welcome to another MedCram lecture we're going to talk about cephalosporins
and specifically the different generations some representative
antibiotics in each class and what are the unique things about those
generations and what they do in their coverage so there are five generations
of cephalosporins we've got the first generation cephalosporin we've got the
second which we'll talk about the third which is the workhorse of the pneumonia
scene we've got the fourth generation which has got the Pseudomonas coverage
so also in the third and then finally the fifth which is an interesting
generation that we'll talk about as we go from first the second to third to
fourth you'll see that there is better and better gram-negative coverage so at
the very beginning with the first generation cephalosporins we have
medications like cefazolin and cephalexin and these antibiotics really
have no anaerobic coverage so no an aerobic coverage but what they did have
a lot of coverage for is gram-positive so this is gonna be our gram-positive
box and this is gonna be our gram-negative box so in terms of gram
positives it had really good staff and actually pretty good strap coverage so
where do we see these things being used we see these things being used in for
instance skin infections because this has got really good gram-positive
coverage no anaerobic coverage good staph and strep and in terms of
gram-negative it would still take care of you know your regular gram negatives
like e.coli like Proteus and like Klebsiella okay when they went on to
second generation cephalosporins here we're talking about medications like
cefuroxime and likes fot ten so the biggest thing about this was that
now we had an aerobic coverage that was the big thing and so as a result of that
we're now we're looking at intra-abdominal and the reason why we
could do that was because there's a lot of anaerobic bacterial intra-abdominal
ewwww but in terms of the staph and strep it stayed the same going from the
first generation to the second there was really no change so we didn't lose much
in terms of staph and strep but going from first generation the second
generation we actually got a little bit better gram-negative coverage so that's
what really made it really well in terms of intra-abdominal infections the second
generation was better in terms of that okay let's go on to the third generation
third generation cephalosporins there's three major examples and you
should know these one of them is ceftriaxone
the other one is cefotaxime and the last one is a very important one called
ceftazidime we'll talk about that one a little bit in terms of anaerobic
coverage well it lost it again so not anaerobic no anaerobic coverage
here whereas we had it back in the second generation now in terms of gram
positives here it was okay definitely very good in pneumococcus okay but in
terms of staff probably not as good a coverage in terms of staph aureus
because it has good pneumococcal coverage third-generation cephalosporins
were really good at lung lung infection so we're talking about
community-acquired pneumonia now there's a couple of things I should mention here
and that's very specifically that ceftazidime is covering Pseudomonas and
that's an important thing that we're going to have to bring up here when we
talk about gram negatives is that here it's even
better you can see as we go up the list here in terms of generations that the
gram-negative coverage just keeps getting better
specifically if you're using ceftazidime you can now cover Pseudomonas but even
if you're not we're talking good coverage with Neisseria gonorrhea we're
talking about Enterobacter ìshe so enterobacter we're talking about
Serratia so Enterobacter Serratia a Neisseria gonorrhea it's better and
here's the big one if you use ceftazidime it'll cover Pseudomonas now
that's a big one because Pseudomonas is the infection that people get in nursing
homes specifically in their lung so that's third generation probably one of
the best up to that point in terms of gram-negative coverage now fourth
generation the big one that you got to know there is cefepime now cefepime is
important because it also covers the big p the big Pseudomonas okay in terms of
anaerobic coverage still no anaerobic coverage so so far the only one that
actually covers anaerobes is the second generation cephalosporins now the fourth
generation cephalosporins were something quite amazing because what it did is it
took the strength of the first generation for gram positives okay so
really strong and it added the great gram negative coverage of the third and
made it strong so cefepime is really outstanding and so
what were we using these for we were using these for very serious infections
anywhere so I'll put serious here because it's got excellent coverage
strong gram positive Strom gram negative and the extra bonuses
it covers Pseudomonas so we can think of like for instance immunocompromised
patience or fever of unknown origin okay so this fourth generation cephalosporin
had excellent excellent coverage now when we go to the fifth generation the
fifth generation cephalosporin is kind of unusual because we've got different
players in that generation which are very very different from each other
the first one that I want to talk to you about is a long one called sift all is
Ain and it actually is combined with taser baktun which is a beta-lactamase
inhibitor okay Saif attalos aim heizo backed him and the other one is sift
Harleen these are very different 5th generation cephalosporins again for the
second time we have good anaerobic coverage you should know that should
really just the second generation and the fifth generation that have an
aerobic coverage but let's talk a little bit more about these two players
ACEF tall the same Tazo back down this first one what they did was they took
ceftazidime okay that structure and they basically made it better and so that
this is the actually the most potent anti suit ammonal cephalosporin that we
currently have and they added on a Tazo back Tam which is a beta-lactamase
inhibitor so this is a super anti sunomono that works well so just to
review we've got three cephalosporins that have anti sunomono coverage and i
think that's important to know you should know that ceftazidime cefepime
and seth tall is a nar now we use ceftriaxone as our third-generation
cephalosporin to treat community-acquired pneumonia
notice that ceftriaxone or Rocephin does not have any anti sunomono coverage so
if a patient is coming in from a nursing home or some institution or a hospital
that they're at risk for having Pseudomonas you should not use
ceftriaxone do not use ceftriaxone because ceftriaxone has no anti-suit
ammonal coverage the only one that has pseudomonas coverages is ceftazidime
cefepime and cept Allah Zayn okay so this is a great anti sunomono medication
now what is Saif Tarly what is so good about it actually satara lean the fluoro
is the trade name actually covers em are sa it is the only cephalosporin that can
actually treat mr si okay so that's pretty important it's currently
indicated for skin and soft-tissue infections and also community-acquired
pneumonia it has not as of this taping gotten the FDA approval for Mrs a
pneumonia one other bit of advice information I want to give you is
sometimes when they're actually testing bacteria like gram negatives for
cefepime they'll notice that it is sensitive to cefepime
but it's not sensitive to any other cephalosporin this you should think
about in terms of if it is possible to be an extended spectrum beta lactamase
if they are you should not use any cephalosporins whatsoever and should
switch to the mono lactam and we'll talk about that in one of our next lectures
so just to review again here we've got the first second third fourth and fifth
generation the first generation was really good on grand positive staph and
strep did not have anaerobic coverage and had so-so gram-negative coverage
really good for skin infections like cefazolin
cephalexin okay but because it had good gram-negative coverage like e-coli you
could use it in simple urinary tract infections going into second generation
we've got anaerobic coverage we've got better gram-negative coverage this is
intra-abdominal because of that anaerobic and better gram-negative
coverage third generation is the workhorse for community-acquired
pneumonia because of the ceftriaxone but you should also know that it also holds
ceftazidime which is an anti-suit ammonal and it's got one of the best
grande negative coverages out of all of the generations four generation took the
best of both worlds took the first-generation gram-positive
coverage and it took the third-generation gram-negative coverage
put it all together and you got cefepime which is anti pseudo monel okay
so it was for serious infections where you needed really good broad-spectrum
antibiotics finally the fifth generation has two odd players that are really
different from each other SEF tolas ain which is the anti pseudo
monel which you have to worry about in in a hospital-acquired infections but
also mrs a coverage with sift Harleen also something you have to worry about
in hospital acquired infections two different drugs same generation okay
well thanks for joining us