Cephalosporin Flashcards
Bactericidal, cell wall synthesis
Mechanism of action
Inhibit cell wall synthesis by binding to PBPs penicillin binding protein
1st generation
Spectrum and indications
Most G +ve cocci (except enterococci)
Enteric Aerobic G-ve bacilli :
E.coli, Klebsiella pneumoniae, Proteus mirabilis
Pre operative prophylaxis
Not preferred for other conditions
2nd generation
Spectrum
Microbes covered by 1st gen
Extended G -ve coverage
B lactamase producing Haemophilus influenzae
2nd generation indications
UTIs
Acute otitis media
Sinusitis
Gonococcal disease
Cefprozil & Cefaclor: otitis media, sinusitis
Cefotetan & Cefoxitin: mixed aerobic anaerobic infections (intra-abdominal)
Cefuroxime: outpatient community acquired pneumonia
Third gen
Spectrum
Wider activity against most gram -ve bacteria Enterobacter Citrobacter Serratia Providencia Neisseria Haemophilus
Third gen indications
Meningitis
Sepsis of unknown origin
Fever in neutropenic immunocompromised patients
Resistant strains to older cephs
Empiric therapy for life threatening infections
4th gen spectrum
Spectrum
Improved activity against gram +ve including MRSA and MDRSP (multidrug resistant streptococcus pneumoniae)
Cefepime highly resistant to B lactamses
SPACE
Serratia, Proteus, Acinetobacter, Citrobacter, Enterobacter
4th generation indications
UTIs
Uncomplicated skin infection
Pneumonia
Empiric use in febrile neutropenic patients
Adverse effects
Hypersensitivity
Skin rashes, pruritis , steven Johnson syndrome
Disulfiram like reactions
GI distress
Clostridium difficile induced
+ve coombs test (rare haemolytic anemia)
Nephrotoxicity
False positive glycosuria results in test using copper reduction method
Ceftriaxone contra in newborns receiving Ca solutions
Bleeding diatheses
Interactions
Probenecid (renal competition)
Alcohol (cefmetazole, cefotetan, cefoperazone)
Antacids
H2 antagonist (cefpodoxime cefuroxime)
Iron supplement (cefdinir)
Iron fortified foods (cefdinir absorption reduced)
Fifth gen
Ceftazoline
MRSA
Suffix and general rules
1st = pha, fa, phra (cefazolin, cephalexin, cephradine)
2nd = cefaclor, ceuroxime, cefotetan
3rd = ime, one, ten , nir (ceftriaxone)
4th= pi. (cefipime)
5th= ceftazolin
Gram +ve activity goes in descending with generation no
Gram -ve goes ascending
BBB crossing
1st gen = No BBB
2nd gen = cefuroxime only
3rd gen = BBB
4th gen = BBB
