Anti-TNF-α monoclonal antibody Pregnancy: Should only be used during pregnancy if clearly needed. Approximately 1,100 first-trimester exposures do not indicate an increase in the rate of malformation, but an observational study found increased odds of caesarean section, preterm birth, small for gestational age and low birth weight. Infliximab crosses the placenta and has been detected in infant serum up to 12 months after birth - exposed infants may be at increased risk of infection, including serious disseminated infection that can become fatal, and live vaccines (e.g. BCG) are not recommended for 12 months after birth. Women of childbearing potential should consider adequate contraception during treatment and for at least 6 months after the last infliximab treatment. Breast-feeding: infliximab is detected at low levels in human milk (up to 5% of maternal serum level) and in infant serum; live vaccines are not recommended for a breastfed infant while the mother is receiving infliximab.

Infliximab

Brand names: Remicade, Inflectra, Remsima, Flixabi, Zessly

Infliximab is a chimeric anti-TNF-alpha monoclonal antibody given by intravenous infusion (with a subcutaneous formulation also available). It is used in inflammatory arthritis, inflammatory bowel disease, psoriasis and related immune-mediated 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: Adults (18 years and over). Rheumatoid arthritis: 3 mg/kg bodyweight by intravenous infusion, followed by further 3 mg/kg infusions at 2 and 6 weeks after the first infusion, then every 8 weeks thereafter - must be given concomitantly with methotrexate. Crohn disease (moderate to severe, and fistulising), ulcerative colitis, ankylosing spondylitis, psoriatic arthritis and psoriasis: 5 mg/kg bodyweight by intravenous infusion, followed by further 5 mg/kg infusions at 2 and 6 weeks after the first infusion, then every 8 weeks thereafter (ankylosing spondylitis: then every 6 to 8 weeks)

Route: Intravenous infusion over a 2 hour period, given by qualified healthcare professionals trained to detect infusion-related issues; observe all patients for at least 1-2 hours post-infusion for acute infusion-related reactions, with emergency equipment (adrenaline, antihistamines, corticosteroids and an artificial airway) available. Treatment must be initiated and supervised by qualified physicians experienced in the relevant disease. The US label (INFLECTRA) additionally specifies infusion via an in-line filter

Frequency: Induction at 0, 2 and 6 weeks, then maintenance every 8 weeks (ankylosing spondylitis every 6 to 8 weeks)

Max: Rheumatoid arthritis: for inadequate or lost response after 12 weeks, the dose may be increased step-wise by approximately 1.5 mg/kg up to a MAXIMUM OF 7.5 mg/kg every 8 weeks (alternatively 3 mg/kg as often as every 4 weeks). INFUSION-RATE CEILING: infusions are given over 2 hours; a shortened infusion of not less than 1 hour may be considered only in carefully selected adults who have tolerated at least 3 initial 2-hour infusions and are on maintenance therapy - shortened infusions at doses above 6 mg/kg have not been studied

Source: Flixabi 100 mg powder for concentrate for solution for infusion. Optimise other concomitant therapies (e.g. corticosteroids and immunosuppressants) during treatment. Patients should be given the package leaflet and the patient reminder card. RHEUMATOID ARTHRITIS: clinical response is usually achieved within 12 weeks; continued therapy should be carefully reconsidered if there is no evidence of therapeutic benefit within the first 12 weeks or after dose adjustment. CROHN DISEASE (moderate to severe): if a patient does not respond after 2 doses, no additional infliximab should be given, and available data do not support further treatment in patients not responding within 6 weeks of the initial infusion; responders may continue with maintenance (additional 5 mg/kg at 6 weeks then every 8 weeks) or re-administration (5 mg/kg if signs and symptoms recur). FISTULISING CROHN DISEASE: 5 mg/kg at 0, 2 and 6 weeks - if no response after 3 doses, no additional treatment should be given; responders continue 5 mg/kg every 8 weeks. ULCERATIVE COLITIS: response usually achieved within 14 weeks (three doses) - reconsider if no benefit by then. ANKYLOSING SPONDYLITIS: if no response by 6 weeks (after 2 doses), no additional treatment should be given. PSORIASIS: if no response after 14 weeks (4 doses), no additional treatment should be given; re-treatment after a 20-week interval suggests reduced efficacy and more infusion-related reactions. RE-ADMINISTRATION: for Crohn disease and rheumatoid arthritis, infliximab can be re-administered within 16 weeks of the last infusion - safety and efficacy of re-administration after an infliximab-free interval of more than 16 weeks has not been established. If maintenance therapy is interrupted across any indication, a re-induction regimen is NOT recommended - re-initiate as a single dose followed by the maintenance recommendations. Patients may be pre-treated with e.g. an antihistamine, hydrocortisone and/or paracetamol, and the infusion rate may be slowed, to decrease the risk of infusion-related reactions, especially if these have occurred previously. ELDERLY: no dose adjustment is required. Infusion volumes/preparation: see SPC §6.6.

Paediatric dose

Dose: 5 mg/kg

Route: Intravenous infusion over a 2 hour period

Frequency: At 0, 2 and 6 weeks, then every 8 weeks thereafter

Max: No paediatric dose ceiling is stated in this SPC (the 7.5 mg/kg ceiling applies to the adult rheumatoid arthritis escalation only)

Applies ONLY to Crohn disease and ulcerative colitis in patients aged 6 to 17 years. Crohn disease: available data do not support further treatment in children and adolescents not responding within the first 10 weeks. Ulcerative colitis: available data do not support further treatment in paediatric patients not responding within the first 8 weeks. Some patients may require a shorter dosing interval to maintain clinical benefit and others a longer one; patients whose dose interval has been shortened to less than 8 weeks may be at greater risk of adverse reactions. Safety and efficacy have NOT been studied in children below 6 years with Crohn disease or ulcerative colitis and no posology recommendation can be made. Safety and efficacy are NOT established under 18 years for psoriasis, juvenile idiopathic arthritis, psoriatic arthritis, ankylosing spondylitis or juvenile rheumatoid arthritis - no posology recommendation can be made. Verify all paediatric dosing against a children formulary and specialist advice.

Dose adjustments

Renal

Infliximab has not been studied in patients with renal and/or hepatic impairment - no dose recommendations can be made.

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.

Paediatric weight-based calculator

Patient weight (kg)

Verify in a children's formulary

Contraindications

Hypersensitivity to infliximab, to other murine proteins, or to any of the excipients
Patients with tuberculosis or other severe infections such as sepsis, abscesses and opportunistic infections
Patients with moderate or severe heart failure (NYHA class III/IV)

Side effects

Upper respiratory tract infection - the most common adverse reaction, in 25.3% of infliximab-treated patients versus 16.5% of controls
Viral infection, e.g. influenza and herpes virus infection (very common); bacterial infections such as sepsis, cellulitis and abscess (common)
Serious and opportunistic infections, including tuberculosis (uncommon), fungal infections, and hepatitis B reactivation (rare)
Serious infusion-related reactions and serum sickness (delayed hypersensitivity reactions)
Congestive heart failure, haematologic reactions, systemic lupus erythematosus / lupus-like syndrome, demyelinating disorders and hepatobiliary events
Malignancy - lymphoma, non-Hodgkin lymphoma, Hodgkin disease, leukaemia, hepatosplenic T-cell lymphoma, Merkel cell carcinoma, melanoma and paediatric malignancy (rare)

Interactions

Live vaccines - administration of live vaccines (e.g. BCG) to infants exposed to infliximab in utero is not recommended for 12 months after birth; live vaccines are also not recommended for a breastfed infant while the mother is receiving infliximab (§4.6)
Anakinra or abatacept - combination with infliximab is not recommended; an increased risk of serious infections was seen with other TNF blockers plus anakinra or abatacept, with no added clinical benefit (US INFLECTRA label §7.1; eMC §4.5 was not retrieved in this fetch)
Tocilizumab and other biological DMARDs - concomitant use with a TNF antagonist should be avoided because of possible increased immunosuppression and increased risk of infection (US INFLECTRA label §7.1)
Other biological products used to treat the same conditions - combination not recommended (US INFLECTRA label §7.1)
Methotrexate - no specific drug interaction studies have been conducted; infliximab must nonetheless be given concomitantly with methotrexate in rheumatoid arthritis (§4.2)

Clinical monograph

How it works

It binds and neutralises soluble and membrane-bound tumour necrosis factor alpha, blocking a key pro-inflammatory cytokine and reducing inflammation.

Prescribing in practice

Screen for latent tuberculosis, hepatitis B and active infection before starting, as anti-TNF therapy can reactivate tuberculosis and serious infection.
Avoid in moderate to severe heart failure, as anti-TNF agents can worsen it.
Avoid live vaccines during treatment and review the patient's vaccination status beforehand.

Monitoring

Monitor for infection, infusion reactions and, where clinically indicated, full blood count and liver function during therapy.

Counselling the patient

Report fever, night sweats, persistent cough or weight loss, which may signal infection or tuberculosis.
Seek urgent help for breathing difficulty, rash or other symptoms during or shortly after an infusion.
Tell other healthcare professionals you are taking a biologic that suppresses the immune system.

Evidence & guidelines

NICE recommends anti-TNF therapy including infliximab for several immune-mediated inflammatory diseases within specified criteria.

Reference: NICE TA163/TA329/TA199; BSR guidelines; 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.

Calculators

Pathways