Xeljanz (tofacitinib)

Xeljanz (Tofacitinib) is an engineered biologic medication that is approved for use against rheumatoid arthritis among people with moderately to severely active disease who aren’t helped by methotrexate. Methotrexate is the most commonly prescribed medicine against RA. It is known as a disease-modifying anti-rheumatic drug (DMARD).1

Xeljanz was approved relatively recently, and it is the only biologic medication that can be taken by mouth.2 It can be taken alone or with other non-biologic DMARDs, including methotrexate. Xeljanz is also used to treat psoriatic arthritis and ulcerative colitis.3

Xeljanz is not available in generic forms.

What are the ingredients in Xeljanz?

The active ingredient in Xeljanz is tofacitinib citrate.3

How does Xeljanz work?

Xeljanz functions in the body to block naturally occurring immune system components known as Janus kinases (JAKs). It is part of a class of medicines known as JAK inhibitors. JAKs are a group of enzymes that work within the immune system and other cells to transmit signals that influence basic cell functions, including promoting inflammation. By blocking JAKs in immune cells, Xeljanz can interfere with the overly active immune processes that cause joint damage, pain, and swelling in RA.3,4

What are the possible side effects of Xeljanz?

Common side effects with Xeljanz include:2,3,4

  • Infections
  • Upper respiratory tract infections, including colds and sinus problems
  • Headaches
  • Diarrhea

In some patients, Xeljanz can cause more harmful side effects. Patients who take Xeljanz are at increased risk for serious infections, including viral, bacterial, and fungal infections, reactivation of TB and hepatitis B and C, as well as certain cancers.

Other rare but serious side effects include intestinal perforations, low blood cell numbers, liver problems, kidney problems, and increased cholesterol.2,3,4

This is not an exhaustive list of all potential side effects of Xeljanz. For more information, consult your doctor or healthcare provider. If you notice any new or worsening side effects, contact your doctor or healthcare provider immediately.

Things to note about Xeljanz

Before taking Xeljanz, tell your doctor if you3,4:

  • Have a current infection or are prone to recurring infections, including open cuts
  • Have HIV, diabetes, lung disease, or a weakened immune system
  • Have or have had Hepatitis B or C
  • Have or have had TB or been near somebody with active TB
  • Live in areas of the US known for fungal infections, including the Ohio and Mississippi Valley and the southwest
  • Have or have had any type of cancer
  • Have or have had liver or kidney problems
  • Have or have had stomach problems, including ulcers and inflammation
  • Are scheduled to receive a vaccine
  • Are pregnant or plan to become pregnant or are breastfeeding

There is an increased risk for serious infections with Xeljanz. This is because Xeljanz can decrease the ability of the immune system to fight infections. Xeljanz should not be taken by a patient with an active infection and should be stopped until any infection is resolved. There is also a risk of reactivation of TB as well as hepatitis B and C viruses with Xeljalnz. In some patients, there is also an elevated risk of certain cancers.3,4

Patients should be tested for latent TB before starting Xeljanz and monitored carefully for active infection. In addition, you should get tested before starting the medication and during treatment to monitor blood cell levels, cholesterol, and liver and kidney functioning. Patients taking Xeljanz should not take live vaccines. It can also harm a developing fetus, so you should not take it if you are pregnant or planning to become pregnant.2,3,4

Tell your doctor about any medications or supplements you are taking while on Xeljanz, because it doesn’t mix well with certain medicines, especially other immunosuppressants.3

Dosing information

Xeljanz comes as a small 5 mg tablet that is taken twice per day by mouth. It is also available in an 11 mg coated tablet (Xeljanx XR) that can be taken once per day.3

Some people start to see improvements within a few weeks of starting Xeljanz, but the medication can take a few months before it takes full effect.2

Written by: Sara Finkelstein | Last reviewed: June 2018.
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