How it is administered

Tofacitinib is taken by mouth (orally). It is available in several forms:

• Immediate-release tablets (5 mg and 10 mg)
• Extended-release tablets (11 mg and 22 mg)
• Oral solution (1 mg/mL)

You can take tofacitinib with or without food. The extended-release tablets should be swallowed whole and not crushed, split, or chewed.

How it works

Tofacitinib is a Janus kinase (JAK) inhibitor. JAKs are enzymes inside your cells that help transmit signals from certain cytokines and growth factors, which are important in the immune system and blood cell formation. By blocking JAKs, tofacitinib disrupts these signals, which can reduce inflammation and abnormal immune responses.

This medication works by preventing the activation of proteins called STATs, which are involved in gene expression and immune cell function. By interfering with this pathway, tofacitinib helps to reduce the activity of the immune system, which can be helpful in diseases where the immune system is overactive, such as rheumatoid arthritis and other autoimmune conditions. However, this also means your immune system may not work as well to fight infections while you are taking this medication.

Who Should take it

Tofacitinib is approved for adults with:

• Moderately to severely active rheumatoid arthritis who have not responded well to other treatments (such as TNF blockers)
• Active psoriatic arthritis (when other treatments have not worked)
• Active ankylosing spondylitis (when other treatments have not worked)
• Moderately to severely active ulcerative colitis (when other treatments have not worked)
• Children (2 years and older) with active polyarticular course juvenile idiopathic arthritis (when other treatments have not worked)

It is not specifically approved for cutaneous T-cell lymphoma or other blood cancers, but your doctor may discuss it if they believe it could help based on your individual case.

Who should not take it

You should not take tofacitinib if you have:

• An absolute lymphocyte count less than 500 cells/mm³
• An absolute neutrophil count less than 1000 cells/mm³
• Hemoglobin less than 9 g/dL

It should also be avoided if you have a serious, active infection, including localized infections. Use caution if you have a history of chronic or recurrent infections, have been exposed to tuberculosis, or have underlying conditions that increase your risk of infection. Tofacitinib is not recommended for people with severe liver impairment.

Always discuss your full medical history with your doctor before starting tofacitinib.

Commonly used with

Tofacitinib is often used with other nonbiologic disease-modifying antirheumatic drugs (DMARDs), such as methotrexate, especially in the treatment of rheumatoid arthritis and psoriatic arthritis.

It should NOT be used in combination with biologic DMARDs or potent immunosuppressants like azathioprine or cyclosporine due to increased risk of serious side effects.

Commonly tested with

Tofacitinib has been tested in combination with other nonbiologic DMARDs (like methotrexate, sulfasalazine, and leflunomide) in clinical trials for autoimmune diseases.

It has also been compared to TNF blockers (such as adalimumab) in studies. However, it is not recommended to use tofacitinib together with biologic DMARDs or strong immunosuppressants due to safety concerns.