Before Using This Medicine

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For gemcitabine, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to gemcitabine.

Pregnancy—Tell your doctor if you are pregnant. Studies in mice and rabbits have shown that gemcitabine causes birth defects and death of the fetus, as well as problems in the mother.

Be sure that you have discussed this with your doctor before starting treatment with this medicine. It is best to use birth control while you are receiving gemcitabine. Also, tell your doctor right away if you think you have become pregnant during treatment.

Breast-feeding—It is not known whether gemcitabine passes into breast milk. However, because this medicine may cause serious side effects, breast-feeding is generally not recommended while you are receiving it.

Children—There is no specific information comparing use of gemcitabine in children with use in other age groups.

Older adults—Gemcitabine has been tested in elderly patients and has not been shown to cause different side effects or problems in older people than it does in younger adults. However, seriously low blood counts tend to occur more often in elderly patients.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking gemcitabine, it is especially important that your health care professional know if you are taking any of the following:

• Amphotericin B by injection (e.g., Fungizone) or
• Antithyroid agents (medicine for overactive thyroid) or
• Azathioprine (e.g., Imuran) or
• Chloramphenicol (e.g., Chloromycetin) or
• Colchicine or
• Flucytosine (e.g., Ancobon) or
• Ganciclovir (e.g., Cytovene) or
• Interferon (e.g., Intron A, Roferon-A) or
• Plicamycin (e.g., Mithracin) or
• Zidovudine (e.g., AZT, Retrovir) or
• If you have ever been treated with radiation or other cancer medicines—The risk of developing seriously low blood counts may be increased. Also, gemcitabine can cause problems, sometimes serious, in areas treated by radiation

• Azathioprine (e.g., Imuran) or
• Chlorambucil (e.g., Leukeran) or
• Corticosteroids (cortisone-like medicine) or
• Cyclosporine (e.g., Sandimmune) or
• Mercaptopurine (e.g., Purinethol) or
• Muromonab-CD3 (monoclonal antibody) (e.g., Orthoclone OKT3) or
• Tacrolimus (e.g., Prograf)—There may be an increased risk of infection because gemcitabine decreases your body's ability to fight it

Other medical problems—The presence of other medical problems may affect the use of gemcitabine. Make sure you tell your doctor if you have any other medical problems, especially:

• Chickenpox (including recent exposure) or
• Herpes zoster (shingles)—Risk of severe disease spreading to other parts of the body

• Infection—Gemcitabine can decrease your body's ability to fight infection

• Kidney disease or
• Liver disease, severe—These conditions sometimes increase the effects of medicines by causing them to be removed from the body more slowly