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# Black Box Warning Added to Pfizer’s Xeljanz
- URL: https://www.fdaweb.com/black-box-warning-added-to-pfizers-xeljanz/
- Published: 2019-07-26T12:00:00.000Z
- Updated: 2026-09-15T01:40:25.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5144628

FDA has approved a Black Boxed warning about an increased risk of blood clots and death with Pfizer’s tofacitinib (Xeljanz, Xeljanz XR) 10 mg twice daily dose,which is used in patients with ulcerative colitis. In addition, tofacitinib’s use for ulcerative colitis will be limited to certain patients who are not treated effectively or who experience severe side effects with certain other medicines, an [agency update](https://www.fda.gov/drugs/drug-safety-and-availability/fda-approves-boxed-warning-about-increased-risk-blood-clots-and-death-higher-dose-arthritis-and?ref=fdaweb.com) says. In February, FDA issued a [safety alert](https://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/UCM632016?utm%5Fcampaign=FDA%20MedWatch%20Xeljanz%2C%20Xeljanz%20XR%20%28tofacitinib%29%3A%20Safety%20Communication&utm%5Fmedium=email&utm%5Fsource=Eloqua) warning about the blood clots after a safety clinical trial found increased risk when a 10 mg twice daily dose was used in patients with rheumatoid arthritis. “FDA has not approved this 10 mg twice daily dose for RA; this dose is only approved in the dosing regimen for patients with ulcerative colitis,” the alert said.