Common and Serious Side Effects of Ritlecitinib

Release date: 2026-05-18 17:53:08     Recommended: 21

Common and Serious Side Effects of Ritlecitinib

Like other medications, ritlecitinib may cause side effects, but not everyone experiences them. Serious side effects require your close attention: if you develop painful, blistering rash with or without fever, this may be a sign of shingles; if you develop an itchy rash, this may be urticaria. If any of these signs occur, contact your doctor immediately and seek medical attention. Common side effects (may affect up to 1 in 10 people) include nasal, throat, or airway infections, diarrhea, dizziness, acne, rash (not urticaria or shingles), folliculitis (inflamed, painful, or itchy hair follicles), and elevated creatine kinase levels in blood tests. Uncommon side effects (may affect up to 1 in 100 people) include low platelet count, low lymphocyte count, and elevated liver enzymes (ALT and AST) in blood tests.

Self-Recognition of Thrombotic Events, Neurological Symptoms, and Cancer Risk

In addition to infections, users of ritlecitinib need to be aware of potential vascular and neurological risks. If you have ever had a blood clot in your leg (manifested as unilateral leg pain, swelling, increased skin temperature) or a blood clot in your lung (manifested as sudden chest pain, difficulty breathing, coughing up blood), be sure to inform your doctor before starting treatment. If any of these symptoms occur during treatment, seek immediate medical attention. Similarly, if you have ever had a blood clot in an artery of the eye (causing sudden blurred vision, visual field defects, or even vision loss) or a blood clot in a heart artery (i.e., myocardial infarction, manifested as crushing chest pain radiating to the left arm or jaw), inform your doctor. Additionally, if you experience any unexplained neurological symptoms during ritlecitinib treatment, such as persistent headache, confusion, limb weakness or numbness, or seizures, contact your doctor immediately to rule out rare neurological adverse events. Regarding cancer risk, it is currently unknown whether ritlecitinib increases the incidence of malignant tumors. If you have a history of cancer (including lymphoma or other solid tumors), your doctor will assess individual risks and benefits, and may recommend regular full-body skin examinations during treatment to detect any abnormal growths early.

Precautions for Pregnancy, Breastfeeding, Contraception, and Fertility

If you are pregnant, think you may be pregnant, or are planning to become pregnant, do not use ritlecitinib because this medication may harm fetal development. If you become pregnant or think you may be pregnant during treatment, inform your doctor immediately. For women of childbearing potential, effective contraception must be used during ritlecitinib treatment and for at least one month after the last dose. Your doctor can advise you on suitable contraceptive methods. Breastfeeding is also prohibited during ritlecitinib treatment because it is unknown whether the drug passes into breast milk or could have adverse effects on the nursing infant. You and your doctor should decide together whether to stop breastfeeding or stop the medication. Regarding fertility, there is currently insufficient evidence that ritlecitinib reduces fertility in women of childbearing potential or in men who can father a child. However, if you have any concerns, consult your doctor.