Lanvis 40mg Tablet is a purine analog used in the treatment of blood cancer. It works by preventing and stopping the growth of cancer cells in the body. Lanvis 40mg Tablet should be taken on an empty stomach, 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 bone marrow failures, stomatitis (inflammation of the mouth), enlarged liver, increased bilirubin in the blood, increased liver enzymes, and increased uric acid level in urine. Regular blood tests are required to check your blood cells along with heart, liver, and blood uric acid levels. In some cases, it makes you sensitive towards sunlight, take caution while stepping out. Before taking it, tell your doctor if you 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 doctor 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.