Before you begin taking a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should take Tarceva (Erlotinib).

Corneal perforation: Rarely, Tarceva (Erlotinib) has been linked to corneal perforation, a severe injury to the part of the eye that focuses light into the eye. If you experience persistent eye pain or changes in vision, contact your doctor as soon as possible.

Dehydration: Severe dehydration can occur with the use of Tarceva (Erlotinib). This may be due to severe or persistent diarrhea, vomiting, or decreased fluid intake. Dehydration can lead to kidney failure, if it is severe enough. During treatment with Tarceva (Erlotinib), your may be encouraged to drink extra water. Your doctor will do blood tests to check the function of your kidneys.

Gastrointestinal perforation and bleeding: Tarceva (Erlotinib) can cause a number of problems in the digestive system. Gastrointestinal perforation is a serious and sometimes fatal condition in which a hole develops somewhere along the digestive system, resulting in inflammation of the abdomen. If you experience fever or chills with severe abdominal pain, nausea or vomiting, seek immediate medical attention.

Tarceva (Erlotinib) can also cause bleeding in the digestive system. This is also very serious and sometimes fatal. Get immediate medical attention if you experience signs of bleeding in the stomach or intestines, such as vomiting blood or material that looks like coffee grounds, or stools that are black and tarry.

Grapefruit juice: Grapefruit juice can interfere with how the liver removes Tarceva (Erlotinib) from the body, resulting in increased side effects. People should not drink grapefruit juice while taking Tarceva (Erlotinib).

Interstitial lung disease (ILD): This is a rare but serious complication. People with other lung conditions (e.g., inflammation of the lung) have an increased risk of death from ILD. If you develop symptoms of ILD such as shortness of breath with cough or fever, seek immediate medical attention.

Kidney function: If you have reduced kidney function, discuss with your doctor how Tarceva (Erlotinib) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Tarceva (Erlotinib), and whether any special monitoring is needed.

Liver function: Liver disease or reduced liver function may cause Tarceva (Erlotinib) to build up in the body, which may cause side effects. If you have reduced liver function or liver disease, discuss with your doctor how Tarceva (Erlotinib) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Tarceva (Erlotinib), and whether any special monitoring is needed.

Tarceva (Erlotinib) has been reported to cause liver failure, which can cause death. If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.

Skin reactions: Severe skin reactions have been linked to Tarceva (Erlotinib) use. Although rare, they are considered medical emergencies and require immediate medical attention.

If you experience skin blistering or peeling, a rash that covers a large area of the body, a rash that spreads quickly, or a rash combined with fever or discomfort, seek medical attention immediately.

Smoking: Smoking may cause your body to eliminate Tarceva (Erlotinib) more quickly. This results in less medication being available to treat the disease. If you smoke, speak to your doctor.

Warfarin: Tarceva (Erlotinib) may cause bleeding in people who take warfarin. If you are taking warfarin, discuss with your doctor what special monitoring is needed.

Pregnancy: There are no adequate studies of use of Tarceva (Erlotinib) by pregnant women. Tarceva (Erlotinib) should not be taken during pregnancy. If you are a woman who could become pregnant, use a reliable method of birth control (e.g., condoms, birth control pill) during treatment and for at least 2 weeks after treatment is finished. If you become pregnant while taking Tarceva (Erlotinib), contact your doctor immediately.

Breast-feeding: It is not known if Tarceva (Erlotinib) passes into breast milk. If you are a breast-feeding mother and are taking Tarceva (Erlotinib), it may affect your baby. Due to the potential for serious harm to a baby if they are exposed to Tarceva (Erlotinib), breast-feeding mothers should not use Tarceva (Erlotinib).

Children: The safety and effectiveness of Tarceva (Erlotinib) have not been established for children.