I'll answer here. My wife took UFT, tegafur - uracil, every day for 8 years, along with a lot of other chemistry, hand fit for her with a lot of observation, blood and tissue work. Uracil is a mild competitive inhibitor for fluorouracil; UFT is a milder drug dosed as
daily immunochemo TID, as developed in Japan. Across the years, we modulated UFT's immunochemo inhibition properties with celecoxib, cimetidine, leucovorin, aspirin, menatetrenone, beta glucans and other immune modulating powders, flavonoids, IV vitamin C, various natural anti-inflammatories and essential nutrients, sometimes in large doses.
S-1 is tegafur with a pair of chemicals that are potent, irreversible inhibitors. In 2010-2011, I got the impression that S-1 is hard to finely dose and has more side effects, typically dosed with more immune damage for limited periods of treatment time. Oncologists may have gotten better at that over a dozen years since startup. I have not seen experience reported on how much S-1's effects might be modulated and ameliorated by careful metronomic dosing and nutraceutical treatments.
A lot of nutraceutical uses overlap between cancer and viral support but again no insight on S-1's special, irreversible inhibitors. With the other 5FU drugs, overlaps that I've seen or heard of include:
megadose vitamin D3 (with menaquinone-4 and magnesium), IV vitamin C (sometimes with slow release, oral potassium), zinc, quercetin, resveratrol, melatonin and beta glucans. Apparently CV19 depletes potassium as well as some of the controversial generic drugs with QTc elongation, so tests that don't control potassium and magnesium blood levels by monitoring, and repletion as necessary, are "wasteful" and less informative...
One might also suspect CV19's nasty microclot coagulation derangement to be partly associated with depleted ascorbate, zinc and flavonoids.
This doctor's
prophylatic regimin is much lower than a more nutraceutically oriented approach might, but is remarkable for a mainstream EBM approach.