(klor am' bue sil)Chlorambucil can cause a decrease in the number of blood cells in your bone marrow. Your doctor will order laboratory tests before, during, and after your treatment to see if your blood cells are affected by this drug. Keep all appointments with the laboratory. Chlorambucil may increase the risk that you will develop other cancers. Talk to your doctor about this risk. Chlorambucil may interfere with the normal menstrual cycle (period) in women and may stop sperm production in men. Chlorambucil may cause permanent infertility (difficulty becoming pregnant); however, you should not assume that you cannot get pregnant, or that you cannot get someone else pregnant. Women who are pregnant should tell their doctors before they begin taking this drug. You should not plan to have children while receiving chemotherapy or for a while after treatments. (Talk to your doctor for further details.) Use a reliable method of birth control to prevent pregnancy. If you become pregnant while taking chlorambucil, call your doctor immediately. Chlorambucil may harm the fetus.