Anti-IL-12/23 Monoclonal Antibody Pregnancy: Limited data — ustekinumab crosses placenta. Consider risks vs benefits. Avoid live vaccines in neonate for 6 months if exposed in utero in third trimester.

Ustekinumab

Brand names: Stelara

Adult dose

Dose: Induction (IV, weight-based, single dose): body weight ≤55kg: 260mg; 55–85kg: 390mg; >85kg: 520mg. Maintenance: 90mg SC at week 8 after induction, then every 12 weeks. Inadequate response: reduce interval to every 8 weeks.

Route: IV (induction); subcutaneous (maintenance)

Frequency: Induction: single IV dose. Maintenance: every 12 weeks SC (or every 8 weeks if needed)

Max: 520mg IV (induction); 90mg SC per maintenance dose

Targets IL-12 and IL-23 (p40 subunit) — blocks Th1 and Th17 pathways. Gut-selective inflammation mechanism. Lower infection risk than anti-TNF. No TB screening required per se, but standard pre-biologic infection screen recommended. NICE TA456 (Crohn's), NICE TA739 (UC).

Paediatric dose

Route: N/A

Frequency: N/A

Max: Not licensed in children <18 years for IBD

Not licensed in patients <18 years for Crohn's or UC. Off-label use in specialist paediatric IBD centres. Seek specialist opinion.

Dose adjustments

Renal

No dose adjustment required.

Hepatic

No dose adjustment required.

Clinical pearls

Lower infection risk than anti-TNF — preferred in patients with recurrent infections, elderly patients, or those with prior TB or malignancy.
Onset is slower than anti-TNF — not suitable for severe acute flares requiring rapid response.
Positioning in IBD: NICE TA456 — recommended for Crohn's after failure of conventional and at least one anti-TNF therapy, or when anti-TNF is contraindicated.
Maintenance interval: start at every 12 weeks SC; shorten to every 8 weeks if loss of response — check drug levels before escalating.

Contraindications

Active TB or serious active infection
Live vaccines during treatment

Side effects

Nasopharyngitis, upper respiratory tract infection
Headache
Injection site reactions
Arthralgia
Serious infections (lower rate than anti-TNF)
Reversible posterior leukoencephalopathy syndrome (RPLS — extremely rare)

Interactions

Live vaccines: contraindicated during treatment
CYP450 substrates: ustekinumab may normalise CYP450 enzymes suppressed by IL-12/23 — monitor drugs metabolised by CYP450 (e.g., warfarin, ciclosporin) after starting

Monitoring

Disease activity (Harvey-Bradshaw Index or Mayo score)
CRP and faecal calprotectin
Drug trough levels (if loss of response)
Signs of infection
Skin cancer surveillance (annual)

Reference: BNFc; BNF 90; NICE TA456 (Crohn's — Ustekinumab); NICE TA739 (UC — Ustekinumab); ECCO IBD Guidelines 2021. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Drugs

Ustekinumab · Anti-IL-12/23 Monoclonal Antibody

Pathways