<prompt> Longest acting cephalosporin:CeftriaxoneCeftazidimeCefoperazoneCefotaxime  <response>: Ans: a Ceftriaxone Ref: Tripathi, 6th ed, p. 706 10th ed, p. 735- Ceftriaxone has a long duration of action with half life of 8 hrs- Ceftazidime has half life of 1.5-1.8 hrs- Cefaperazone has half life of 2 hrs- Cefotaxime has half life of 1 hrFirst-generation cephalosporinsThird- generation cephalosporinsCefadroxil POCefotaxime IVCephalexin PO Cephradine POCeftazidime IVCefazolin IVCeftriaxone IV Ceftizoxime IV Cefoperazone POSecond-generation cephalosporinsCefixime POCefoxitin IVCefpodoxime proxetil POCefotetan IVCefdinir POCefuroxime TVCeftamet pivoxil POCefuroxime axetil PO Fourth-generation cephalosporins Cefepime IV Cefpirome IVCephalosporins are not active against enterococci and L monocytogenes.Cefazolin penetrates well into most tissues. It is a drug of choice for surgical prophylaxisCeftriaxone and cefotaxime are the most active cephalosporins against penicillin-resistant strains of pneumococci and are recommended for empirical therapy of serious infections that may be caused by these strains.Cephalosporins that contain a methylthiotetrazole group e.g., cefamandole, cefmetazole, cefotetan, cefoperazone frequently cause hypoprothrombinemia and bleeding disorders 