Infliximab; Uses, Dosage, Side Effects, Drug Interactions

Last updated: February 7, 2026Reviewed date: February 7, 2026Reading time: 6 min read
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Infliximab is a chimeric monoclonal antibody biologic drug that works against tumor necrosis factor alpha (TNF-α) and is used to treat autoimmune diseases. It is an antibody administered intravenously that is used for treating several chronic inflammatory diseases. Infliximab works by blocking the effects of tumor necrosis factor alpha (TNF alpha), a substance made by...

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বাংলা রোগী নোট এখনো যোগ করা হয়নি। পোস্ট এডিটরে “RX Bangla Patient Mode” বক্স থেকে সহজ বাংলা সারাংশ যোগ করুন।

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Article Summary

Infliximab is a chimeric monoclonal antibody biologic drug that works against tumor necrosis factor alpha (TNF-α) and is used to treat autoimmune diseases. It is an antibody administered intravenously that is used for treating several chronic inflammatory diseases. Infliximab works by blocking the effects of tumor necrosis factor alpha (TNF alpha), a substance made by cells of the body which has an important role in promoting inflammation. Infliximab injection is used in adults to treat Crohn disease, ulcerative colitis, rheumatoid...

Key Takeaways

  • This article explains Mechanism of action of Infliximab in simple medical language.
  • This article explains Indications of Infliximab in simple medical language.
  • This article explains Contra-Indications of Infliximab in simple medical language.
  • This article explains Dosage of Infliximab in simple medical language.
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Emergency safety firstUrgent warning signs are highlighted below.

Seek urgent medical care if you notice

These warning signs are general safety guidance. Local emergency numbers and clinical judgment should always come first.

  • Severe symptoms, breathing difficulty, fainting, confusion, or rapidly worsening illness.
  • New weakness, severe pain, high fever, or symptoms after a serious injury.
  • Any symptom that feels urgent, unusual, or unsafe for the patient.
1

Emergency now

Use emergency care for severe, sudden, rapidly worsening, or life-threatening symptoms.

2

See a doctor

Book a professional medical evaluation if symptoms persist, worsen, recur often, affect daily activities, or occur in a high-risk patient.

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Definition

Infliximab is a chimeric monoclonal antibody biologic drug that works against tumor necrosis factor alpha (TNF-α) and is used to treat autoimmune diseases. It is an antibody administered intravenously that is used for treating several chronic inflammatory diseases. Infliximab works by blocking the effects of tumor necrosis factor alpha (TNF alpha), a substance made by cells of the body which has an important role in promoting infection, or irritation, often causing pain, swelling, heat, or redness. সহজ বাংলা: শরীরের প্রদাহ; ব্যথা, ফোলা বা লালভাব হতে পারে।" data-rx-term="inflammation" data-rx-definition="Inflammation is the body’s response to injury, infection, or irritation, often causing pain, swelling, heat, or redness. সহজ বাংলা: শরীরের প্রদাহ; ব্যথা, ফোলা বা লালভাব হতে পারে।">inflammation. Infliximab injection is used in adults to treat Crohn disease, ulcerative colitis, stiffness, or reduced movement. সহজ বাংলা: জয়েন্টের প্রদাহ।" data-rx-term="arthritis" data-rx-definition="Arthritis means joint inflammation causing pain, swelling, stiffness, or reduced movement. সহজ বাংলা: জয়েন্টের প্রদাহ।">arthritis: Rheumatoid arthritis is an autoimmune joint disease causing inflammation, pain, and swelling. সহজ বাংলা: রোগপ্রতিরোধ ব্যবস্থার ভুল আক্রমণে জয়েন্টের প্রদাহ।" data-rx-term="rheumatoid arthritis" data-rx-definition="Rheumatoid arthritis is an autoimmune joint disease causing inflammation, pain, and swelling. সহজ বাংলা: রোগপ্রতিরোধ ব্যবস্থার ভুল আক্রমণে জয়েন্টের প্রদাহ।">rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, and chronic severe plaque psoriasis. It is also used in children to treat Crohn disease and ulcerative colitis. Infliximab injection is a monoclonal antibody that works to enhance and improve the immune system.

Infliximab works by binding to TNF-α. TNF-α is a chemical messenger (cytokine) and a key part of the autoimmune reaction. In pain, swelling, stiffness, or reduced movement. সহজ বাংলা: জয়েন্টের প্রদাহ।" data-rx-term="arthritis" data-rx-definition="Arthritis means joint inflammation causing pain, swelling, stiffness, or reduced movement. সহজ বাংলা: জয়েন্টের প্রদাহ।">arthritis: Rheumatoid arthritis is an autoimmune joint disease causing infection, or irritation, often causing pain, swelling, heat, or redness. সহজ বাংলা: শরীরের প্রদাহ; ব্যথা, ফোলা বা লালভাব হতে পারে।" data-rx-term="inflammation" data-rx-definition="Inflammation is the body’s response to injury, infection, or irritation, often causing pain, swelling, heat, or redness. সহজ বাংলা: শরীরের প্রদাহ; ব্যথা, ফোলা বা লালভাব হতে পারে।">inflammation, pain, and swelling. সহজ বাংলা: রোগপ্রতিরোধ ব্যবস্থার ভুল আক্রমণে জয়েন্টের প্রদাহ।" data-rx-term="rheumatoid arthritis" data-rx-definition="Rheumatoid arthritis is an autoimmune joint disease causing inflammation, pain, and swelling. সহজ বাংলা: রোগপ্রতিরোধ ব্যবস্থার ভুল আক্রমণে জয়েন্টের প্রদাহ।">rheumatoid arthritis, infliximab seems to work by preventing TNF-α from binding to its receptor in the cell.

Mechanism of action of Infliximab

Infliximab is aIgG1κ monoclonal antibody that binds to soluble and transmembrane forms of TNF-α with high affinity to disrupt the pro-inflammatory cascade signaling. Binding of the antibody to TNF-α prevents TNF-α from interacting with its receptors. Infliximab does not neutralize TNF-α (lymphotoxin-α), a related cytokine that utilizes the same receptors as TNF-α . Blocked actions of TNF-α further leads to downregulation of local and systemic pro-inflammatory cytokines (i.e. IL-1, IL-6), reduction of lymphocyte and infection. সহজ বাংলা: শ্বেত রক্তকণিকা।" data-rx-term="leukocyte" data-rx-definition="Leukocyte means white blood cell, which helps fight infection. সহজ বাংলা: শ্বেত রক্তকণিকা।">leukocyte migration to sites of pain, swelling, heat, or redness. সহজ বাংলা: শরীরের প্রদাহ; ব্যথা, ফোলা বা লালভাব হতে পারে।" data-rx-term="inflammation" data-rx-definition="Inflammation is the body’s response to injury, infection, or irritation, often causing pain, swelling, heat, or redness. সহজ বাংলা: শরীরের প্রদাহ; ব্যথা, ফোলা বা লালভাব হতে পারে।">inflammation, induction of apoptosis of TNF-producing cells (i.e. activated monocytes and T lymphocytes), increased levels of nuclear factor-κB inhibitor, and reduction of reduction of endothelial adhesion molecules and acute phase proteins . Its inhibitory actions on TNF-α was demonstrated in human fibroblasts, endothelial cells, neutrophils, B and Tlymphocytes and epithelial cells. Infliximab also atteunates the production of tissue degrading enzymes synthesized by synoviocytes and/or chondrocytes. According to a transgenic mice study that developed polyarthritis due to constitutive levels of human TNF-α, infliximab decreased synovitis and joint erosions in collagen-induced stiffness, or reduced movement. সহজ বাংলা: জয়েন্টের প্রদাহ।" data-rx-term="arthritis" data-rx-definition="Arthritis means joint inflammation causing pain, swelling, stiffness, or reduced movement. সহজ বাংলা: জয়েন্টের প্রদাহ।">arthritis and allows eroded joints to heal.

Indications of Infliximab

Contra-Indications of Infliximab

Dosage of Infliximab

Strengths: abda 100 mg; dyyb 100 mg; 100 mg

Rheumatoid Arthritis

  • 3 mg/kg given as an IV induction regimen at 0, 2, and 6 weeks followed by a maintenance regimen of 3 mg/kg IV every 8 weeks thereafter;
  • Adjusting the dose up to 10 mg/kg IV or treating as often as every 4 weeks may be considered for patients who have an incomplete response

Ankylosing Spondylitis

  • 5 mg/kg given as an IV induction regimen at 0, 2, and 6 weeks followed by a maintenance regimen of 5 mg/kg IV every 6 weeks thereafter

Psoriatic Arthritis

  • 5 mg/kg given as an IV induction regimen at 0, 2, and 6 weeks followed by a maintenance regimen of 5 mg/kg every 8 weeks thereafter

Psoriasis

  • 5 mg/kg given as an IV induction regimen at 0, 2, and 6 weeks followed by a maintenance regimen of 5 mg/kg IV every 8 weeks thereafter

Crohn’s Disease 

  • 5 mg/kg given as an IV induction regimen at 0, 2, and 6 weeks followed by a maintenance regimen of 5 mg/kg IV every 8 weeks thereafter; treatment with 10 mg/kg IV may be considered for patients who respond and then lose their response

Side Effects of Infliximab

The most common

More common

Rare

Drug Interactions of Infliximab

Infliximab may interact with the following drugs, supplements, & may change the efficacy of the drug

  • adalimumab
  • bacillus Calmette-Guérin (BCG)
  • belimumab
  • canakinumab
  • certolizumab pegol
  • live vaccines (e.g., measles, mumps, and rubella (MMR), tuberculosis (BCG), yellow fever)
  • cyclophosphamide
  • denosumab
  • fingolimod
  • leflunomide
  • nivolumab
  • natalizumab
  • pimecrolimus
  • roflumilast
  • sulfasalazine
  • tacrolimus
  • tocilizumab
  • tofacitinib
  • trastuzumab
  • vaccines (e.g., yellow fever, BCG, cholera, typhoid, varicella, meningococcal, diphtheria)

Pregnancy Catagory

FDA Pregnancy Category B

Pregnancy

This medication is not recommended for use during pregnancy. Women who may become pregnant should use an effective method of birth control while they are taking this medication and for at least 6 months after the last treatment.

Lactation

It is not known if infliximab passes into breast milk. Women should not breastfeed while they are taking this medication and should not start breastfeeding until at least 6 months after the last treatment. The safety and effectiveness of this medication have not been established for children under 6 years old. It can be used to treat children 6 years and older who have moderate-to-severe ulcerative colitis. It can also be used to treat children 9 years and older who have moderate-to-severe Crohn’s disease.

References

Infliximab; Uses, Dosage, Side Effects, Drug Interactions

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Safety note: This is not a prescription or diagnosis. For severe symptoms, pregnancy danger signs, children with serious illness, chest pain, breathing difficulty, stroke-like weakness, or major injury, seek urgent care.

Which doctor may help?

Dermatologist or general physician; emergency care for severe allergic reaction.

What to tell the doctor

  • Take photos of rash progression and bring list of new medicines/foods/cosmetics.

Questions to ask

  • Is this allergy, infection, eczema, psoriasis, drug reaction, or another skin disease?
  • Is steroid cream safe for this place and duration?

Tests to discuss

  • Skin examination
  • Skin scraping/KOH test if fungal infection is suspected
  • Biopsy only for unclear or serious lesions

Avoid these mistakes

  • Avoid unknown mixed creams, especially on face, groin, children, or pregnancy.
  • Seek urgent care for swelling of lips/face, breathing trouble, widespread blisters, or rash with fever.

Medicine safety and first-aid guide

This section is for patient education only. It does not replace a doctor, pharmacist, or emergency care.

Safe first steps

  • Avoid heavy lifting, sudden bending, and prolonged bed rest.
  • Use comfortable posture and gentle movement as tolerated.
  • Discuss physiotherapy, X-ray, or MRI only when clinically needed.

OTC medicine safety

  • For mild back pain, pain-relief medicine may be discussed with a doctor or pharmacist.
  • Avoid repeated painkiller use if you have kidney disease, stomach ulcer, uncontrolled blood pressure, or are taking blood thinners.

Avoid these mistakes

  • Do not start antibiotics without a proper medical decision.
  • Do not use steroid tablets or injections casually for quick relief.
  • Do not delay emergency care because of home remedies.

Get urgent help if

  • Back pain with leg weakness, numbness around private area, loss of urine/stool control, fever, cancer history, or major injury needs urgent care.
Medicine names, dose, and timing must be decided by a qualified clinician or pharmacist after checking age, pregnancy, allergy, other diseases, and current medicines.

For rural patients and family caregivers

Patient health record and symptom diary

Write your symptoms, medicines already taken, test results, and questions before visiting a doctor. This note stays on your device unless you print or copy it.

Doctor to discuss: Orthopedic / spine specialist, physical medicine doctor, or qualified clinician
Tests to discuss with doctor
  • Neurological examination for leg power, sensation, reflexes, and straight leg raise
  • X-ray only if injury, deformity, long-lasting pain, or doctor suspects bone problem
  • MRI discussion if severe nerve symptoms, weakness, bladder/bowel problem, or persistent symptoms
Questions to ask
  • What is the most likely cause of my symptoms?
  • Which warning signs mean I should go to emergency care?
  • Which tests are really needed now?
  • Which medicines are safe for my age, pregnancy status, allergy, kidney/liver/stomach condition, and current medicines?
  • Is physiotherapy, posture correction, or activity modification needed?

Emergency warning signs such as chest pain, severe breathing difficulty, sudden weakness, confusion, severe dehydration, major injury, or loss of bladder/bowel control need urgent medical care. Do not wait for online information.

Safe pathway to proper treatment

Care roadmap for: Infliximab; Uses, Dosage, Side Effects, Drug Interactions

Use this simple roadmap to understand the next safe steps. It is educational and does not replace examination by a doctor.

Go to emergency care if you notice:
  • Severe or rapidly worsening symptoms
  • Breathing difficulty, chest pain, fainting, confusion, severe weakness, major injury, or severe dehydration
Doctor / service to discuss: Qualified healthcare provider; specialist depends on symptoms and examination.
  1. Step 1

    Check danger signs first

    If danger signs are present, seek emergency care and do not wait for online information.

  2. Step 2

    Record the symptom story

    Write when symptoms started, severity, medicines already taken, allergies, pregnancy status, and test results.

  3. Step 3

    Visit a qualified clinician

    A doctor, nurse, or qualified healthcare provider can examine you and decide which tests or treatment are needed.

  4. Step 4

    Do only useful tests

    Do tests after clinical assessment. Avoid unnecessary tests, random antibiotics, or repeated medicines without diagnosis.

  5. Step 5

    Follow up and return early if worse

    If symptoms worsen, new warning signs appear, or treatment is not helping, return for review quickly.

Rural patient practical tips
  • Take a written symptom diary and all previous prescriptions/test reports.
  • Do not hide medicines already taken, even herbal or over-the-counter medicines.
  • Ask which warning signs mean urgent referral to hospital.

This roadmap is for education. A real diagnosis and treatment plan requires history, examination, and clinical judgment.

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Emergency first: Severe chest pain, breathing trouble, unconsciousness, stroke signs, severe injury, heavy bleeding, or rapidly worsening symptoms need urgent local medical care now.

Frequently Asked Questions

Is this article a replacement for a doctor?

No. It is educational content only. Patients should consult a qualified clinician for diagnosis and treatment.

When should I seek urgent care?

Seek urgent care for severe symptoms, rapidly worsening condition, breathing difficulty, severe pain, neurological changes, or any emergency warning sign.

References

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