Tofacitinib
Tofacitinib, sold under the brand Xeljanz among others, is a medication used to treat rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, polyarticular course juvenile idiopathic arthritis, and ulcerative colitis. It is a janus kinase (JAK) inhibitor, discovered and developed by the National Institutes of Health and Pfizer. Common side effects include diarrhea, headache, and high blood pressure. Serious side effects may include infections, cancer, and pulmonary embolism. In 2019, the safety committee of the European Medicines Agency began a review of tofacitinib and recommended that doctors temporarily not prescribe the 10 mg twice-daily dose to people at high risk for pulmonary embolism. The U.S. Food and Drug Administration (FDA) also released warnings about the risk of blood clots. An important side effect of Jakinibs is serious bacterial, mycobacterial, fungal and viral infections. In the phase III trials of tofacitinib among opportunistic infections, pulmonary tuberculosis (TB) was reported in 3 cases all of which were initially negative upon screening for TB. It was approved for medical use in the United States in November 2012. The extended release version was approved in February 2016. It is available as a generic medication. Medical uses Rheumatoid arthritis Tofacitinib citrate is approved for medical use in the United States with an indication "to treat adults with moderately to severely active rheumatoid arthritis who have had an inadequate response to, or who are intolerant of, methotrexate." In the European Union, in combination with methotrexate, tofacitinib citrate is indicated for the treatment of moderate to severe active rheumatoid arthritis (RA) in adults who have responded inadequately to, or who are intolerant to one or more disease-modifying antirheumatic drugs. It can be given as monotherapy in case of intolerance to methotrexate or when treatment with MTX is inappropriate. Ulcerative colitis In May 2018, the FDA approved tofacitinib citrate "for the treatment of adult patients in the U.S. with moderately to severely active ulcerative colitis." Tofacitinib citrate is the first oral JAK inhibitor approved for use in chronic ulcerative colitis. Adverse effects Tofacitinib was initially not approved by European regulatory agencies because of concerns over efficacy and safety, although by 2018, the European Commission had approved it. Animal studies with tofacitinib conducted prior to human trials showed some carcinogenesis, mutagenesis, and impairment of fertility. The most commonly reported adverse reactions during the first three months in controlled clinical trials (occurring in 2% or more of patients treated with tofacitinib citrate monotherapy or in combination with DMARDs) were upper respiratory tract infections, headache, diarrhea, and nasopharyngitis (the "common cold"). Tofacitinib is required by the FDA to have a boxed warning on its label about possible injury and death due to problems such as infections, lymphoma, and other malignancies, which can arise from use of this drug. Serious infections leading to hospitalization or death, including tuberculosis and bacterial, invasive fungal, viral, and other opportunistic infections, have occurred in patients receiving tofacitinib. Epstein Barr virus-associated post-transplant lymphoproliferative disorder has been observed at an increased rate in renal transplant patients treated with tofacitinib while