Cephalosporins Flashcards
Cephalosporins
Beta-lactams structurally related to penicillins, 6-Membered dihydrothiazine ring in place of 5-Membered thiazolidine ring, Modification at 7-position alter antibacterial activity but at 3-alter pharmacokinetics, Bactericidal, Similar to penicillins, Classified by generations
Cefazolin
Ancef
First (Narrow Spectrum)
Injection
Streptococci (except penicillin resistant strains), S. aureus (except MRSA)
RECOMMENDED BY AHA for premed prophylaxis in penicillin-allergic patients unable to take oral med
Alt. for methicillin group
Cephalothin
Keflin
First (Narrow Spectrum)
Injection
Streptococci (except penicillin resistant strains), S. aureus (except MRSA)
Cephalexin
Keflex
First (Narrow Spectrum)
Oral
Streptococci (except penicillin resistant strains), S. aureus (except MRSA)
USED IN DENTISTRY TO PREVENT JOINT INFECTION (Total joint replacement surgery, Dental procedures - Tooth extractions, Gum surgery, Professional cleanings and Orthodontic band)
Cephadroxyl
Duricef
First (Narrow Spectrum)
Oral
Streptococci (except penicillin resistant strains), S. aureus (except MRSA)
Cefuroxime
Ceftin
Second (Intermediate Spectrum)
Injection
E. Coli, Klebsiella, Proteus, H. Influenzae, M. Catarrhalis, Less active VS Gram + than 1st gen
Cefaclor
Ceclor
Second (Intermediate Spectrum)
Oral
E. Coli, Klebsiella, Proteus, H. Influenzae, M. Catarrhalis, Less active VS Gram + than 1st gen
Cefoxitin
Mefoxin
Second (Intermediate Spectrum)
Injection
Inferior to Cefuroxime VS S. aureus but increased activity VS Bacteroides fragilis and other Bacteriodes spp.
Cefotetan
Cefotan
Second (Intermediate Spectrum)
Injection
Inferior to Cefuroxime VS S. aureus but increased activity VS Bacteroides fragilis and other Bacteriodes spp.
Agents containing Methylthiotetrazole (MTT) side chain (cefotetan) interfere w/ Vit K metabolism and cause clotting problems - Use with caution in patients on warfarin or with underlying clotting problems, Agents also cause disulfiram like rxn with alcohol
Ceftriaxone
Rocephin
Third
Injection
Enterobacteriaceae, Pseudomonas aeruginosa, Serratia, Neisseria gonorrhoeae, Activity VS S. aureus, Strep. Pneumoniae and Strep. Pyogenes comparable to 1st gen. Activity VS Bacteroides inferior to cefoxitin and cefotetan
AHA RECOMMENDED as injectable premedication for penicillin allergic patients unable to take oral meds
Cefotaxime
Claforin
Third
Injection
Enterobacteriaceae, Pseudomonas aeruginosa, Serratia, Neisseria gonorrhoeae, Activity VS S. aureus, Strep. Pneumoniae and Strep. Pyogenes comparable to 1st gen. Activity VS Bacteroides inferior to cefoxitin and cefotetan
Ceftazidime
Fortaz Third Injection Enterobacteriaceae, Pseudomonas aeruginosa, Serratia, Neisseria gonorrhoeae, Activity VS S. aureus, Strep. Pneumoniae and Strep. Pyogenes comparable to 1st gen. Activity VS Bacteroides inferior to cefoxitin and cefotetan ACTIVE VS. PSEUDOMONAS
Ceftizoxime
Cefizox
Third
Injection
Enterobacteriaceae, Pseudomonas aeruginosa, Serratia, Neisseria gonorrhoeae, Activity VS S. aureus, Strep. Pneumoniae and Strep. Pyogenes comparable to 1st gen. Activity VS Bacteroides inferior to cefoxitin and cefotetan
Cefpodoxime proxetil
Vantin
Third
Oral
Enterobacteriaceae, Pseudomonas aeruginosa, Serratia, Neisseria gonorrhoeae, Activity VS S. aureus, Strep. Pneumoniae and Strep. Pyogenes comparable to 1st gen. Activity VS Bacteroides inferior to cefoxitin and cefotetan
Cefeprime
Maxipime
Fourth
Injection
Comparable to third-gem but more resistant to some Beta-lactamases
Zwitterion - Enhanced ability to penetrate porin in outer membrane of Gram - bacteria
First Generation Cephalosporins
Greatest activity VS Gram + (Few Gram - P. mirabilis, E. coli, K. pneumoniae), Good bone penetration and greater activity VS Staph., Excellent for joint prosthesis prophylaxis, More stable to bacterial beta-lactamase (Cefazolin for Methicillin group) but not good activity VS Anaerobes (Bacteroides), Excretion by glomerular filtration and tubular secretion, Probenacid will increase serum levels (Blocks tubular secretion), Adjust dose in renal impairment
Second Generation Cephalosporins
Expanded activity against Gram - including cephalothin resistant E.coli, Klebsiella and P. mirabilis, Increased spectrum of action due to greater affinity for PBP, Greater penetration of Gram - envelope and Greater resistance to Beta-lactamase hydrolysis, Cephamycins (Cefoxitin) are active against Bacteroides fragilis and Serratia marcescens - Useful to treat mixed anaerobic infections
Third Generation Cephalosporins
Good activity VS many Gram - organisms (Enterobacteriaceae, H. influenzae and N. gonorrhoea), Increased Gram - activity due to addition of aminothiazole moiety to beta lactam ring, Good CSF level for treating bacterial meningitis, Ceftazidime and Cefoperazone active VS Pseudomonas, Sensitive to some beta-lactamases from Enterobacter
Fourth Generation Cephalosporins
Similar to third but active VS Pseudomonas aeruginosa and organisms resistant to third gen agents, Greater resistance to beta-lactamase than third, Chemical modification at position 7 renders agents more stable against beta-lactamase