Lentris 4mg Capsule is an oral receptor tyrosine kinase inhibitor used in the treatment of thyroid cancer. Lentris 4mg Capsule can be taken with or without food, but try to have it at the same time every day to get the most benefits. Your doctor will decide what dose is necessary and how often you need to take it. This will depend on what you are being treated for and may change from time to time. You should take it exactly as your doctor has advised. Taking it in the wrong way or taking too much can cause very serious side effects. It may take several weeks or months for you to see or feel the benefits but do not stop taking it unless your doctor tells you to. The most common side effects of this medicine include tiredness, joint pain, muscle pain, nausea, and vomiting. It might also cause severe headache, confusion, problems with your eyesight, and difficult talking. If happens, your doctor may checked you for blood pressure as these might be symptom of high blood pressure. If you experience severe diarrhea, then consult with your doctor or drink plenty of fluids. Let your doctor know about severe abdominal pain or black, tarry, or bloody stools as it might be symptoms of bleeding disorder. You may be asked for some blood tests to check for liver, kidney, and level of thyroid stimulating hormones. Before taking it, tell your doctor if have heart disease, liver, or kidney problems or are taking any medicines to treat infections. Many other medicines can affect, or be affected by, this medicine so let your healthcare team know all medications you are using. This medicine is not recommended during pregnancy or while breastfeeding. Use of effective contraception by both males and females during treatment is important to avoid pregnancy.