With cold and virus, is it okay to take antibiotics whilst on blood thinners ( xarelto, ) and detralex 500mg?

Blood thinners & Abx: First of all, you don't want to treat a virus (the usual cold) with an antibiotic, because antibiotics don't work against viruses, only against bacteria, which cause secondary problems will sinusitis or ear infections or bronchitis. For blood thinners generally, the manufacturer recommends caution with all antibiotics, but if you need one you should take one and just monitor your blood tests more.