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.
Discuss with your doctor appropriate forms of birth control before starting treatment with fluorouracil topical. It is not known whether fluorouracil topical passes into breast milk. Do not use fluorouracil topical without first talking to your doctor if you are breast-feeding a baby.o not use other prescription or over-the-counter skin products without first talking to your doctor during treatment with fluorouracil topical. They may interfere with treatment or increase irritation to the skin. Drugs other than those listed here may also interact with fluorouracil topical.