Disclosed are phosphate-containing dimers of (5R)-3-[3-fluoro-4-[6-(2-methyl-2H-tetrazol-5-yl)-3-pyridinyl]phenyl]-5-(hydroxymethyl)-2-oxazolidinone, having antibiotic activity in vivo upon cleaving, wherein M is OR1 wherein R1 is H, or a pharmaceutically acceptable cation. Also disclosed are compositions comprising such compounds and also the use of such for treating or preventing an bacterial infection.