When a person becomes infected with a norovirus, the virus begins to multiply within the small intestine. After approximately 1 to 2 days, norovirus symptoms can begin. This period between the norovirus transmission and the start of symptoms is the  norovirus incubation period ..In some cases, the norovirus incubation period can be as short as 12 hours.his period between the norovirus transmission and the start of symptoms is the  norovirus incubation period .. In some cases, the norovirus incubation period can be as short as 12 hours.
Drug type: Fluorouracil is an anti-cancer (antineoplastic or cytotoxic) chemotherapy drug. Fluorouracil is classified as an antimetabolite.. (For more detail, see How Fluorouracil Works section below). What Fluorouracil Is Used For: 1  Colon and rectal cancer. 2  Breast cancer.
5- Fluorouracil (5-FU) has been the first-choice chemotherapy drug for colorectal cancer for many years. It is used in combination with leucovorin (a vitamin), which makes 5-FU more effective. 5-FU is given intravenously. A pill form of 5-FU, Xeloda, is used for colorectal cancer that has spread to other organs. Xeloda is also being used as adjuvant therapy or neoadjuvant therapy with radiation in patients with rectal cancers to heighten the effect of radiation. Other drugs include Camptosar and Eloxatin.