Uses

A Janus kinase (JAK) inhibitor indicated for adults with moderately to severely active rheumatoid arthritis, active psoriatic arthritis, or active ankylosing spondylitis who have had inadequate response or intolerance to one or more TNF blockers. Also indicated for moderately to severely active ulcerative colitis.

Do not use if

No absolute contraindications per the FDA label; however, use is not recommended in patients with active serious infections or severe hepatic impairment. Requires careful evaluation of benefit-risk in patients with cardiovascular risk, malignancy history, or thrombosis risk.

Side effects

Serious infections (including tuberculosis and opportunistic infections), increased mortality risk (especially in patients over 50 with cardiovascular risk factors), malignancies, major adverse cardiovascular events (MACE), thrombosis (DVT/PE), elevated liver enzymes, and cytopenias. Common effects include upper respiratory infections, headache, and diarrhea.

Warnings

Black box warning: increased risk of serious infections, mortality, malignancy (including lymphoma and lung cancer), MACE, and thrombosis. Use lowest effective dose. Perform tuberculosis screening before initiation. Not recommended in combination with other JAK inhibitors or biologic DMARDs. Use in patients aged ≥50 with cardiovascular risk factors requires careful consideration.

How it works

Tofacitinib inhibits JAK1 and JAK3 (and to a lesser extent JAK2), blocking the JAK-STAT signaling pathway. This reduces the phosphorylation and activation of STAT proteins, thereby attenuating inflammatory cytokine signaling and modulating immune cell function involved in the pathogenesis of rheumatoid arthritis and other inflammatory diseases.

Storage

Store at room temperature between 20°C and 25°C (68°F–77°F); excursions permitted to 15°C–30°C.