Sunitinib belongs to a group of medicines called antineoplastic agents. Sunitinib 50 mg capsule is used to treat gastrointestinal stromal tumors and kidney cancer. It works by inhibiting the growth of cancer cells in the body which can be done by stopping the blood supply to the cancer cells which eventually causes the death of cancer cells. Some common side effects of Sunitinib 50 mg Capsule are fatigue, high blood pressure, abdominal pain, nausea, constipation, mouth sores, dry mouth, etc.