Tofaxen

Indications

Tofacitinib is a specialist medicine used to treat moderate to severe rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis and ulcerative colitis, usually when other treatments such as Methotrexate or biologic injections have not worked well enough or are not suitable. The oral solution is used in some children with juvenile idiopathic arthritis.

How It Works

Tofacitinib blocks enzymes inside immune cells called Janus kinases (JAKs). These enzymes pass on signals that drive inflammation. Blocking them calms the overactive immune system, reducing joint pain, swelling and gut inflammation.

Dosage and Administration

• Rheumatoid and psoriatic arthritis, adults: usually 5 mg twice a day, or one 11 mg extended-release tablet once a day, as prescribed.
• Ulcerative colitis, ankylosing spondylitis and children: as prescribed by the specialist.
• People with kidney or liver problems, or taking certain other medicines, may need a lower dose.
• Take with or without food. Swallow extended-release tablets whole.

Interactions

• Ketoconazole and Fluconazole raise tofacitinib levels; the dose may need lowering.
• Rifampicin and other strong enzyme inducers can make it stop working.
• Do not combine with biologic medicines or strong immune-suppressing medicines such as Azathioprine or Ciclosporin.
• Avoid live vaccines during treatment; get vaccinations up to date before starting, as the doctor advises.

Contraindications

• Allergy to tofacitinib.
• Active serious infection, including active tuberculosis.
• Severe liver disease.
• Pregnancy and breastfeeding.
• Very low white blood cell, lymphocyte or haemoglobin levels.

Side Effects

Common: colds and sore throat, headache, diarrhoea, raised cholesterol, raised liver enzymes and shingles (painful blistering rash).

Get urgent medical help for: fever, chills, persistent cough or other signs of serious infection; chest pain or shortness of breath; pain, swelling or redness in a leg (possible blood clot); sudden weakness, numbness or trouble speaking; sudden severe stomach pain; yellow eyes or skin; or signs of an allergic reaction such as swelling of the face or difficulty breathing.

Pregnancy and Lactation

Do not use in pregnancy. Women who could become pregnant should use effective contraception during treatment and for at least 4 weeks after the last dose. Do not breastfeed during treatment, and ask the doctor how long to wait after stopping.

Precautions and Warnings

• Tests for tuberculosis and hepatitis B and C are needed before starting.
• It raises the risk of serious infections, blood clots, heart attack, stroke and some cancers, especially in people over 65, current or past smokers and people with heart disease risk factors. The doctor weighs these risks before prescribing.
• Regular blood tests check blood counts, liver function and cholesterol.
• Report any new skin lumps or changes.

Overdose

There is no specific antidote. Seek medical help straight away; the patient is watched for side effects and given supportive care.

Therapeutic Class

Janus kinase (JAK) inhibitor; immunosuppressant and disease-modifying anti-rheumatic drug (DMARD).

Storage

Store below 30°C in a dry place, in the original pack, away from light and out of the reach of children.