Cephalosporins Flashcards
Structure of cephalosporin
6 membered ring
COOH group, protecting the ring from B-lactamase
Mechanism of effect
Bacteriocidal (cell wall synthesisi inhibitor)
Time dependent antibiotic
PAE
NAG-NAM cross binding
Resistance: Ab ovo
mycoplasma
ricketssia
chlamydia
pseudomonas. (Except 3rd gen: cefoperazon, cefatime)
Resistance: B-lactamase production
E.coli
Pseudomonas
Gram negativ and some positive
staphylococcus can be treated with cefalosporins
Antibacterial spectrum of cephalosporins- the generations
1st generation
- Gr+++ - Gr -
2nd generation
- Gr ++ - Gr ---
3rd generation
- Gr+ - Gr -----
4th generation
- Gr++++ - Gr -----
Which generation is CIA
(3) -4
what is a 4th generations cephalosporin
cefquimone
1st generation drugs
- spectrum
- characteristics
- indications
gram + : especially staphylococcus, streptococcus
Gram -: not good, cannot treat E.coli
penicillinase stable
dermatitis, otitis and UTI caused by staphloccous
2nd generation drug
- spectrum
less active against g+
better against G-: E.coli, salmonella spp, Klebsiella spp
3rd generation
- spectrum
- drugs and what they are normally used against
Gr+: weakest
Gr-: potent, active against lactamase producers, effective against pseudomonas
cefoperazone and ceftazidime: pseudomonas aeruginosa
Pharmacokinetics of cephalosporins
- absorption
- distribution
- metabolism
- excretion
absorption
- oral absorption only for 1+2 gen
- parenteral application for 3-4th gen
distribution
- depends on lipophilicity, more and more lipophilic by increasing generation
Metabolism
- not in the liver
Excretion
- bile
What cephalosporins can be used to treat meningitis? and what generation are they in
cefrtaxon and cefotaxim
3rd gen
which cephalosporins are excreted via bile?
cefoperazone
cefachlor
ceftriaxon
Cefovecin
- indication
- generation
- application
- half-life
- PAE
- dose
dermatitis, oral cavity infections and rarely against UTI.
Dogs and cats
3rd generation
5-7 days (5 for dog, 7 for cat)
PAE for 2 weeks
8mg/kg
Ceftiofur
- indications
- generation
- application and different forms of the drug
- dose
respiratory, GI (not so importnat) and UTI
3rd generation
IM in swine, SC in cattle
Na (short acting
Hydrochloride
CCFA (long acting)
8mg/kg
what is desfuroyl ceftiofur?
a common metabolite, it appears in the body and gets activily excreted by the kidney - can be excreted in active form
side effects of cephalosporins
mild toxicity
allergy
dysbacteriosis
haemotological: increases thrombocytes and RBC
tissue irritation
mild nephrotoxicity (do not combine with aminoglycosides)
Which other AB should you not combine with cephalosporin and what is the effect?
aminoglycosides, will give nephrotoxic effect
examples of 1st gen cephalosporins
oral: cephalexin, cefdroxil
Parenteral: cephapirin, Cefacetril, Cephalotin, Cephalozoline
Examples of 2nd generation cephalosporins
Oral: cefuroxime axetil, cefaclor
Parenteral: cefuroxime
Example of 3rd generation cephlosporins
Oral: cefixime
Parenteral: Cefoperazone, ceftazidime, ceftiofur, efovecin, cefotaxime/ceftriaxone
Example of 4th generations Cephalosporin
Cefquinome
Cephalozoline
1st gen
IV 30 min before surgery
good aainst g+
Indications for Cefuroxime
2nd gen
upper resp problem
otitis
pharyngitis
indications for cefixime
UTI
indication for cefoperazone
mastitis caused by E.coli
indications for ceftiofur
pseudomonas aeruginosa
indications for cefotaxime/ceftraxone
meningitis
fusobacterium: foot rot
bacteroides: oral cavity infections
oter anaerobic bacterias that are Gr-
indications for cefquinome
large animals
GI infectins
Respiratory infections
UTI
general indications for cephalosporins
Mastitis dermatitis, soft tissue infection respiratory infections UTI: 3rd meningitis, encephalitis: 3rd preoperaive, intraoperative: 1st Prophylaxis: 1st
