Gemcitabine injection is an anti-cancer medication used to treat cancer of the pancreas, ovaries, and lungs. It works by interfering with the growth of cancer cells and slowing their spread in the body. Gemcitabine injection is usually given as an intravenous (IV) infusion into a vein over 30 minutes. Side effects of gemcitabine injection may include nausea, vomiting, fatigue, and fever. It is important to speak to your doctor about all potential side effects before starting treatment.