5-fluorouracil 1 Antimetabolites, Antineoplastic 1 Colorectal Neoplasms 1 Dihydrouracil Dehydrogenase (NADP) 1 Drug-Related Side Effects and Adverse Reactions 1 Fluorouracil 1 Genotype 1 Humans 1 Polymorphism, Genetic 1 adult 1 adverse effect aged 1 anemia 1 article 1 cancer chemotherapy 1 chemotherapy induced emesis 1 clinical article 1 colorectal cancer 1 coughing 1 denaturing high performance liquid chromatography 1 diarrhea 1 dihydropyrimidine dehydrogenase 1 drug blood level 1 drug fever 1 enzyme activity 1 female 1 fluorouracil 1 gastrointestinal toxicity 1 genetic polymorphism 1 genetic variability 1