XELJANZ: Uses, Dosage & Side Effects
A Janus kinase (JAK) inhibitor for the treatment of rheumatoid arthritis, psoriatic arthritis, and ankylosing spondylitis in adults
XELJANZ (tofacitinib) is a prescription Janus kinase (JAK) inhibitor used for the treatment of moderate to severe rheumatoid arthritis, active psoriatic arthritis, and ankylosing spondylitis in adults. It works by selectively inhibiting JAK1 and JAK3 enzymes, which are critical for transmitting inflammatory cytokine signals involved in joint inflammation and immune dysregulation. The 11 mg extended-release tablet is taken once daily and is bioequivalent to the 5 mg immediate-release formulation taken twice daily. XELJANZ has demonstrated significant improvements in joint pain, swelling, physical function, and disease activity scores in large randomized controlled trials. It carries important safety warnings regarding serious infections, malignancies, cardiovascular events, and thrombosis that require careful patient selection and ongoing monitoring.
Quick Facts: XELJANZ
Key Takeaways
- XELJANZ (tofacitinib) is a targeted synthetic disease-modifying antirheumatic drug (tsDMARD) that inhibits JAK1 and JAK3 enzymes, reducing inflammatory signaling in rheumatoid arthritis, psoriatic arthritis, and ankylosing spondylitis.
- The 11 mg extended-release tablet is taken once daily with or without food, providing the convenience of a single daily oral dose compared with twice-daily immediate-release formulations or injectable biologic therapies.
- XELJANZ carries important boxed warnings for serious infections (including tuberculosis and opportunistic infections), malignancies (including lymphoma), major adverse cardiovascular events (MACE), and thrombosis (blood clots in veins and lungs).
- Regular blood monitoring is essential: white blood cell counts, red blood cell counts, liver function, and cholesterol levels must be checked before starting treatment and at regular intervals during therapy.
- XELJANZ must not be used during pregnancy or breastfeeding, and women of childbearing potential must use effective contraception during treatment and for at least 4 weeks after the last dose.
What Is XELJANZ and What Is It Used For?
XELJANZ contains the active substance tofacitinib, a potent and selective inhibitor of the Janus kinase (JAK) family of enzymes. JAK enzymes are a group of intracellular tyrosine kinases—specifically JAK1, JAK2, JAK3, and TYK2—that play essential roles in transmitting signals from cell surface cytokine receptors to the cell nucleus. These signaling pathways regulate immune cell development, activation, and function, as well as the production of inflammatory mediators. By preferentially inhibiting JAK1 and JAK3, with lesser activity against JAK2, tofacitinib modulates the signaling of multiple pro-inflammatory cytokines including interleukins (IL-2, IL-4, IL-6, IL-7, IL-9, IL-15, IL-21) and interferons that are central to the pathogenesis of autoimmune and inflammatory joint diseases.
Unlike biologic disease-modifying antirheumatic drugs (bDMARDs) such as TNF inhibitors, IL-6 receptor blockers, or T-cell co-stimulation modulators, which target specific extracellular molecules or cell surface receptors, tofacitinib acts inside the cell. This intracellular mechanism of action allows tofacitinib to simultaneously modulate multiple cytokine pathways that converge on JAK-dependent signaling. The result is a broad dampening of inflammatory processes, leading to reduced joint inflammation, decreased synovial hypertrophy, and protection against progressive structural joint damage. Because tofacitinib is a small molecule rather than a large protein, it can be administered orally—a significant practical advantage over injectable biologic therapies.
Rheumatoid Arthritis
XELJANZ is indicated for the treatment of moderate to severe active rheumatoid arthritis (RA) in adult patients who have had an inadequate response to, or who are intolerant of, one or more disease-modifying antirheumatic drugs (DMARDs). Rheumatoid arthritis is a chronic systemic autoimmune disease primarily characterized by persistent inflammation of the synovial joints, leading to progressive cartilage and bone destruction, functional disability, and reduced quality of life. The condition affects approximately 0.5–1% of the adult population worldwide, with a higher prevalence in women.
XELJANZ is used in combination with methotrexate when methotrexate alone has not provided adequate disease control. It may also be used as monotherapy in patients who cannot tolerate methotrexate or for whom methotrexate treatment is inappropriate. In pivotal clinical trials (ORAL Start, ORAL Solo, ORAL Standard, ORAL Scan, ORAL Sync, and ORAL Step), tofacitinib demonstrated statistically significant improvements in ACR20, ACR50, and ACR70 response rates compared with placebo. Patients experienced meaningful reductions in tender and swollen joint counts, improvements in patient-reported outcomes including pain, physical function (HAQ-DI), and disease activity scores (DAS28), as well as inhibition of radiographic progression of structural joint damage.
Psoriatic Arthritis
XELJANZ is indicated for the treatment of active psoriatic arthritis (PsA) in adult patients who have had an inadequate response to, or who are intolerant of, a prior DMARD therapy. Psoriatic arthritis is a chronic inflammatory musculoskeletal disease that occurs in association with psoriasis, affecting an estimated 10–30% of people with psoriasis. The condition can cause inflammation and damage in the peripheral joints, spine, entheses (tendon and ligament insertion points), and skin and nails.
XELJANZ is used in combination with methotrexate for the treatment of active PsA. In clinical trials (OPAL Broaden and OPAL Beyond), tofacitinib demonstrated significant improvements in ACR20 response rates, physical function, enthesitis, and dactylitis compared with placebo. Patients also experienced improvements in skin manifestations of psoriasis, as measured by the Psoriasis Area and Severity Index (PASI). These benefits were observed in patients who had an inadequate response to conventional synthetic DMARDs as well as those who had failed TNF inhibitor therapy.
Ankylosing Spondylitis
XELJANZ is indicated for the treatment of active ankylosing spondylitis (AS) in adult patients who have had an inadequate response to conventional therapy. Ankylosing spondylitis is a chronic inflammatory disease primarily affecting the axial skeleton, including the sacroiliac joints and spine. It is characterized by inflammatory back pain, spinal stiffness, and, in advanced cases, progressive spinal fusion leading to significant functional limitation. AS affects approximately 0.1–0.5% of the population worldwide, with onset typically in early adulthood.
In patients with active AS who have had an inadequate response to at least two non-steroidal anti-inflammatory drugs (NSAIDs), XELJANZ has shown significant improvements in the Assessment of SpondyloArthritis International Society (ASAS) 20 response, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), and Ankylosing Spondylitis Disease Activity Score (ASDAS). If XELJANZ has not demonstrated a clinical response within 16 weeks, your doctor may decide to discontinue treatment.
XELJANZ is a targeted synthetic DMARD (tsDMARD), meaning it is a small molecule that can be taken orally, unlike biologic DMARDs (bDMARDs) that require injection or infusion. While biologics target specific extracellular proteins (such as TNF-alpha, IL-6, or CD80/CD86), tofacitinib works inside the cell by blocking JAK enzymes. This offers patients a convenient once-daily oral alternative to injectable therapies, though the safety profile differs, particularly regarding infection risk, cardiovascular events, and malignancies.
What Should You Know Before Taking XELJANZ?
Contraindications
XELJANZ must not be used in the following situations:
- Hypersensitivity: If you are allergic to tofacitinib or any of the other ingredients in XELJANZ (see the Contents section below for a full list of excipients).
- Severe active infection: If you have a serious infection such as bloodstream infection (sepsis) or active tuberculosis. XELJANZ suppresses immune function and can worsen existing infections or increase the risk of new, potentially life-threatening infections.
- Severe hepatic impairment: If you have severe liver disease, including liver cirrhosis, as tofacitinib is substantially metabolized by the liver and may accumulate to dangerous levels.
- Pregnancy and breastfeeding: XELJANZ must not be used during pregnancy or while breastfeeding (see Pregnancy and Breastfeeding section below).
Warnings and Precautions
XELJANZ carries regulatory boxed warnings for serious infections, malignancies, major adverse cardiovascular events (MACE), and thrombosis. A large post-marketing safety study (ORAL Surveillance) in RA patients aged 50 and older with at least one cardiovascular risk factor showed increased risks of serious infections, malignancies, MACE, and venous thromboembolism with tofacitinib compared with TNF inhibitors. Your doctor will carefully evaluate whether XELJANZ is appropriate for you.
Talk to your doctor or pharmacist before taking XELJANZ if any of the following apply to you:
- Active or chronic infections: If you have any current infection, are being treated for an infection, or have recurrent infections. Tell your doctor immediately if you develop symptoms such as fever, chills, muscle aches, cough, shortness of breath, weight loss, warm or painful skin lesions, difficulty swallowing, diarrhea, stomach pain, burning sensation during urination, or excessive tiredness. XELJANZ can impair your body’s ability to fight infections and can worsen existing infections or increase susceptibility to new ones, including serious and potentially fatal infections such as tuberculosis, invasive fungal infections, bacterial sepsis, and viral reactivation.
- Tuberculosis (TB): If you have, or have previously had, tuberculosis, or have been in close contact with someone with TB. Your doctor will test you for TB before starting XELJANZ and may repeat the test during treatment. Active TB has occurred in patients receiving tofacitinib.
- Hepatitis B or C: If you have or have had hepatitis B or C virus infection. The virus can become reactivated during XELJANZ treatment. Your doctor may perform blood tests for hepatitis before and during treatment.
- Cancer history: If you are 65 years or older, have ever had any type of cancer, or are a current or former smoker. XELJANZ may increase the risk of certain cancers, including lymphoma, lung cancer, breast cancer, skin cancer (non-melanom), prostate cancer, and pancreatic cancer. Your doctor will consider whether XELJANZ is appropriate for you.
- Cardiovascular risk: If you have heart problems, high blood pressure, high cholesterol, diabetes, or are a current or former smoker. Patients treated with XELJANZ have experienced heart attacks and other major adverse cardiovascular events. Your doctor will evaluate your cardiovascular risk before starting treatment.
- Blood clot risk: If you have a history of blood clots in the lungs or veins, are severely overweight, have cancer or diabetes, have had a heart attack within the past 3 months, have recently undergone major surgery, use hormonal contraceptives or hormone replacement therapy, or have a blood clotting disorder (personal or family history). Blood clots in the lungs (pulmonary embolism) and veins (deep vein thrombosis) have been reported with XELJANZ, including fatal cases.
- Chronic lung disease: If you have any pre-existing lung condition, as interstitial lung disease has been reported.
- Fracture risk: If you are 65 or older, female, or taking corticosteroids (such as prednisone), as fractures have been reported more frequently in these patients.
- Diverticulitis: If you have had diverticulitis (inflammation of pouches in the bowel wall) or stomach/intestinal ulcers, as gastrointestinal perforations have occurred, particularly in patients also taking NSAIDs or corticosteroids.
- Kidney problems: Dose adjustment may be necessary in patients with renal impairment.
- Vaccinations: Certain live vaccines should not be given during XELJANZ treatment. Ensure you are up to date with all recommended vaccinations, including herpes zoster (shingles) vaccination, before starting therapy.
- Gastrointestinal narrowing: If you have narrowing of the gastrointestinal tract, inform your doctor, as rare cases of bowel obstruction have been reported with extended-release tablets similar to XELJANZ.
Contact your doctor or go to the emergency department immediately if you experience: sudden shortness of breath or difficulty breathing; chest pain or upper back pain; swelling of a leg or arm; leg pain or tenderness; redness or discoloration of a leg or arm; sudden severe headache with nausea, vomiting, or fainting; vision changes (blurry or partial vision loss); signs of a heart attack (severe chest pressure, shortness of breath, cold sweats, dizziness).
Required Monitoring Tests
Your doctor will perform blood tests before you start XELJANZ, after 4 to 8 weeks of treatment, and then every 3 months to monitor for potential complications. These tests include:
- White blood cell counts: Neutrophils and lymphocytes must be checked, as XELJANZ can reduce these infection-fighting cells. Treatment should not be started if counts are too low and may be paused if they decrease significantly during therapy.
- Red blood cell counts: To monitor for anemia, which can occur during treatment.
- Cholesterol levels: Checked at 8 weeks after starting, as tofacitinib can increase total cholesterol, LDL cholesterol, and HDL cholesterol levels.
- Liver function tests: Performed at regular intervals throughout treatment.
- Skin examinations: Recommended regularly due to the increased risk of non-melanoma skin cancer.
Elderly Patients
Patients aged 65 and older are at increased risk of infections (including serious infections), heart attack, certain cancers, and blood clots when taking XELJANZ. The ORAL Surveillance study demonstrated that these risks are particularly elevated in older patients with cardiovascular risk factors. Your doctor will carefully assess whether XELJANZ is appropriate for you and may consider alternative treatments. Close monitoring is essential throughout therapy.
Patients of Asian Descent
Patients of Japanese or Korean descent have a higher incidence of herpes zoster (shingles) during XELJANZ treatment. Inform your doctor if you develop painful blisters on the skin. The risk of certain lung problems may also be higher in patients of Asian descent.
Children and Adolescents
XELJANZ is not recommended for children and adolescents under 18 years of age. The safety and efficacy of tofacitinib have not been established in the pediatric population for the approved indications.
Pregnancy and Breastfeeding
XELJANZ must not be used during pregnancy. If you are a woman of childbearing potential, you must use effective contraception during treatment and for at least 4 weeks after the last dose. If you become pregnant while taking XELJANZ, stop taking it and inform your doctor immediately. Animal studies have shown adverse effects on fetal development, and the potential risk to a human fetus is not fully characterized.
XELJANZ must not be used while breastfeeding. It is not known whether tofacitinib passes into human breast milk, but given the mechanism of action and the potential for serious adverse effects in a nursing infant, breastfeeding must be discontinued before starting treatment. Discuss the timing of resuming breastfeeding after stopping XELJANZ with your doctor.
Driving and Operating Machinery
XELJANZ has no or negligible effect on the ability to drive or use machines. However, if you experience any side effects that could impair your alertness or coordination, you should refrain from driving or operating machinery until you feel well.
Important Information About Ingredients
XELJANZ 11 mg extended-release tablets contain approximately 152 mg of sorbitol (E420) per tablet. If you have been told by your doctor that you have an intolerance to some sugars, contact your doctor before taking this medicine. Sorbitol is a source of fructose, and patients with hereditary fructose intolerance should not take XELJANZ extended-release tablets.
How Does XELJANZ Interact with Other Drugs?
Unlike monoclonal antibody therapies that are degraded through general protein catabolism, tofacitinib is a small molecule drug that is primarily metabolized by hepatic cytochrome P450 (CYP) enzymes, specifically CYP3A4 with a minor contribution from CYP2C19. This means that XELJANZ has the potential for pharmacokinetic drug interactions with other medications that inhibit or induce these enzymes. Understanding these interactions is critical for safe and effective use of XELJANZ.
Additionally, there are important pharmacodynamic interactions to consider, particularly with other immunosuppressive agents. The combined use of XELJANZ with biologic DMARDs or potent immunosuppressants is not recommended due to the risk of additive immunosuppression and increased susceptibility to infections.
| Interacting Drug | Effect | Clinical Action |
|---|---|---|
| Ketoconazole (strong CYP3A4 inhibitor) | Increases tofacitinib exposure significantly | Dose reduction may be required; consult your doctor |
| Fluconazole (moderate CYP3A4/CYP2C19 inhibitor) | Increases tofacitinib exposure moderately | Dose reduction may be required; consult your doctor |
| Rifampicin (strong CYP3A4 inducer) | Decreases tofacitinib levels, reducing efficacy | Co-administration not recommended |
| Biologic DMARDs (TNF inhibitors, IL-17, IL-12/23, anti-integrins) | Additive immunosuppression, increased infection risk | Not recommended in combination with XELJANZ |
| Azathioprine, mercaptopurine, ciclosporin, tacrolimus | Additive immunosuppression | Not recommended in combination with XELJANZ |
| Methotrexate | No significant pharmacokinetic interaction | Can be used in combination (recommended for RA and PsA) |
| Corticosteroids (e.g., prednisone) | Increased infection and fracture risk | Use lowest effective dose; monitor closely |
If you have diabetes or are taking antidiabetic medications, inform your doctor. Tofacitinib may affect blood sugar levels, and your diabetes medication dose may need to be adjusted during XELJANZ treatment.
Always inform your doctor, pharmacist, or nurse about all medications you are currently taking, have recently taken, or plan to take. This includes prescription medicines, over-the-counter products, vitamins, and herbal supplements. Your doctor will determine whether any dose adjustments are necessary and will monitor you for potential interactions throughout your treatment.
Do not receive live or live-attenuated vaccines during XELJANZ treatment. Ensure that all recommended vaccinations, including shingles (herpes zoster) vaccination, are up to date before starting XELJANZ. Discuss your vaccination status with your doctor before beginning therapy.
What Is the Correct Dosage of XELJANZ?
XELJANZ should always be taken exactly as your doctor has prescribed. The dose must not be exceeded without medical guidance. XELJANZ is prescribed and supervised by a specialist physician experienced in the diagnosis and treatment of the condition for which it is being used. If you are unsure about your dose, consult your doctor or pharmacist.
Adults
| Indication | Dose | Frequency | Notes |
|---|---|---|---|
| Rheumatoid Arthritis | 11 mg | Once daily | With or without methotrexate |
| Psoriatic Arthritis | 11 mg | Once daily | In combination with methotrexate |
| Ankylosing Spondylitis | 11 mg | Once daily | Evaluate response at 16 weeks |
Try to take the extended-release tablet at the same time each day, either in the morning or evening, to maintain consistent drug levels. XELJANZ 11 mg extended-release tablets must be swallowed whole to ensure the full dose is released correctly over the 24-hour period. The tablets must not be crushed, split, or chewed. You may take XELJANZ with or without food.
Patients with rheumatoid arthritis, psoriatic arthritis, or ankylosing spondylitis may, in consultation with their doctor, switch between XELJANZ 5 mg film-coated tablets taken twice daily and XELJANZ 11 mg extended-release tablets taken once daily. The switch can be made the day after the last dose of either formulation. Do not switch between formulations without your doctor’s guidance.
When taking XELJANZ 11 mg extended-release tablets, you may notice something in your stool that looks like a tablet. This is the empty shell of the extended-release tablet after the medication has been absorbed by your body. This is expected and is not a cause for concern—the active medication has already been released and absorbed.
Dose Adjustments
Your doctor may reduce your dose of XELJANZ if you have:
- Liver problems: Patients with moderate hepatic impairment may require a lower dose. XELJANZ is contraindicated in severe hepatic impairment.
- Kidney problems: Patients with moderate to severe renal impairment may require dose adjustment.
- Concomitant CYP3A4 or CYP2C19 inhibitors: If you are taking strong CYP3A4 inhibitors (e.g., ketoconazole) or moderate CYP3A4/CYP2C19 dual inhibitors (e.g., fluconazole), your doctor will adjust your dose.
- Low blood cell counts: Treatment may be temporarily interrupted or permanently discontinued if blood tests show unacceptably low levels of neutrophils, lymphocytes, or hemoglobin.
Children and Adolescents
XELJANZ is not recommended for patients under 18 years of age. The safety and efficacy of tofacitinib have not been established in this population for rheumatoid arthritis, psoriatic arthritis, or ankylosing spondylitis.
Missed Dose
If you miss a dose, do not take a double dose to make up for it. Simply take your next 11 mg extended-release tablet at the usual time and continue as before. Using a daily reminder or associating the dose with a consistent daily activity can help prevent missed doses.
Overdose
If you have taken more extended-release tablets than prescribed, contact your doctor or pharmacist immediately. Symptoms of overdose may include increased risk of side effects, particularly infections and blood cell count changes. There is no specific antidote for tofacitinib overdose. Treatment is supportive, with monitoring of vital signs, blood counts, and clinical status. Given the extended-release formulation, monitoring may need to continue for an extended period.
Stopping Treatment
Do not stop taking XELJANZ without first consulting your doctor. If you stop treatment, your symptoms of rheumatoid arthritis, psoriatic arthritis, or ankylosing spondylitis may return and worsen. Your doctor will advise you on whether and when to discontinue treatment, and may recommend alternative therapies.
What Are the Side Effects of XELJANZ?
Like all medicines, XELJANZ can cause side effects, although not everyone will experience them. Some side effects can be serious and require immediate medical attention. In rare cases, infections may be life-threatening. Lung cancer, lymphoma (cancer of white blood cells), and heart attack have also been reported in patients taking XELJANZ.
If you notice any of the serious side effects listed below, contact your doctor immediately or seek emergency medical care.
Seek immediate medical attention if you develop: fever and chills, persistent cough, blistered skin, stomach pain, persistent headache, painful or burning urination, or excessive tiredness. These may indicate a serious infection requiring urgent treatment.
Common
May affect up to 1 in 10 people
- Pneumonia and bronchitis (lung infections)
- Herpes zoster (shingles)
- Nasopharyngitis (inflammation of nose and throat)
- Influenza (flu)
- Sinusitis (sinus infection)
- Cystitis (urinary tract infection)
- Pharyngitis (sore throat)
- Elevated muscle enzymes in the blood
- Stomach pain, nausea, vomiting, diarrhea, indigestion
- Low white blood cell count (neutropenia, lymphopenia)
- Anemia (low red blood cells)
- Swelling of hands and feet (peripheral edema)
- Headache
- High blood pressure (hypertension)
- Cough
- Skin rash, acne
Uncommon
May affect up to 1 in 100 people
- Lung cancer
- Tuberculosis
- Kidney infection
- Skin infections, herpes simplex (cold sores)
- Elevated blood creatinine (kidney function marker)
- Elevated cholesterol (including LDL)
- Fever, fatigue, weight gain, dehydration
- Muscle strain, tendinitis, joint swelling
- Abnormal sensations, insomnia
- Shortness of breath, skin redness, itching
- Fatty liver, diverticulitis
- Viral infections, including gastrointestinal
- Non-melanoma skin cancer
- Venous thromboembolism (blood clots in veins or lungs)
- Heart attack (myocardial infarction)
- Stomach or intestinal perforation
Rare
May affect up to 1 in 1,000 people
- Sepsis (bloodstream infection)
- Lymphoma (cancer of white blood cells)
- Disseminated tuberculosis (spreading to bones and other organs)
- Other unusual infections
- Joint infections
- Elevated liver enzymes (signs of liver problems)
- Muscle and joint pain
Very Rare
May affect up to 1 in 10,000 people
- Tuberculosis of the brain and spinal cord, meningitis
- Soft tissue and fascia infections (necrotizing fasciitis)
- Progressive multifocal leukoencephalopathy (PML) – a rare and serious brain infection
Overall, fewer side effects were observed when XELJANZ was used as monotherapy compared with use in combination with methotrexate for rheumatoid arthritis. This is consistent with the additive immunosuppressive effects of combination therapy.
Contact your doctor or emergency services immediately if you experience: signs of blood clots (sudden breathing difficulty, chest pain, leg swelling or pain, vision changes, severe headache with fainting or weakness on one side); signs of a heart attack (severe chest pressure spreading to arms, jaw, or back, shortness of breath, cold sweats, sudden dizziness); signs of severe infection (high fever, chills, persistent cough); new neurological symptoms (muscle weakness, vision changes, confusion, personality changes) as these may indicate PML.
If you experience any side effects, even if not listed above, talk to your doctor, pharmacist, or nurse. Reporting side effects helps continuously monitor the benefit-risk balance of medicines.
How Should You Store XELJANZ?
Proper storage of XELJANZ is important to maintain the quality and effectiveness of the medication. Follow these guidelines:
- Keep out of reach of children: Store XELJANZ in a safe location that children cannot access.
- Temperature: No special temperature storage requirements. Store at room temperature.
- Moisture protection: Keep the tablets in their original packaging (blister or bottle) to protect from moisture. Bottles contain silica gel desiccant to absorb moisture—leave this in the bottle.
- Expiration date: Do not use XELJANZ after the expiration date printed on the blister, bottle, or carton. The expiration date refers to the last day of the stated month.
- Visual inspection: Do not use this medicine if the tablets show visible signs of deterioration, such as being broken or discolored.
- Disposal: Do not dispose of XELJANZ in wastewater or household waste. Ask your pharmacist how to dispose of medicines you no longer use, to help protect the environment.
XELJANZ 11 mg extended-release tablets are available in blister packs containing 7 tablets each, with each carton containing 28 or 91 tablets. They are also available in bottles with silica gel desiccant containing 30 or 90 tablets. Not all pack sizes may be marketed in all countries.
What Does XELJANZ Contain?
Active Ingredient
The active substance is tofacitinib. Each extended-release tablet contains 11 mg of tofacitinib (administered as tofacitinib citrate, the citrate salt form). Tofacitinib is a small molecule Janus kinase inhibitor with the molecular formula C16H20N6O (free base).
Inactive Ingredients (Excipients)
| Ingredient | Role | Notes |
|---|---|---|
| Tofacitinib citrate | Active substance (JAK inhibitor) | 11 mg tofacitinib per tablet |
| Sorbitol (E420) | Osmotic agent / filler | ~152 mg per tablet; see excipient warning |
| Hydroxyethyl cellulose | Matrix former | Controls drug release rate |
| Copovidone | Binder | Tablet integrity |
| Magnesium stearate | Lubricant | Manufacturing aid |
| Cellulose acetate | Coating / release control membrane | Extended-release shell |
| Hydroxypropyl cellulose (E463) | Film coating component | Tablet coating |
| Hypromellose (E464) | Film coating component | Tablet coating |
| Titanium dioxide (E171) | Colorant / opacifier | White coating component |
| Triacetin | Plasticizer | Coating flexibility |
| Red iron oxide (E172) | Colorant | Pink tablet color |
The printing ink on the tablet contains shellac (E904), ammonium hydroxide (E527), propylene glycol (E1520), and black iron oxide (E172).
Appearance
XELJANZ 11 mg extended-release tablets are pink, oval-shaped tablets with markings for identification. The tablets are designed with an osmotic-controlled extended-release mechanism that slowly releases tofacitinib over approximately 24 hours as the tablet passes through the gastrointestinal tract.
Marketing Authorization Holder and Manufacturer
XELJANZ is manufactured by Pfizer Manufacturing Deutschland GmbH (Freiburg im Breisgau, Germany) and marketed globally by Pfizer. The marketing authorization holder for the European Economic Area is Pfizer Europe MA EEIG (Brussels, Belgium). XELJANZ is approved and available in numerous countries worldwide for the treatment of inflammatory joint diseases.
Frequently Asked Questions About XELJANZ
XELJANZ (tofacitinib) is a prescription JAK inhibitor used to treat three inflammatory joint conditions in adults: moderate to severe rheumatoid arthritis (when methotrexate alone has not worked well enough), active psoriatic arthritis (in combination with methotrexate, when prior treatment was insufficient), and ankylosing spondylitis (when conventional therapies have not provided adequate relief). It works by blocking Janus kinase enzymes inside immune cells, reducing the inflammatory processes that cause joint pain, swelling, and damage.
XELJANZ is a targeted synthetic DMARD (tsDMARD), which means it is a small molecule that can be taken as an oral tablet, unlike biologic DMARDs (such as adalimumab, etanercept, or infliximab) that require injection or infusion. While biologics target specific extracellular proteins like TNF-alpha, XELJANZ works inside the cell by inhibiting JAK enzymes. This gives patients the convenience of a once-daily pill rather than regular injections. However, the safety profiles differ: XELJANZ carries specific warnings about infections, blood clots, cardiovascular events, and certain cancers that your doctor will discuss with you.
Regular blood monitoring is essential during XELJANZ treatment. Your doctor will check your white blood cell counts (neutrophils and lymphocytes) and red blood cell counts (hemoglobin) before starting treatment, after 4 to 8 weeks, and then every 3 months. Cholesterol levels are checked at 8 weeks after starting. Liver function tests are performed at regular intervals. Your doctor may also test for tuberculosis and hepatitis before and during treatment. These tests help detect potential complications early so your doctor can adjust your treatment if needed.
No, XELJANZ 11 mg extended-release tablets must be swallowed whole. Do not crush, split, or chew them. The tablet is specially designed with an osmotic-controlled release mechanism that slowly releases the medication over 24 hours. Crushing or splitting the tablet would destroy this mechanism and cause the entire dose to be released at once, potentially leading to increased side effects. If you have difficulty swallowing tablets, discuss alternative formulations (such as the 5 mg immediate-release tablets taken twice daily) with your doctor.
This is completely normal and expected. What you see is the empty shell of the extended-release tablet. The XELJANZ 11 mg tablet uses an osmotic-controlled release system: water enters the tablet through a semi-permeable membrane, dissolving the tofacitinib inside and pushing it out through a small hole over approximately 24 hours. After the medication has been fully released and absorbed by your body, the insoluble outer shell passes through your digestive system and appears in your stool. This does not mean the medication was not absorbed—the active drug has already been delivered to your body.
Patients aged 65 and older may be at increased risk for several serious side effects while taking XELJANZ, including infections (some of which may be severe or fatal), heart attack, certain types of cancer, and blood clots. The ORAL Surveillance post-marketing study showed that these risks were particularly relevant in older patients with cardiovascular risk factors. Your doctor will carefully evaluate your individual risk profile—including smoking history, cardiovascular health, cancer history, and overall health status—before deciding whether XELJANZ is appropriate. Alternative treatments may be recommended if the risks outweigh the benefits.
References
- European Medicines Agency (EMA). XELJANZ (tofacitinib) – Summary of Product Characteristics. Last updated 2025. Available at: EMA XELJANZ EPAR.
- U.S. Food and Drug Administration (FDA). XELJANZ/XELJANZ XR (tofacitinib) – Prescribing Information. Pfizer Inc. Revised 2024.
- Ytterberg SR, Bhatt DL, Mikuls TR, et al. Cardiovascular and Cancer Risk with Tofacitinib in Rheumatoid Arthritis. N Engl J Med. 2022;386(4):316–326. doi:10.1056/NEJMoa2109927.
- Fleischmann R, Kremer J, Cush J, et al. Placebo-Controlled Trial of Tofacitinib Monotherapy in Rheumatoid Arthritis. N Engl J Med. 2012;367(6):495–507. doi:10.1056/NEJMoa1109071.
- Fraenkel L, Bathon JM, England BR, et al. 2021 American College of Rheumatology Guideline for the Treatment of Rheumatoid Arthritis. Arthritis Care Res. 2021;73(7):924–939. doi:10.1002/acr.24596.
- Smolen JS, Landewé RBM, Bergstra SA, et al. EULAR Recommendations for the Management of Rheumatoid Arthritis with Synthetic and Biological Disease-Modifying Antirheumatic Drugs: 2022 Update. Ann Rheum Dis. 2023;82(1):3–18. doi:10.1136/ard-2022-223356.
- Gladman D, Rigby W, Azevedo VF, et al. Tofacitinib for Psoriatic Arthritis in Patients with an Inadequate Response to TNF Inhibitors. N Engl J Med. 2017;377(16):1525–1536. doi:10.1056/NEJMoa1615977.
- Deodhar A, Sliwinska-Stanczyk P, Engelman M, et al. Tofacitinib for the Treatment of Ankylosing Spondylitis: A Phase III Randomised, Double-Blind, Placebo-Controlled Study. Ann Rheum Dis. 2021;80(8):1004–1013. doi:10.1136/annrheumdis-2020-219601.
- World Health Organization (WHO). Musculoskeletal Conditions. Fact Sheet. 2023. Available at: WHO Musculoskeletal Conditions.
- British National Formulary (BNF). Tofacitinib. National Institute for Health and Care Excellence (NICE). 2025.
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Specialists in rheumatology, immunology, and clinical pharmacology with extensive experience in inflammatory joint disease management and targeted synthetic DMARD therapies.
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Independent panel of board-certified physicians who verify all medical claims against current evidence and international guidelines (WHO, EMA, FDA, ACR, EULAR).
Editorial Standards
All content follows the GRADE evidence framework and is based on Level 1A evidence from systematic reviews and randomized controlled trials where available.
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