An increase in cancers was not reported in clinical studies with leflunomide to date. Call your doctor if you have any unusual problems while taking this medication. You or your doctor can report a serious side effect to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online at http://www.fda.gov/Safety/MedWatch or by phone at 1-800-332-1088. If you experience any of the following symptoms or those listed in the IMPORTANT WARNING or SPECIAL PRECAUTIONS section, call your doctor immediately or get emergency medical treatment: diarrhea vomiting heartburn headache dizziness weight loss back pain muscle pain or weakness pain, burning, numbness, or tingling in the hands or feet hair loss leg cramps dry skin rash with or without a fever hives blisters or peeling of skin mouth sores itching difficulty breathing new or worsening cough chest pain pale skin Receiving medications which suppress the immune system may increase the risk of developing certain types of cancer. Other side effects of leflunomide are possible. Leflunomide could have unwanted effects. Leflunomide risks should be discussed with your doctor. Any of the following symptoms should be reported to your doctor if they are severe or persistent: diarrhoea, vomiting, heartburn, headache, weight loss, back pain, muscle pain or weakness, pain, burning, numbness, or tingling in the hands or feet, hair loss, leg cramps, dry skin rash with or without a fever, hives, blisters or peeling of the skin, itching difficulty breathing, new or worsening cough, chest pain, pale skin
Take with or without food. The absorption is unaffected by food.
Inquire with your doctor if drinking alcohol is safe for you to do while taking leflunomide. Without consulting your doctor, avoid getting any vaccinations. Leflunomide should not be taken if you have any of the following conditions: an allergy to leflunomide or any of its ingredients; are pregnant; or have liver disease. Leflunomide may exacerbate an existing tuberculosis (TB) infection and, if you don't already have any, may make your condition worse. Before you start taking leflunomide, your doctor will administer antibiotics to treat the infection if you do have TB. If you experience any of the following symptoms during your treatment with leflunomide, call your doctor: fever; sore throat; cough; flu-like symptoms; area of warm, red, swollen, or painful skin; painful, difficult, or frequent urination; or other signs of infection. Low blood cell counts and anemia may result from leflunomide. Rare cases of severe skin reactions have been reported. There have been reports of serious side effects. Leflunomide treatment has been associated with severe liver damage, including fatal liver failure. You run a higher risk of getting an infection if you take leflunomide. If you develop a skin rash while undergoing treatment, let your doctor know. Inform your doctor right away if you notice any symptoms of liver disease, such as: extreme fatigue, stomach pain, or yellowing of the skin or whites of the eyes (jaundice). Leflunomide may also raise blood pressure. Before starting treatment and on a regular basis going forward, have your blood pressure checked. If you have an infection, your leflunomide treatment may need to be stopped.