Gemcitabine is most commonly used to treat cancers of the lung and pacreas, but is also used to treat mesothelioma. Gemcitabine belongs to a group of medicines called antimetabolites. Gemcitabine is given intravenously.

Gemcitabine prevents cells from making DNA and RNA by interfering with the synthesis of nucleic acids. This stops the growth of cancer cells, causing the cells to die. However, Gemcitabine can sometimes also affect normal cells causing side effects. Possible side effects include: nausea, vomiting, damage to kidneys, fatigue, reduction of production of blood cells (1. lowers the patient's immunity and therefore increases the chances of infection and 2. reduces the number of platelets and decreases the blood's ability to clot), loss of appetite, change on liver and kidney function, swelling, rashes, flu-like illness, diarrhea and hair thinning.

Kidney and liver changes are usually undetected by the patient but are watched by doctors. Medications are prescribed for the rashes and diarrhea. Hair will grow back in fullness once the treatment is over.

Before starting Gemcitabine treatment patients should discuss its effects on fertility and their ability to conceive after treatment. Gemcitabine may cause birth defects so women should take birth control and avoid getting pregnant when taking the medication. Women should not breast feed while taking Gemcitabine as the medicine may travel through the milk to the baby. Also vaccinations should not be taken during treatment which causes patients to be immuno-compromised.