INFLECTRA

Clinical safety rating: caution

Comprehensive clinical and safety monograph for INFLECTRA (INFLECTRA).

How it works

Infliximab is a chimeric monoclonal antibody that binds with high affinity to soluble and transmembrane forms of tumor necrosis factor alpha (TNF-α), thereby neutralizing its pro-inflammatory activity and reducing TNF-α-mediated signaling.

What the body does with it

Metabolism	Infliximab is a monoclonal antibody, not metabolized by cytochrome P450 enzymes; clearance occurs via cellular catabolism and reticuloendothelial system.
Excretion	Primarily metabolized via proteolysis; no significant renal or hepatic elimination. Less than 0.1% excreted unchanged in urine. Fecal elimination is negligible.
Half-life	Terminal half-life approximately 7-12 days (median 9.5 days). In patients with ulcerative colitis, half-life may be shorter (about 5-7 days).
Protein binding	Approximately 90% bound to plasma proteins, primarily immunoglobulins (IgG1) and albumin.
Volume of Distribution	Central volume of distribution approximately 3-4 L; Vd at steady state is about 3.0 L (0.04 L/kg) reflecting distribution primarily in the vascular space.
Bioavailability	Not applicable for IV route (100% bioavailability). No other routes of administration are approved.
Onset of Action	IV: Clinical improvement may occur within 2 weeks; radiological improvement may take longer.
Duration of Action	Variable; therapeutic effect typically lasts 8 weeks, but may diminish over time due to antibody development and clearance leading to loss of response.

Classification & Brands

Dosing & administration

5 mg/kg IV infusion at 0, 2, and 6 weeks, then every 8 weeks.

Dosage form	INJECTABLE
Renal impairment	No dosage adjustment required for renal impairment.
Liver impairment	No formal studies; use caution in moderate to severe hepatic impairment (Child-Pugh B or C).
Pediatric use	For children ≥6 years: 5 mg/kg IV at 0, 2, and 6 weeks, then every 8 weeks.
Geriatric use	No specific dose adjustment; monitor for infections and infusion reactions.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for INFLECTRA (INFLECTRA).

Breastfeeding

Infliximab is excreted into breast milk in very low amounts (estimated relative infant dose <1% of maternal dose). No adverse effects reported in breastfed infants. M/P ratio not available due to undetectable levels in milk in most studies. Advantages of breastfeeding outweigh theoretical risks in moderate-to-severe inflammatory bowel disease. Monitor infant for infections.

Teratogenic Risk

Infliximab (INFLECTRA) is an IgG1 monoclonal antibody that crosses the placenta only after the first trimester, with increasing transfer during the second and third trimesters. First trimester exposure: No consistent evidence of major malformations above baseline (2-3%). Second/third trimester exposure: Fetal and neonatal exposure may increase risk of infections; live vaccines should be withheld in infants for at least 6 months after last maternal dose. Based on human data, no specific teratogenic pattern has been identified, but limited data exist.

Warnings & precautions

■ FDA Black Box Warning

Serious and sometimes fatal infections (including tuberculosis, bacterial sepsis, invasive fungal infections, and opportunistic infections) have been reported; increased risk of lymphoma and other malignancies, particularly hepatosplenic T-cell lymphoma in adolescents and young adults with inflammatory bowel disease.

Side Effect Profile

Serious Effects

Absolute Contraindications

Hypersensitivity to infliximab or any murine proteins, severe infections (e.g., sepsis, abscess, tuberculosis, opportunistic infections), moderate to severe heart failure (NYHA Class III/IV).

Clinical Precautions

Precautions

Hypersensitivity reactions (including anaphylaxis), infusion reactions, exacerbation of congestive heart failure, hepatotoxicity, hematologic cytopenias, demyelinating disorders, and increased risk of infection. Live vaccines should not be administered concurrently.

Clinical Tips & Counseling

Drug interactions

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INFLECTRA

Clinical safety rating: caution

Comprehensive clinical and safety monograph for INFLECTRA (INFLECTRA).

How it works

What the body does with it

Metabolism	Infliximab is a monoclonal antibody, not metabolized by cytochrome P450 enzymes; clearance occurs via cellular catabolism and reticuloendothelial system.
Excretion	Primarily metabolized via proteolysis; no significant renal or hepatic elimination. Less than 0.1% excreted unchanged in urine. Fecal elimination is negligible.
Half-life	Terminal half-life approximately 7-12 days (median 9.5 days). In patients with ulcerative colitis, half-life may be shorter (about 5-7 days).
Protein binding	Approximately 90% bound to plasma proteins, primarily immunoglobulins (IgG1) and albumin.
Volume of Distribution	Central volume of distribution approximately 3-4 L; Vd at steady state is about 3.0 L (0.04 L/kg) reflecting distribution primarily in the vascular space.
Bioavailability	Not applicable for IV route (100% bioavailability). No other routes of administration are approved.
Onset of Action	IV: Clinical improvement may occur within 2 weeks; radiological improvement may take longer.
Duration of Action	Variable; therapeutic effect typically lasts 8 weeks, but may diminish over time due to antibody development and clearance leading to loss of response.

Classification & Brands

Dosing & administration

5 mg/kg IV infusion at 0, 2, and 6 weeks, then every 8 weeks.

Dosage form	INJECTABLE
Renal impairment	No dosage adjustment required for renal impairment.
Liver impairment	No formal studies; use caution in moderate to severe hepatic impairment (Child-Pugh B or C).
Pediatric use	For children ≥6 years: 5 mg/kg IV at 0, 2, and 6 weeks, then every 8 weeks.
Geriatric use	No specific dose adjustment; monitor for infections and infusion reactions.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for INFLECTRA (INFLECTRA).

Breastfeeding

Teratogenic Risk

Warnings & precautions

■ FDA Black Box Warning

Side Effect Profile

Serious Effects

Absolute Contraindications

Hypersensitivity to infliximab or any murine proteins, severe infections (e.g., sepsis, abscess, tuberculosis, opportunistic infections), moderate to severe heart failure (NYHA Class III/IV).