regimen: take within 6 hours, otherwise omit. Safety and effectiveness have NOT been established in adult patients 65 years of age and older. Consider dose reduction or treatment interruption for liver test abnormalities, or for persistent diarrhoea or abdominal pain.

Paediatric dose

Dose: 380 micrograms/kg
Route: Oral — 9.5 mg/mL oral solution (ALGS), or tablets if weighing 25 kg and above and able to swallow tablets; 30 minutes before a meal in the morning
Frequency: Once daily
Max: 28.5 mg (3 mL) per day for the oral solution; 30 mg per day for the tablets
UNIT IS MICROGRAMS/kg, NOT mg/kg. This is the ALGS regimen: start at 190 micrograms/kg once daily and increase to 380 micrograms/kg once daily after one week as tolerated. Safety and effectiveness established in paediatric patients aged 3 months and older for ALGS; not established below 3 months. FOR PFIC THE REGIMEN IS DIFFERENT: 570 micrograms/kg TWICE daily (titrated 285 micrograms/kg once daily, then 285 micrograms/kg twice daily, then 428 micrograms/kg twice daily, then 570 micrograms/kg twice daily), maximum 38 mg/day for the oral solution or 40 mg/day for the tablets; established in paediatric patients aged 12 months and older; the 19 mg/mL solution must be used for PFIC to minimise propylene glycol exposure. US labelling — verify against the UK SPC and a children's formulary before prescribing.

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.

Paediatric weight-based calculator

UNIT IS MICROGRAMS/kg, NOT mg/kg. This is the ALGS regimen: start at 190 micrograms/kg once daily and increase to 380 micrograms/kg once daily after one week as tolerated. Safety and effectiveness established in paediatric patients aged 3 months and older for ALGS; not established below 3 months. FOR PFIC THE REGIMEN IS DIFFERENT: 570 micrograms/kg TWICE daily (titrated 285 micrograms/kg once daily, then 285 micrograms/kg twice daily, then 428 micrograms/kg twice daily, then 570 micrograms/kg twice daily), maximum 38 mg/day for the oral solution or 40 mg/day for the tablets; established in paediatric patients aged 12 months and older; the 19 mg/mL solution must be used for PFIC to minimise propylene glycol exposure. US labelling — verify against the UK SPC and a children's formulary before prescribing.

Verify in a children's formulary

Contraindications

  • Prior or active hepatic decompensation events (e.g. variceal haemorrhage, ascites, hepatic encephalopathy)

Side effects

  • Diarrhoea (most common, both indications)
  • Abdominal pain
  • Fat-soluble vitamin deficiency (may lead to fracture or bleeding)
  • Liver test abnormalities / hepatotoxicity — obtain baseline liver tests and monitor frequently for the first 6 to 8 months
  • Bone fractures
  • Vomiting (ALGS) and haematochezia (PFIC)

Interactions

  • Bile acid binding resins (e.g. cholestyramine, colesevelam, colestipol) — may bind maralixibat in the gut; administer maralixibat at least 4 hours before or 4 hours after the resin
  • OATP2B1 substrates (e.g. statins) — maralixibat is an OATP2B1 inhibitor in vitro and a decrease in their oral absorption cannot be ruled out; consider monitoring the effects of OATP2B1 substrates

Clinical monograph

How it works

It inhibits the apical sodium-dependent bile acid transporter in the terminal ileum, reducing reabsorption of bile acids and increasing their faecal elimination, which lowers serum bile acids and relieves cholestatic itch.

Prescribing in practice

  • Diarrhoea and disturbances of liver biochemistry can occur, so monitor liver tests and bile acids and follow the SPC guidance on interrupting or adjusting therapy if these worsen.
  • Because it reduces bile acid recycling, it may impair absorption of fat-soluble vitamins, which should be monitored and supplemented as needed.
  • It is used as a specialist treatment for cholestatic pruritus; consult a children's formulary and metabolic or hepatology specialists for dosing in the paediatric population.

Monitoring

Monitor liver function tests and serum bile acids at baseline and during treatment, together with fat-soluble vitamin status, under specialist supervision.

Counselling the patient

  • This medicine is given to relieve itching caused by liver disease; report worsening tummy upset, diarrhoea or yellowing of the skin or eyes.
  • Attend the scheduled blood tests so the team can monitor the liver and vitamin levels.

Evidence & guidelines

Ileal bile acid transport inhibitors are established for cholestatic pruritus in Alagille syndrome, having reduced serum bile acids and pruritus in controlled clinical trials.

Reference: NICE; 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).

Related

Curated clinical cross-links plus same-class fallbacks.

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