Cephalosporins Flashcards
What is the MOA of cephalosporins?
Binds to cephalosporin-binding proteins preventing transpeptidation process from occurring, which leads to cell wall lysis
What are some of the mechanisms of resistance?
Drug cant reach site of action, alteration to cephalosporin binding proteins, hydrolysis of Beta lactam ring, variable susceptibilty to Beta-Lactamases
What do the cephalosporins cover?
1st, 2nd and 3rd generation - gram positive
1st, 2nd, 3rd and 4th gram negative
What is the spectrum of activity?
MSSA, P. Mirabilis, E. Coli, K. Pneumoniae
What are some of the gaps in the spectrum?
MRSA, Neisseria, M. Catarhallis, Listeria, Psedomonas, Citrobacter, Serratia
What are common clinical indications?
Uncomplicated UTIs, skin and soft tissue infections
What is the activity for 2nd generation agents?
True cephalosporins are active against H. Influenzae and Klebsiella.
Cephamycins: active against anaerobes e.g. B. Fragilis + serratia
Give 3 examples of True cephalosporins?
Cefuroxime, Cefaclor, Cefprozil, Loracarbef
What are examples of 3rd generation agents
Cefpodoxime, ceftriaxone, cefotaxime, ceftazidime
What are the pharmacokinetics of 3rd generation agents?
Penetrate body fluids and tissues well. Excreted renally, ceftriaxone eliminated hepatically
What is the indication for 4th generation agents?
Indicated for multi-drug resistant infections in hospital. Cefepime is an example.
What is so special about 5th generation ceftaroline?
Its the only cephalosporin active methicillin resistant staphylococcus aureus.
What are some general PK properties for cephalosprins
A - many oral agents are readily absorbed
D - High concentrations in synovial and pericardial fluids. No 1st gen cross the blood brain barrier
M - majority excreted unchanged in urine
E - mostly renally excreted.
List 4 drug interactions for cephalosporins
Alcohol, anticoagulants, aspirin, NSAIDS, COCs, Probenecid
