Gimeracil

Gimeracil is an adjunct to antineoplastic therapy, used to increase the concentration and effect of the main active componets within chemotherapy regimens. Approved by the European Medicines Agency (EMA) in March 2011, Gimeracil is available in combination with Oteracil and Tegafur within the commercially available product "Teysuno". The main active ingredient in Teysuno is Tegafur, a pro-drug of Fluorouracil (5-FU), which is a cytotoxic anti-metabolite drug that acts on rapidly dividing cancer cells. By mimicking a class of compounds called "pyrimidines" that are essential components of RNA and DNA, 5-FU is able to insert itself into strands of DNA and RNA, thereby halting the replication process necessary for continued cancer growth. Gimeracil's main role within Teysuno is to prevent the breakdown of Fluorouracil (5-FU), which helps to maintin high enough concentrations for sustained effect against cancer cells . It functions by reversibly and selectively blocking the enzyme dihydropyrimidine dehydrogenase (DPD), which is involved in the degradation of 5-FU . This allows higher concentrations of 5-FU to be achieved with a lower dose of tegafur, thereby also reducing toxic side effects.