It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly. Blood tests may be needed to check for unwanted effects.
Using this medicine while you are pregnant can harm your unborn baby. Use an effective form of birth control to keep from getting pregnant. If you think you have become pregnant while using the medicine, tell your doctor right away.
Leflunomide may also cause birth defects if the father is using it when his sexual partner becomes pregnant. Men taking leflunomide should use condoms as a form of birth control during sexual intercourse. A man intending to father a child should stop taking this medicine and check with his doctor right away.
Serious skin reactions can occur with this medicine. Stop using this medicine and check with your doctor right away if you have any of the following symptoms while taking this medicine: blistering, peeling, or loosening of the skin; chills; itching; joint or muscle pain; red skin lesions, often with a purple center; sores, ulcers, or white spots in the mouth or on the lips; or unusual tiredness or weakness.
Liver problems may occur while you are using this medicine. Stop using this medicine and check with your doctor right away if you are having more than one of these symptoms: abdominal or stomach pain or tenderness; clay-colored stools; dark urine; decreased appetite; fever; headache; loss of appetite; nausea or vomiting; skin rash; swelling of the feet or lower legs; unusual tiredness or weakness; or yellow eyes or skin.
Leflunomide can temporarily lower the number of white blood cells in your blood, increasing the chance of getting an infection. It can also lower the number of platelets, which are necessary for proper blood clotting. If this occurs, there are certain precautions you can take, especially when your blood count is low, to reduce the risk of infection or bleeding:
- If you can, avoid people with infections. Check with your doctor immediately if you think you are getting an infection or if you get a fever or chills, cough or hoarseness, lower back or side pain, or painful or difficult urination.
- Check with your doctor immediately if you notice any unusual bleeding or bruising; black, tarry stools; blood in the urine or stools; or pinpoint red spots on your skin.
- Be careful when using a regular toothbrush, dental floss, or toothpick. Your medical doctor, dentist, or nurse may recommend other ways to clean your teeth and gums. Check with your medical doctor before having any dental work done.
- Do not touch your eyes or the inside of your nose unless you have just washed your hands and have not touched anything else in the meantime.
- Be careful not to cut yourself when you are using sharp objects such as a safety razor or fingernail or toenail cutters.
- Avoid contact sports or other situations where bruising or injury could occur.
Check with your doctor right away if you have a cough with or without a fever, shortness of breath, or any difficulty with breathing.
You will need to have a skin test for tuberculosis before you start using this medicine. Tell your doctor if you or anyone in your home has ever had a positive reaction to a tuberculosis test.
Using this medicine may increase your risk of getting serious infections or cancer. Talk to your doctor if you have concerns about this risk.
Stop using this medicine and check with your doctor right away if you are having burning, numbness, tingling, or painful sensations in the arms, hands, legs, or feet. These could be symptoms of a condition called peripheral neuropathy.
While you are being treated with leflunomide, and after you stop using it, do not have any immunizations (vaccinations) without your doctor's approval. Live virus vaccines should not be given while receiving this medicine.
You will need to have your blood pressure measured before starting this medicine and while you are using it. If you notice any change to your recommended blood pressure, call your doctor right away. If you have questions about this, talk to your doctor.
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.