How it is administered

Tofacitinib is taken by mouth and 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 tablets should be swallowed whole and not split, crushed, or chewed. The oral solution is measured using a special dosing syringe provided with the medication.

How it works

Tofacitinib is a Janus kinase (JAK) inhibitor. JAKs are enzymes inside cells that help transmit signals from cytokines or growth factors, which are important for immune cell function and blood cell formation. By blocking JAKs, tofacitinib disrupts these signals, reducing inflammation and the activity of the immune system.

This action can help control overactive immune responses seen in certain autoimmune diseases. In clinical studies, tofacitinib has been shown to reduce the number of certain immune cells (like natural killer cells) and lower markers of inflammation in the blood. While it is not specifically approved for blood cancers, its effect on the immune system and blood cells is important to understand, especially if you have a history of blood cancers or are at risk.

Who Should take it

Tofacitinib is approved for adults with:

• Moderately to severely active rheumatoid arthritis
• Active psoriatic arthritis
• Active ankylosing spondylitis
• Moderately to severely active ulcerative colitis

It is also approved for children 2 years and older with polyarticular course juvenile idiopathic arthritis who have not responded well to other treatments. It is usually prescribed when other medications, like TNF blockers, have not worked or are not tolerated.

Tofacitinib is not specifically indicated for blood cancers, but if you have an autoimmune condition and a history of blood cancer, discuss with your doctor whether this medicine is appropriate for you.

Who should not take it

You should not take tofacitinib if:

• You have a very low lymphocyte count (<500 cells/mm³), neutrophil count (<1000 cells/mm³), or hemoglobin (<9 g/dL)
• You have a serious, active infection
• You are taking other strong immunosuppressive drugs (like azathioprine or cyclosporine) or biologic DMARDs

Caution is needed if you have a history of chronic infections, certain cancers (including blood cancers), or risk factors for blood clots or heart disease. Always discuss your full medical history with your doctor before starting tofacitinib.

Commonly used with

Tofacitinib is often used with nonbiologic disease-modifying antirheumatic drugs (DMARDs), such as methotrexate, especially for rheumatoid and psoriatic arthritis. It should not be used with other biologic DMARDs or potent immunosuppressants due to the risk of added immunosuppression.

Commonly tested with

In clinical trials, tofacitinib has been tested with methotrexate and other nonbiologic DMARDs. It has also been compared to TNF blockers (such as adalimumab) in studies. It is not recommended to use tofacitinib with other potent immunosuppressants or biologic therapies.