cephalosporin ceftibuten CHEBI:554578 A third-generation cephalosporin antibiotic with a [(2<i>Z</i>)-2-(2-amino-1,3-thiazol-4-yl)-4-carboxybut-2-enoyl]amino substituent at the 7 position of the cephem skeleton. An orally-administered agent, ceftibuten is used as the dihydrate to treat urinary-tract and respiratory-tract infections. dicarboxylic acid