Tofacitinib
Also known as: Xeljanz · Tofacitinib citrate
Tofacitinib is a tablet, not an injection, and that appeals to many patients. It was the first JAK inhibitor in rheumatology, so it also has the longest safety record, including the findings that shaped how the whole class is now used. It suits some people very well and is the wrong choice for others.
Calm, careful medication review by a consultant rheumatologist.
What this medicine is
Tofacitinib is a targeted synthetic DMARD, often called a JAK inhibitor. Janus kinases are enzymes inside cells that pass on messages from inflammatory signals arriving at the cell surface. By blocking several of those enzymes, tofacitinib interrupts a number of inflammatory pathways at once. It is taken by mouth, and both immediate-release and prolonged-release forms exist. The prescriber sets the strength, form and schedule, and the amount is reduced in kidney or liver impairment or with certain interacting medicines, so I do not publish dose schedules here.
Uses and context
Tofacitinib is used, where locally approved, in rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, ulcerative colitis and polyarticular juvenile idiopathic arthritis. Licensed and locally approved indications differ between countries and between the JAK inhibitors, so tofacitinib, upadacitinib and baricitinib are not interchangeable and I choose between them deliberately. It is generally considered when a conventional DMARD such as methotrexate has not given adequate control, or cannot be used.
How this relates to rheumatology care
Realistic benefit and timing: JAK inhibitors tend to work quickly. Many patients notice improvement within two to four weeks, with a clearer picture by about three months, and I review with examination and blood tests rather than impressions alone. It can be used with methotrexate or, unlike some biologics, on its own. My selection depends heavily on your risk profile. A large safety study in rheumatoid arthritis patients aged over fifty with a cardiovascular risk factor found more major cardiovascular events and more cancers with tofacitinib than with a TNF inhibitor, and the class has also been linked to blood clots and shingles. So in an older patient, a current or former long-term smoker, or someone with cardiovascular or cancer risk factors, another option is often the better choice, while in a younger patient without those risks a JAK inhibitor can be an excellent one. That balance is individual, and I will go through it with you. Related reading includes my guides to rheumatoid arthritis, psoriatic arthritis and ankylosing spondylitis.
What safety checks may matter
Full blood count before starting and during treatment, watching neutrophils, lymphocytes and haemoglobin
Liver function tests at baseline and on follow-up
Lipid profile at baseline and rechecked after starting, since cholesterol can rise
Kidney function, with the amount adjusted by the prescriber in impairment
Tuberculosis screening with chest X-ray and IGRA or Mantoux, plus hepatitis B and C screening before starting
Assessment of cardiovascular risk, clot risk, smoking history and cancer history before choosing this class
Vaccination review, with non-live vaccines and shingles vaccination considered before starting where available
Skin checks and age-appropriate cancer screening kept up to date
Side effects and red flags
If you have emergency symptoms such as severe allergic reaction, breathing difficulty, chest pain, stroke-like symptoms, severe abdominal pain, vomiting blood, black stools, sudden vision loss, severe infection symptoms, or severe weakness or confusion, please seek urgent medical care first rather than waiting for a WhatsApp reply.
Calf pain, swelling or tenderness in one leg, which can indicate a clot
Sudden breathlessness, chest pain or coughing blood, which can indicate a clot in the lung
Chest pain, pressure or tightness, or symptoms of stroke such as face droop, arm weakness or slurred speech
Fever, chills, a persistent cough, night sweats or any sign of serious infection
A painful blistering rash in a band, which may be shingles
Severe abdominal pain with fever, which needs urgent assessment
Facial or tongue swelling, or another sign of a severe allergic reaction
Things worth knowing day to day
Infection precautions: pause the tablets during a significant infection or fever and contact me. Shingles is more common with this class, so report any painful blistering rash promptly.
Avoid live vaccines while on tofacitinib. Non-live vaccines are encouraged, and shingles vaccination is best considered before starting.
Do not smoke. Smoking adds to both the cardiovascular and the clot risk that already need weighing with this class.
Tell me about any personal or family history of blood clots, heart attack, stroke or cancer, and about hormone treatments or long periods of immobility such as long-haul flights.
Tell any surgeon or dentist that you take tofacitinib. It is usually paused around major surgery and restarted once healing is secure and there is no infection.
Common effects include upper respiratory infections, headache, nausea, diarrhoea, raised cholesterol and mild blood count changes.
Tofacitinib is avoided in pregnancy and breastfeeding, and effective contraception is advised during treatment and for a period afterwards. If you are planning a family, tell me early so we can switch to a more suitable option in good time.
Do not start new medicines without checking, as some antifungals and antibiotics change tofacitinib levels.
Questions patients often ask me about this medicine
Speak with me
If tofacitinib has been suggested for you, or you would like an honest discussion of where a JAK inhibitor sits among your options, please message my clinic. Suitability is individual, and I will weigh it with you.
Other medications used in rheumatology care
This page is for general education only and does not replace medical advice. Please consult a qualified healthcare professional for diagnosis and treatment. Do not start, stop, or change any medicine without advice from your doctor.