Uracil Unit Converter

Uracil is one of the four nucleobases in RNA and a normal product of pyrimidine metabolism. In clinical testing, plasma uracil serves as a biomarker for the activity of dihydropyrimidine dehydrogenase (DPD), the enzyme responsible for breaking down uracil in the body.

When DPD activity is reduced, uracil accumulates in the blood. Because DPD also breaks down approximately 80% of fluoropyrimidine chemotherapy drugs such as 5-fluorouracil and capecitabine, measuring plasma uracil predicts how well a patient can metabolize these medications.

Plasma uracil testing is primarily used as a pre-treatment safety screen before fluoropyrimidine chemotherapy. It is one of two recommended methods for DPD screening, alongside DPYD genotyping.

Uracil is produced throughout the body as a byproduct of normal RNA turnover and pyrimidine metabolism. It is primarily broken down by the enzyme DPD in the liver, which is the major site of pyrimidine catabolism.