beta-lactam + dihydrothiazine ring with side chian.

Same basic mechanism as penicillin except they are resistance to beta-lactamases

1st generation Cephalosporin

IV

Good vs G+ and the following PEcK G- organisms:

Proteus mirabilis - enteric, only infects when it leaves the GI tract, commone cause of UTI, urease +

E. Coli - eneteric, most common cause of UTI, traveler's diarrhea

Klebsiella pneumaniae- nosocomial RTIs but can cause UTI

1st generation cephalosprin

oral

Good vs G+ and the following PEcK G- organisms:

Proteus mirabilis - enteric, only infects when it leaves the GI tract, commone cause of UTI, urease +

E. Coli - eneteric, most common cause of UTI, traveler's diarrhea

Klebsiella pneumaniae- nosocomial RTIs but can cause UTI

1st generation cephalosprin

oral

Good vs G+ and the following PEcK G- organisms:

Proteus mirabilis - enteric, only infects when it leaves the GI tract, commone cause of UTI, urease +

E. Coli - eneteric, most common cause of UTI, traveler's diarrhea

Klebsiella pneumaniae- nosocomial RTIs but can cause UTI

2ned generation Cephalosporin

oral every 8h. Serum Sickness

Less G+ and more G-

Covers PEcK + H. Influenza, & Neiseseria

Cefuroxime

2ned generation Cephalosporin

q12h, Oral=Ceftin, IV/IM=Zanicef

Less G+ and more G-

Covers PEcK + H. Influenza, & Neiseseria

2ned generation Cephalosporin

a cephamycin. Active vs Bacteroides fragilis. IV/IM

Less G+ and more G-

Covers PEcK + H. Influenza, & Neiseseria

2ned generation Cephalosporin

IV/IM - methylthiotetrazole side-chain antagonizes vitamin K --> hypoprothrombinemia. Must supplement with vitK

Less G+ and more G-

Covers PEcK + H. Influenza, & Neiseseria

3rd generation Cephalosporin

IV/IM. Highly protein bound, easily displaces bilirubin from albumin. Do not use if <3mo old to decrease risk of kernicterus unless as a single dose for Gonorrhoeae Conjunctivitis.

Good activity vs Meningitis (generally from S. Pneumonia and N. Meningitidis)

Half excreted in bile, half in urine.

FDA Warning: Do not use w/ Ca-containing products in pts <28 days old even if by different routes (might precipitate in lungs and kidneys). Give sequentially

Cefotaxime (Claforan)

3rd Generation Cephalosporin

IV/IM. Parent & metabolite active. Will also cover Bacteroides

3rd Generation Cephalosporin

oral

Cefdinir (Omnifcef)

3rd generation Cephalospring

excreted unchanged. Binds to Fe. Reddens feces in infants

3rd Generation Cephalosporin

IV/IM, neurologic side effects (myoclonus), EEG changes with increased risk of epilepsy

4th generation Cephalosporin

IV/IM

for G- rods resistant to 3rd generation

Good CNS penetration. Neurologic side effects (disorientation, myoclonus), EEG changes (increase epilepsy). Mostly renal excretion

4th generation Cephalosporin

 pro-drug. hydrolized by esterases during absorption

Side Effects of Cephalosporins

• Hypersensitivity - risk of cross allergy with PCN greatest for 1st gen. but negligible for 2nd and 3rd.
• Nephrotoxicity - low risk compared to aminoglycosides
• FDA warning - immune mediated hemolytic anemia