Tofacitinib is an oral immunomodulatory medicine belonging to the Janus kinase (JAK) inhibitor class. It is used in the treatment of moderate to severe ulcerative colitis, rheumatoid arthritis, psoriatic arthritis, and certain other autoimmune inflammatory conditions. Tofacitinib works by blocking specific intracellular enzymes involved in immune signalling, thereby reducing inflammation, immune overactivity, and tissue damage. It is particularly useful in patients who have not responded adequately to conventional therapies or biologic medicines.

Tofacitinib is a targeted synthetic disease-modifying anti-rheumatic drug (tsDMARD). Unlike traditional immunosuppressants that broadly dampen immune function, Tofacitinib works at a molecular level inside immune cells. It inhibits Janus kinase (JAK) enzymes, which play a key role in transmitting inflammatory signals from cytokines involved in autoimmune diseases.

Autoimmune conditions such as ulcerative colitis and rheumatoid arthritis occur when the immune system mistakenly attacks the body’s own tissues. This leads to chronic inflammation, pain, swelling, and progressive tissue damage. In ulcerative colitis, inflammation affects the lining of the colon and rectum, causing symptoms such as persistent diarrhoea, abdominal pain, rectal bleeding, urgency, and fatigue. In arthritis, inflammation targets the joints, leading to pain, stiffness, swelling, and reduced mobility.

By inhibiting JAK pathways, Tofacitinib interrupts the signalling of multiple pro-inflammatory cytokines, including interleukins and interferons. This reduces immune-mediated inflammation, helps control symptoms, promotes mucosal healing in ulcerative colitis, and prevents further joint damage in inflammatory arthritis.

Tofacitinib is taken orally, offering a convenient alternative to injectable biologic therapies. It is typically prescribed when patients have had an inadequate response or intolerance to conventional disease-modifying medicines or biologic agents. Due to its immunomodulatory effects, patients receiving Tofacitinib require careful monitoring, including blood tests, infection screening, and cardiovascular risk assessment.

When used appropriately under specialist supervision, Tofacitinib can significantly improve disease control, quality of life, and long-term outcomes for people living with chronic inflammatory diseases.

Tofacitinib is indicated for:

Induction of Remission in Moderate to Severe Ulcerative Colitis (UC):

Used to control active disease in patients who have had an inadequate response, loss of response, or intolerance to conventional therapy or biologic medicines. It helps reduce inflammation, control symptoms, and promote mucosal healing.

Maintenance of Remission in Ulcerative Colitis:

Helps maintain long-term disease control after remission has been achieved, reducing the risk of relapse and improving quality of life.

Treatment of Rheumatoid Arthritis:

Used in adults with moderate to severe rheumatoid arthritis who have responded inadequately to methotrexate or other conventional disease-modifying antirheumatic drugs (DMARDs).

Treatment of Psoriatic Arthritis:

Helps reduce joint pain, swelling, stiffness, and skin symptoms in patients with active psoriatic arthritis.

Targeted Immune Modulation:

Inhibits Janus kinase (JAK) pathways involved in inflammatory signalling, reducing immune-driven inflammation at its source rather than broadly suppressing the immune system.

Effective in Difficult-to-Treat Disease:

Particularly beneficial for patients with ulcerative colitis or inflammatory arthritis who have not responded adequately to conventional treatments or biologic therapies.

Oral Therapy Convenience:

Available as a tablet, offering a convenient alternative to injectable or infusion-based biologic medicines.

Rapid Symptom Control:

Many patients experience improvement in symptoms such as diarrhoea, rectal bleeding, joint pain, and stiffness within weeks of starting treatment.

Supports Long-Term Disease Control:

Helps maintain remission, prevent flare-ups, and reduce disease progression when used with appropriate monitoring.

When taken as prescribed and under specialist supervision, Tofacitinib can be effective, but it may cause side effects due to its immunomodulatory action.

Common Side Effects (Usually Mild to Moderate)

• Headache

• Nausea

• Diarrhoea

• Upper respiratory tract infections (e.g. common cold)

• Increased cholesterol levels

• Mild elevations in liver enzymes

Serious Side Effects

Stop taking the medicine and seek urgent medical attention if you experience:

• Serious Infections: Fever, persistent cough, shortness of breath, or unexplained weight loss (risk of tuberculosis, shingles, or other serious infections).

• Blood Clots: Sudden chest pain, difficulty breathing, swelling or pain in the legs.

• Cardiovascular Events: Symptoms of a heart attack or stroke, such as chest pain, weakness on one side of the body, or difficulty speaking.

• Severe Allergic Reactions: Rash, swelling of the face, lips, tongue, or throat, dizziness, or breathing difficulties.

• Blood Disorders: Unusual bruising, bleeding, or signs of low white blood cell counts.

Regular monitoring and prompt reporting of symptoms are essential to ensure safe and effective use of Tofacitinib.

• Take exactly as prescribed by your specialist.

• Swallow tablets whole with water.

• Can be taken with or without food.

• Take doses at the same time each day.

• Do not stop treatment suddenly without medical advice.

Tofacitinib works by modulating the immune system at a cellular level, rather than acting locally in the gut. It belongs to the class of Janus kinase (JAK) inhibitors and exerts its effects inside immune cells that drive chronic inflammation.

• Intracellular Targeting: Tofacitinib inhibits Janus kinase enzymes (primarily JAK1 and JAK3), which are essential for transmitting inflammatory signals from cytokine receptors on the cell surface to the nucleus.

• Cytokine Signal Blockade: By blocking JAK pathways, Tofacitinib interrupts the signalling of multiple pro-inflammatory cytokines such as interleukins and interferons that are responsible for immune activation in ulcerative colitis and inflammatory arthritis.

• Reduction of Immune Overactivity: This inhibition reduces the activation, proliferation, and survival of immune cells involved in inflammation, thereby decreasing tissue damage.

• Anti-Inflammatory Effect in Target Organs: In ulcerative colitis, this leads to reduced inflammation of the colonic lining and promotes mucosal healing. In arthritis, it reduces joint inflammation, pain, and structural damage.

• Systemic but Targeted Action: Unlike conventional immunosuppressants, Tofacitinib selectively targets specific immune signalling pathways rather than causing broad immune suppression.

• Complete all infection screening before starting therapy

• Report fever, cough, or unexplained weight loss immediately

• Attend regular blood tests for safety monitoring

• Avoid live vaccines during treatment

• Maintain heart-healthy lifestyle habits

• Store below 25°C

• Keep away from moisture and heat

• Keep out of reach of children

• No major food interactions.

• Grapefruit may affect metabolism. Use with caution.

• Other Immunosuppressants or Biologics: Increased risk of serious infections (generally avoided).

• Strong CYP3A4 Inhibitors (e.g. Ketoconazole): May increase Tofacitinib levels. Dose adjustment required.

• Strong CYP3A4 Inducers (e.g. Rifampicin): May reduce effectiveness of Tofacitinib.

• Live Vaccines: Contraindicated during treatment due to infection risk.

• Active or Chronic Infections: Increased risk of severe infection.

• Cardiovascular Disease: Increased risk of heart attack and stroke in high-risk patients.

• History of Blood Clots: Increased risk of venous thromboembolism.

• Liver Disease: Risk of hepatotoxicity; close monitoring required.

• Malignancy History: Use with caution due to increased cancer risk with long-term

Dose depends on indication and patient factors. For ulcerative colitis, higher induction doses may be used initially, followed by a lower maintenance dose. Always follow specialist advice.

Symptoms may include severe infections or laboratory abnormalities. Seek immediate medical attention.

Take the missed dose as soon as remembered unless it is close to the next dose. Do not double doses.