S1E41 Antibiotics

All right, so antibiotic review. This is going to be a triple distilled
antibiotic review. I'm going to go over every single antibiotic or every single detail,
nor would you want me to. There's a ton to know, but
I'm focusing on the high yield stuff, the stuff that always seem to come
up on exams. Thank you so much, as always for your support,
the really nice comments. I'm going to say it on every single podcast because
I really do appreciate it. And if you haven't checked out the YouTube channel,
please do is Cram the pants on YouTube has some good visuals to go
along with the audio. All right, so let's get started with antibiotics.
We'll start with the beta lactams, your penicillin, and sephalosporins, carbon penoms,
amount of backdam, and then we'll start with penicillin, and that's our
og antibiotic. That was our first So let's go ahead and get started with
those, and we'll break down each individual penicillin to kind of talk about the
evolution of penicillin and how we had to change with the evolving bacteria and the
resistance. So let's start with penicillin, penicillin G, and penicillin v or
VK. So penicillin G and penicillan VK what are they good for? They're
good for grand positive organisms. They have really good grand positive coverage, but
unfortunately they've been around so long there's a ton of resistance against them, and
they're not good for a lot of things anymore unfortunately. So what are our
high yield indications. It's gonna be syphilis, STRAP, dental infections, and
rheumatic fever. Those are the ones that seem to come up often, particularly
syphilis, so first line for STRAP. That's why we also see an indicator
for a rheumatic fever which is caused by STRAP. Can be used for dental
infections because it does cover most oral anaerobes. But the high yield one,
like I said before, that's cyphilis. That's the one they'll always ask you
about on exams, and that's when you use penicillin G that injectable form.
Just an fy in regards to the strep eringitis coverage. So in real life,
penicillin V has really good coverage for STRAP and it works well. But
are you actually going to use it in clinical practice? Probably not often,
and you'll see when you're out in clinicals, it's not used often. Moxiscillin
is the one that we always really use for STRAP in real life because one,
it's much more palatable, particularly in children. Penicillin V does not taste
good. And then the second thing is a moxiscillin has twice daily dosing compared
to penicillin V which can be up to four times a day. So all
penicillan VK works really well to cover strap and might be your exam It might
be your answered choice on the exam question. In real life, you're probably
more often going to use am oxycillin, which covers it just as well.
All right, So penicillin it was our first antibiotic, but eventually bacteria started
to evolve and resist penicillin by producing something called penicillanase, So we had to
go back to the drawing board. We had to come up with a semisynthetic
penicillin called penicillinase resistant penicillin also known as anti staffhlococco penicillin. So penicillinase is
an enzyme that's produced by bacteria that destroys the beta lactam ring of penicillin,
making it ineffective. Well, now we had this antibiotic class that we created
that was resistant to penicillanase, the medicines class or nafficillin oxycillin dicloxyscillin. Back
in the day, this list used to include methycillin. That's how we came
up with the name MIRZA, or methysillin Resistant staff oreus. We don't use
methyscillin anymore due to its poor side effect profile, but just be aware that
this used to be in that class, and that's how we came up with
MIRSA. What do they cover? They cover gram positive again, just like
the ones we previously went over, but particularly beta lactimates producing staff areas.
High old indication. There's just one MSSA methyscillin susceptible staff areas. So whether
it's bactoreemia, asteomyelitis, cellulitis, endocarditis, if it's from MSSA, they're
generally going to be your drug of choice. These men basically exist to treat
staff. That's the only indication I would know for them. That's really the
main indication in real life. Nafcillin oxycillin dicloxycillin think about staff. MSSA not
good for marca though, but methysillas sensitive or susceptible staff oreus. That is
the indication for these medications. All right, So we created a penicillin which
covered strap and staff so most of our gram positive organisms. But these last
two generations I just spoke about didn't really cover gram negatives, or at least
not very well. So we had to create a penicillin that did. So
what we developed was amino penicillans for that specific reason to fight gram negative infection.
So amino penicillans, you'll notice they have the AM prefix, so amoxycillin
ampicillin. So if amino penicillans, we brought in our coverage with penicillin,
and now we have the ability to fight gram negative organisms as well as gram
positive. So amoxiscillin is your oral medication. Ampicillin is your parental iv im
And if you wanted a way to remember those, it's probably pretty I probably
already know because amoxycilla is so common. But moxyscillin the third letter has an
OH, so that's oral. Ampicillin in the third third letter has a P,
so that's parental. So that's just a way if you've forgotten an exam
maybe high yield indications qutotitis, media, strep, pharyngitis, listeria. Those
are the three big ones I would know for yourmino penicillans, titus, media,
strep, lesteria. There's some other hot less, high yield indications.
Remember maxycillina is one of the medications used to treat hpylori. Remember in your
triple therapy CHLORITHRUMYC and amoxyscillin PPI. It's another option in treatment for lyme disease,
although doxy is generally preferred unless the patients pregnant or young young child.
With some caveats I'll discuss when we get to the tetracyclines, but generally remember
otitis, media, strep, listeria. Know those all right. So this
subclass of penicillin worked well. We picked up some gram negative coverage in addition
to our gram positive. But the problem was this class was susceptible to beta
lactamase. So beta lactamasis are beta lactamase our enzymes produced by bacteria that break
open the beta lactame ring in activating the beta lactam antibiotic. So we had
to find a way to help these antibiotics resist this. And what we did
was we added a component onto the antibiotic called a beta lactamase inhibitor, and
what we came up with was our beta lactamase inhibitor penicillins. So we take
the same antibiotics. We just went over moxycilla and ampicillin, and we added
a beta lactamase inhibitor which prevents the beta lactamase from eating the beta lactam ring
and destroying the antibiotics. You can just think of it as a shield for
the antibiotics. So we're just taking the two antibiotics, a moxycillin ampicillin,
and we give them their shield against beta lactamase. The for amoxicillin is called
clavilanate or claviulonic acid, and that combo, the brand name is known as
Augmentin. And then with ampicillin, its shield is called soulbactim and we have
unison that brand name for that combo. So that's all we did. We
took am oxycillin, gave it clavilanate, We took amposilla, we gave it
soul back to him, and then we covered we protected them against these betolactomas,
and that brought in our coverage once again. So now we had coverage
of gram positive, gram negative, and then we also added some really good
coverage of anaerobes. And that's the key is picking up that good coverage of
anerobe with these betolactamase inhibitors. So again, the meds in this class or
a moxycillin clavulanate also known as augmentin, ampicillin soul backtim also known as unison.
So what are the high yeldentications for these medications. Cute cine eucitis.
Moxyclave is first line animal bites including human bites too, dog, cat,
human, All of those animal bites are going to be covered really well with
this class. And then aspiration ammonia because remember aspiration ammonia we know is commonly
caused by anaerobes. We know we just talked about, this class is a
good choice for coverage of anaeropes. Also be aware amoxyclav can be used this
first line agent for cute otitis media as an alternative to amoxicilla in some specific
cases. But those are your high yield ones, all right. So we
have all of these different types of penicillans. We covered a wide variety of
organisms. What about pseudomonus coverage, We haven't talked about that, and that's
where our anti pseudomonal penicillans come in. So our anti pseudomonal penicillans, these
are a broad spectrum antibiotics. You're not going to use these in your average
patient. It's really just for your sick patients. The key here is their
coverage of pseudomonas, so they cover most organisms gram positive, gram negative anaerobes
pseudomonas, which is obviously the key and what they're most commonly used for.
It's really easier to focus on what they don't cover because they cover so much.
So they don't cover mersa and they won't cover your atypicals like microplasma legionella,
but most other organisms they're going to have coverage for their really broad spectrum
antibiotics. So the meds in this class are going to be piperus cillin,
taso backdam which is also known zocin. Again, this one has the best
coverage for pseudomonas of the two, and then tick our sillin clavilanate still cover
pseudomonis, but not as well as pip tazo. So there's not really any
specific high old indications. I would say to know for these, but just
be aware, particularly when peudomonis is suspected, like in hospital acquired pneumonia.
This class is going to be utilized, particularly piptazo It can also be used
in some severe soft tissue infections and trebdominal infections as well. So what are
the ad rs? What are the adverse drug reactions that you need to know
for the penicillin class in general, So just a few that I would focus
on. One is their hypersensitivity reaction, because of all the drug classes,
penicilla is the class most associated with hypersensitivity reactions. Second one is some of
the hematologic reactions you can see in this class, So thrombostopenia, neutropenia,
immune mediated hemolytic anemia, all possible in the beta lactam class in general,
but particularly with the penicillin antibiotics. And then finally GI problems. Now this
is non specific because all antibiotic classes can cause GI problems, but in the
penicillin class there's a couple of main culprits to look out for. That's going
to be ampicillin, amoxis cillin, which are known for causing diarrhea, particularly
augmented, which remember is the combo of amoxysillin clavilane. Penicillan has the highest
incidence of diarrhea of all the penicillin. So be aware when you're prescribing that
medication of your patients if you can maybe just give them playing amoxis cillina instead
of augmentin, you'll be doing them a big favor, all right. So
that's our penicillans are the main things that you need to know for those.
Let's move on to our cephalosporins. All right. Well, the cephalosporons always
seem to give people problems, but I've come up with a few mnemonics that
I think will help you with these, So hopefully that'll be helpful to help
you to remember the cephalosporins the way you need to know about them. All
right, So before we jump into the cephalosporins, I want to review an
easy way to remember the coverage for cephalosporins, particularly, they're gram negative verse
gram positive coverage. So as a general rule, as the cephalosporin generations go
on from first to second to third to fourth, they lose gram positive coverage
and they gain gram negative coverage. It's not one hundred percent accurate, and
in every case there are some exceptions. But as a general rule, if
you remember this fear exams with the cephalist borns, as the generations go on
from first to fourth, they lose gram positive coverage and they gain negative coverage.
So in general, first generation is really good at covering gram positive,
not so good at gram negative, and fourth generation really good gram negative coverage
but not so good at covering gram positive. Fifth generation doesn't really follow these
rules. It's kind of really great at gram positive. So don't worry about
fifth generation. But first to fourth, remember that your first generation is going
to be really good at gram positive, your fourth is going to be really
good at gram negative, so loses gram negative as goes on. The way
that I used to remember that, it seems so simple, but then when
you're having an exam question, you've a thousand things in your head and you
see a first generation and you're like, wait, is this the one that's
good at gram negative gram positive. So the way that you remember that,
as you know, in the Olympics or anytime you have like some kind of
race or whatever, they have those podiums where you have the person standing in
first place. They're standing in the little boxes that says like first place,
second place, third place, etc. Well, the person in first place,
aka your first generation person in first place is super positive they got first
place. They're so happy, they're so positive, they're almost completely absent of
any negative feelings at all. That's because your first generation covers gram positive but
very little GRAM negative. The person in third and fourth generation, they are
not very positive at all. They're mostly negative because they're like almost in last
place, third and fourth place. They're very negative but very little positive.
They're not happy they did not get first place. So as you go on
from first, second, third, and fourth, you're losing that positive feeling
because you're going further on in the places, and you're gaining negative feelings because
you're further on in the placement. So that's how you used to remember it.
It's just a simple way to kind of remember with the cephalisborns as far
as their coverage as a general rule. All right, so let's go ahead
and get started with the generations. We'll start with our first generation Cephalis born.
That's going to include cephalexin which the brand name is Keflex. That's your
po variety, and then cephazolin, which is known as anseff. That's the
brand name and that's your IV. So these have really good gram positive coverage.
Like I just went over so staff strap skin infections. It does have
some mild gram negative coverage like free coli, proteus, clepsi yellow, but
the main usephere first gens. What they do best is gram positive organisms.
Remember you're on the first place podium. You're super positive. You got first
place. You're covering gram positive really well, so high old indications. There's
really two things that I think you should know, skin infections and surgical prophylaxis.
So skin infections MSSA, So all of your skin infections involving staff fulliculitis,
peronnikia MSSA, be thinking of your first gens particular or lead with sephyluxin,
which is your oral antibiotic of this class. Surgical prophyloxis is the second
thing I think you should know cephozolin. So when you do your surgical rotations,
you'll hear this before every every single surgery. Two grams of antef on
board. It's basically the most commonly used antibiotic for surgical prophyloxis. So know
that for sefazolon. So again two things skin infections, MSSA, methyslin,
susceptible stephorius. You should be thinking that with your first gens, particularly selection
cephalexin and then surgical prophyloxis one hundred percent cephyzolin. All right, So those
are your first gens, not allowed to know their second generation sef oxyten,
sefuroxen, cepiclo, cefot tm. So that's a lot, a lot of
weird names. How you're going to remember that those are all your second generation.
So what you remember is you think of two furry fox drinking tea on
the floor. Again, two furry fox drinking tea on the floor. So
two arry helps you remember your second generation furry. That helps you remember rock
seam fox. That's sefoxytin drinking t cefot tan on the floor, sefa cloor.
So that helps you remember again the meds that are in this class.
Two furry fox drinking tea on the floor. Remember that you remember your second
gen cephalosporins. So compared to first gen, weaker gram positive coverage, but
broader gram negative coverage picks up coverage for enterobacter Icia. It also does and
this is the key. Have anaerobic coverage, good anaerobic coverage for basically all
the Cephalis sporins. So first gens have better gram positive coverage. Third gens
are going to have better gram negative coverage. So the second gens are kind
of like the forgotten middle child. But the key, like I said,
for your second gens is their anaerobic coverage, and that's with sef oxytin and
cefo t tan particularly good for your pelvic infections and trabdominal infections. That's what
you'll normally see them test it on. So for high old indications, they
do have indications for covering UTIs, they have indications for covering resp praetory infections
line disease second line to doxy. But for the sake of an exam,
what you'll need to focus on is the intrabdominal and pelvic infections involving your anaerobes
like bacteroids. When it comes to second gens, that's what you're going to
be tested on. That's what I would focus on. So again, HYLD
indications intrabdominal and pelvic infections, cefottan and sefoxyten really good for PID for pelvic
inflammatory disease. There is some resistance seen in cephottan from B for jealous so
for intrabdominal infections might not be the best choice anymore. But remember for PID,
Cephottan and sefoxyten have really good coverage. So that's what you should focus
on for your second gens. I wouldn't worry about anything else because really that's
what they have best coverage of, and that's what you'll probably see on an
exam question. All right, So moving on to our third generation cephalosporins.
That's sef triaxone, cefotaxin, ceftazidine, some others in this class, sef
podoxine, but really those are the three that ever seemed to come up.
Those are the ones that I would focus on. So how do you remember
them? You remember, if you try taxing me, you won't get a
dime. You can try taxing me, but you won't get a dime,
so you can try that. Sef triaxone also try helps you remember your third
generation taxing cefotaxim, but you won't get a dime. Seftazidine again, so
you can try taxing me, but you won't get a dime. Triaxone.
Also try third generation taxing sefotaxime, but you won't get a dime seftazidine.
All right, So these have really excellent gram negative coverage, including pseudomonus.
With seftazidine, gram positive coverage is decreased. Remember you're in third place.
You're pretty negative at this point, not very positive. Some antibiotics in this
class, like seftazidine, have virtually no gram positive coverage at all. Your
third gends mainly about your gram negatives and pseudomonis. With seftazidine, it's important
to remember that seftazidim has pseudomonus coverage because that always seem to come up.
And I have another another mnemonic for you to remember that. So if you
sue me, you won't get a dime. If you sue me, you
won't get a dime. So sue helps you remember sue domonas you won't get
a dime seftazidine. So if you sue me pseudomonas, you won't get a
dime seftazidine. So that helps you remember seftazidine only third gen that covers pseudomonas.
What are your high old indications gonococcal infections. That's really big. SEF
triaxon meningitis. So your third generation cephalosporins cefotaxim, sef triaxone are the beta
lactems of choice and impure treatment of meningitis generally combined with other antibiotics for their
synergistic effect. And then community acquired pneumonia hospitalized. All right, those are
your high old indications. Now, fourth generation this is very simple. Last
two generations are really easy with your cephalisporons because there's only a couple of meds.
So fourth generation ceph apem, that's the only fourth generation cephalosporin. Nice
and easy. What a sephapem cover gram negative including pseudomonas, which is really
important. It has very limited gram positive coverage basically just for MSSA, but
remember gram negative pseudomonus. That's the key, all right, So you get
some gram negative coverage, little gram positive coverage mainly for staff. But remember
pseudomonis. So there's not a lot to know about cephapeine basically, just that
it's a fourth generation sephless sporin and it has good coverage against pseudomonis. That's
all i'd remember. How do you remember that. So instead of remembering cephapeam,
remember SEP four peam. So instead of cephapeem, remember se four peem.
The number four that helps you remember it's a fourth generation cephalis sporin.
And then it helps remember Pseudomonis, which has four syllables, so pseudomonas four
four syllables. That helps you remember coverage of pseudomonis. So again instead of
cephapem, remember SEF four peam. Fourth generation selphless sporin four also stands for
the four syllables that are in Pseudomonis. Helps you remember that it covers pseudomonis.
Those are the two things that I've remembered for it, I wouldn't worry
about anything else, all right, Next generation, fifth generation Sef Tarolin.
It's another easy one. It's really the only one you need to know.
If you're outside of the US. There's another fifth generation Cephalis born called Sef
Tobra Paul here in the States that we just have Sef tarrolein. So that's
all you need to know Sef Tarlen. The main thing is that it's the
only sephless sporn that covers mersa. That's all I would focus on MRSA.
It's the unique thing about it. It's the primary use for the drug,
and that's what you're going to be tested on. So again, two things,
just like in the fourth gend that you need to know for this one.
Two things that you need to know. Sef Tarlene, it's a fifth
generation sephless born. And then two it covers Mursa. So how do you
remember that? So instead of remembering Sef Tarolene, remember Sef Starlene. So
instead of Sef Tarlene, remember Sef Starolene. And then when you think of
a star, how many sides does a star have? It has five?
That helps you remember your fifth generation sephless born. And then when you look
out into the stars, what's the closest planet you can sometimes see and that's
Mars. And what is Mars rearranged? Mars is just Mursa rearranged, the
letters rearranged, So mrs A M A R S. That's just those letters
of Mars rear arranged. So that helps you remember Merca coverage. So again,
Sef Tarolin, just remember star Alene. Think of a star, five
sides to a star, fifth generation sephless born. And then when you look
at into the stars. You can see Mars, which is our closest planet.
Mars is just MRSA. The letters rearranged. That helps you remember this
is the only sephileis sporning that has MERCA coverage. You're done. Those are
your sephless sporns. Let's keep moving on with our mono backdam. So monobacktam
as trion m that's the only one as trionam, and this does not have
a lot to know about it. There's really just one thing. So mono
backdams as trionam cover gram negatives only including pseudomonas, so basically just gram negative
aerobes, no gram positives. So obviously you know MERSA doesn't cover anaerobes gram
negatives only including pseudomonas, although there's actually a pretty significant rate of resistance in
most institutions against it, so normally need to utilize impure double coverage. So
mono backdam's the main thing about this one. This is what you need to
remember about as trionam. No cross reactivity with other beta lactam antibiotics. You
can give it if they have a penicillin allergy or a selphless sporin allergy,
it's the main thing you need to know and possibly the only thing you need
to know for this medication as trion Am, as far as exam questions just
exist for this one thing and the vignette. They're going to give you a
patient that has a severe anaphylactic reaction to penicillin, for instance, and then
they're going to say which antibiotic class would you give them for their infection.
They're going to have a bunch of beta lactam class antibiotics. They're going to
give you cephless sporins in there, they're going to give you penicillans, and
then as tree andam is going to be in there, and that's going to
be your answer. So remember no cross reactivity with other beta lactam antibiotics.
Little fyi here, though, I don't think they'll be evil to you on
the exam and do this to you. But as treonam, like I said,
you can use it in sephless sporon allergies penicillin allergies, but the exception
is seftazidine. They share a similar side chain. So again I don't think
they're going to be cruel and do this to you. But in real life,
remember that, so you can give them in pay with penicillona sepfhless sporin
allergies. The exception is seftazidine. Remember that similar side chain, so that
can trigger the same allergic reaction. And then we know that seftazidim is a
third generation sefhless sporn. How do you how do we know that? Remember,
if you try taxing me, you won't get a dime seftazidimee. And
then we also know seftazidim also cover pseudomonus because if you try suing me,
you won't get a dime. All right, Just trying to reiterate that,
so you remember that the other thing too. I don't think this is as
important, but as tree and am also doesn't cause any renal toxicity, so
you can use this in patience with renal insufficiency. I don't think it's as
important, but just a little extra thing for you to know, all right,
Moving right along to our carbon penem. So that's immopenem selastin meropenem and
ertepenem just an fi immopenem unlike merropenam and ertepenem. It's never administered alone.
As you can see, I said it's immopendum selastin. That combo, it
always gets combined with selastin. The reason is because if you give it by
itself, that actually gets inactivated by the proximal renal tubule and it can lead
to necrosis of the proximal tubule. So you'll always see this carbon penum combined
with selastin. All right, so what do carbon pendums cover. They're extremely
broad spectrum antibiotics. They cover a lot so gram positive, gram negative,
including your espl organisms, pseudomonas, anaerobes. So these are about as broad
spectrum as antibiotics get. They cover everything, like I said, gram positive,
gram negative, including those extended spectrum beta lactomass pseudomonas, although there's one
exception I'll get to in a minute. They cover anaerobes including beef jellous.
This is another one where it's just easy to remember what they don't cover,
and really that's just MERSA and your atypicals. Otherwise you can pretty much use
these for anything else. And that's why in practice you're not going to do
that, because really broad spectrum drugs should rarely be used because they breed resistance.
These are basically your silver bullet. They're used for severe infections where you
don't know what the bug is. The person's crashing, they're dying, so
you just have to throw everything at them. You can't be concerned with the
resistance and everything else, so you're not going to use these often. Now,
I mentioned before these cover Pseudomonus within exception, so that exception is ertapenem.
Ertapenem does not cover pseudomonus. It's the only carbon pendum that does not.
And I actually had a question on this in school, which I think
was kind of cruel, but anyways, I used to remember that ertapenem is
the exception to the rule where all other carbon penums cover pseudomonus. It's the
only one that does not. And ertapenem is the only carbon penum that starts
with an E. So when you see E, remember that means exception because
it's the exception to the rule that are all carbon pendums cover pseudomonus, it
does not. It's the exception, only one that starts with an Eerdepenem.
Remember that as far as is your adverse drug reactions for this CNS toxicity.
So they can lower seizure threshold, particularly with immapenem. That's really all I
would know for those that's the end of your beta lactam. So you're going
to get a lot of question from those, So know those pretty well beta
lactums of course, penicillin, cephalis porins, carbopenams, mono backdamps. Let's
keep moving a longer. We're going to go onto our aminoglycosides. That's gentomycin,
tobermycin, mcacent neomycin, streptomycin. So these cover gram negatives including pseudomonis,
little to no gram positive coverage, no anaerobic coverage, basically just gram
negatives for your aminoglycosides. There's not really any high old indications that memorize for
aminoglycosides. There's really few instances where you use these as monotherapy fort with systemic
immeno glycosides. Not your drops I'm talking about like for your infections, but
really just two instances where you use these as monotherapy with systemic amminoglycosides. That's
two laurmia in plague. So not exactly your high yield diseases. You can
use it for its synergistic effect with other drugs and endocarditis, but over all,
the highest yield thing about amminoglycosides is actually their adverse drug reactions. I
remember being asked about in clinical rotations about this on exam USTs. This is
probably the most important thing to remember. So adverse drug reactions you need to
remember. These drugs can be both autotoxic and nephrotoxic, so autotoxicity aminoglycoside induced
autotoxicity can result in vestibular or cochlear damage and then nephrotoxicity. Ten to twenty
percent of patients can experience some degree of nephrotoxicity with these meds. In most
cases, aminoglycoside nephrotoxicity is actually reversible though much Obviously it's a good thing,
all right, So how do you remember the main things that you need to
know about your aminoglycosides. So all of your memno glycosides end in ci N,
so gentomycin tobermycin, I'm a casin ci N. They all end in
I know there's other classes that also end in ci N. You just kind
of have to be familiar with these ones and remember for thisneumonic to work.
But remember they all end in ci N. So what does ci N stand
for? Cion stents For a couple of things. One it stands for coverage
includes negatives because that helps you remember. This is basically just covering your gram
negative organisms. So ci N stands for coverage includes negatives, gram negative organisms,
and then ci N also stands for cruscious incus and nephrons. Remember incas
is one of your auditory oscles that helps you remember your autotoxicity. And then
nephrons, of course you know, is the functional unit of the kidney.
Helps remember the nephrotoxicity that can happen in these drugs. Remember all of your
drugs and in cin in this class, coverage includes negatives. This is mainly
covering gram negatives and then crushes incas and nephrons because you can cause autotoxicity and
nephrotoxicity with this drug class. All right, moving on to our tetracyclines doxis
cycling, tetracycline, minnocyclines. So a few different meds in the tetracycline class,
but basically this is the doxycycling show. Most things you need to know
about the tetracyclines will be about doxy, so make that your focus. This
is another one that has a pretty broad spectrum of activity gram negatives gram positives,
including mersa atypicals, and then you're weird stuff. So weird stuff,
what's that? Well, anytime you have some odd organism or unusual pathogen,
we should be thinking about using a tetracycline. So vibrio, brucella, Q
fever, anthrax, line disease, they're all covered by tetracyclines. Usually,
of course it's going to be doxy. So for your high yeld indications,
it's really just doxy that can that you have to focus on. There's not
a lot of high old indications for mentocycline and tetracycline. Mentocycline is mainly just
used for acne. So the three things that you need to know for a
doxy are rocky mountain, spotted fever, chlamydia, and lime disease. Those
are your high heeled indications. Of course there's other things that doxies used for,
but these are the ones that always seem to come up in a vignette.
So chlamydia doxy is now first line for chlamydia. Used to be a
zithromycin, but due to superior efficacy we see with doxy compared to a zithro
the guidelines have changed and now doxy is going to be your first line.
One hundred milligrams bid seven days for your first line treatment for chlamydia Rocky Mountain
spotted fever first line. Pretty much all patients are going to get doxe.
Even in young children. You're gonnay for Rocky Mountain spoted fever, You're gonna
give doxy. Just a heads up Rocky Mountain spotted fever treatment in pregnancy.
It used to be chlorine. Fennocole used to be your first line, but
now that's even being replaced with doxy. If you look at the updated guidelines,
so Rocky Mountain spotted fever pretty much doxy all the way. Lime disease
first line, non pregnant adults and children and older children with lime disease kids
under eight, the guidelines are kind of muddy. You'll be taught less than
eight with lime disease, you're gonna give them moxycillon, and then over eight
you're gonna give them DOXE. I'd probably learn it that way for the boards
and for your exams, But if you look at the guidelines, that really
depends on the stage of the infection the child has. So if it's just
cutaneous disease. Normally you'll just give them moxicillin, but there's any signs of
neurologic involvement, you can preferably use doxy. And actually, the American Academy
of Pediatric supports the use of doxycycling for children under eight as long as it's
administered for less than twenty one days, which in doxy is the case.
So again, the three high old indications you're gonna remember for doxycycling are gonna
be chlamydia, Rocky Mountain spotted fever, and lime disease. So how do
you remember that? Well, what you do is you think of sitting on
a dock by the sea, like a nice seafood restaurant, and a dock
by the sea eating clams and Rocky Mountain oysters with a squeeze of lime.
So you're sitting on a dock by the sea, doc sea cycling, eating
clams, chlamydia, and Rocky Mountain oysters Rocky Mountain spotted fever with a squeeze
of lime over the top. And that's your lime disease. If you know
what Rocky mount oysters are, they are not seafood, but it helps the
pneumonic work. So remember again, you're high held indications for doxy. If
you think of sitting on a dock by the sea, doc sea cycling,
eating clams, chlamydia, and Rocky Mountain oysters, Rocky Mountain spotted fever with
a squeeze of lime over the top lime disease. Don't forget. Doxy can
also be used in community acquired pneumonia. But as far as the high yeld
ones, like I said, the ones that always seem to come up,
those are the three that I would focus on. There are also some high
old adverse drug reactions, so teeth discoloration. It can inhibit bone growth in
children, So tetracycline antibiotics have been associated with permanent tooth discoloration and children under
eight years of age if used repeatedly or for prolonged courses, which this does
not occur in adults, and then tetracyclines may also deposit in bone and effect
growth, which is why we're cautious using this drug in children for a long
periods of time. They can also have impaired absorption when you take them with
certain minerals and in acids like aluminum, calcium, iron, magnesium, so
certain vitamins or dairy products when taken at the same time as tetracyclines, can
chilate with the antibiotic and impair its absorptions. So remember that again that's going
to be like aluminum, calcium, iron, magnesium, So you just want
to warn your patients about this before starting the antibiotic. Normally it's good to
put it on your actual prescription when you send it off to the pharmacy.
Do not take these at the same time because of the impaired absorption and then
photosensitivity. So there's other classes that can cause photosensitivity reactions, but it seems
to most commonly come up in questions about the tetracyclines. So the effect can
range from a mild red rash to blistering on areas exposed to the sun.
So you just also want to warn your patients about this as well. Those
are the main things that seem to come up with that class. Let's move
on to our fluoroquinolons. So the first thing to know about fluoroquinolans is you're
generally going to avoid using it in your run of the mill infections. So
like RYANU sinew sitis uncomplicated UTIs, the risks outweigh the benefits, So keep
that in mind when you're practicing. Don't give cipro for a simple UTI when
you could just just as easily given macrobid, which is nitrofur intoine. Save
these class for your more complicated infections. So the drugs that are in this
class are going to be ciprofloxysin, levofloxisin, moxifloxis and those are the three
that you need to know. Let's go over each individual one and talk about
a little bit that you need to know with each one. So moxifloxis in
this is called a quote unquote respiratory fluoroquinolone. So moxi in addition to floxysin
are considered respiratory fluoroquinolans. This isn't like an official thing, but this is
kind of generally what they're known as. The reason is because both of these
drugs in this class are active against the most common respiratory pathogens including Strep.
Numo, homophilus, influenza, monexella, and that's why you call them unofficially
are respiratory fluoroquinolones. Moxifloxysin has the best grand positive coverage of all of the
three that we're going to go over also has really good coverage of your atypicals
and your anaerobes. Maxi of the fluoroquinolones, is really the only one with
decent anaerobic coverage, and because of this, it can actually be used for
some intrabdominal infections, but it's really kind of limited due to the resistance among
the bacteroid species, so it's not the best option, but it can be
used as an alternative to ampicillin, soul backdam in aspiration ammonia for its good
anaerobic coverage. So remember that, I'd say, of the three fluoroquinolans,
this is probably going to be the one you're asked about the least. Most
questions from my experience are about cipro and levofloxysin. But if you're asked something
about Moxie, it's probably going to be related to its coverage of anaeropes.
So remember that about Moxi is its anaerobic coverage that's unique in this class,
So levofloxysin. This is another quote unquote respiratory fluoroquinolone. As we went over
with MOXI, the big difference between Moxie and levofloxysin is levofloxysin also has activity
in the urinary tract, so it can be used as an alternative to ciprofloxysin
in some cases for pylonephritis your complicated UTIs where MOXI cannot MOXI has It are
truly no urine activity, so levo floxysin has really good Gram positive coverage.
It has coverage of atypicals levofloxysin As far as coverage, it's kind of in
the middle. MOXI has better Gram positive coverage. Cipro has the best Gram
negative coverage. Levofloxysin's kind of hanging out in the middle. It does have
really good strepnumal coverage, though better than moxi, which is why it can
be used as monotherapy in a community acquired pneumonia, although we try not to
use it for pneumonia to prevent fluoroquinolone resistance among the respiratory pathogens and like it
went over before, lever floxusin also does have similar coverage as seen in cipro.
For your complicated UTIs complicated like acute cystitis pylonephritis, cipron Levo can kind
of be used interchangeably, all right. That moves us onto our ciprofloxus in,
our last drug in this class that will go over. This is a
quote unquote urinary fluoroquinolone, so it's first line for pylonephritis your complicated UTIs.
Ciprofloxusin is the only fluoroquinolone with a P in it. So that'll help me.
Remember that as soon as you see your pepe stuff pylona fhritus UTIs prostatitis
in your older males, you're going to be using cipro generally as your first
line. A lot of people think the reason we don't use cipro for our
respiratory tract infections like pneumonia is that it doesn't penetrate the lungs, but that's
actually not the case. It's just that cipro has lesser activity against our grand
positive organisms, in particular strep pneumo, and that's the reason we don't use
it for most respiratory infections and reserve that from Maxi and levofloxicin, which have
really great gram positive coverage. All right, So cipro best gram negative coverage
of all of the fluoroquinolones, including the best coverage of pseudomonis. Pseudomonis has
the best gram negative coverage of the fluoroquinolones, including the best pseudomonus coverage.
Remember that so remember again as a quick recap, moxifloxysin best gram positive coverage,
the only one with anaeroba coverage. Cipro best gram negative coverage including pseudomonis
and levo floxysens. Kind of in the middle, but it has really good
strep pneumo coverage. What are your high yeld indications pylonophritis with cipro and levofloxisin.
Your complicated UTIs cipro and levofloxicin. Remember, if this is an uncomplicated,
healthy patient, you're going to be sticking to bactrum or macrobit, which
is nitroferent tone prostetitis, cipro or levo phloxicin. It can be used as
impiric therapy in your older patients and then community acquire pneumonia, levofloxisin, moxifloxisin.
These can be used as monotherapy, but generally reserve for your patients with
comorbidities, older patients or other problems as far as adverse drug reactions, the
fluoroquinolones have a bunch of adverse drug reactions that are possible. GI of course,
is the most common as in most antibiotics, but we're going to focus
on the ones that always seem to come up on exam questions and the more
unique ones. And really there's three. First one is QT prolongation, so
fluoroquino loans can prolong the QT interval, potentially leading to torsades, so we
avoid this class and patients taking QT prolonging drugs or patients with long QT syndrome
or other risk factors for rhythmias. The other one comes up a lot as
tendinopathy or tendon rupture, So fluoroquinol loans can cause tendonopathy and tendin rupture.
Most common sites is going to be your Achilles tendon, so always be careful
to tell your patients avoid vigorous exercise, will on the medication, and have
them alert you of any signs of tendinopathy, pain swelling, etc. And
then they can also and this one's pretty interesting, they can precipitate a myocinic
crisis. So fluoroquinolones actually have a black box warning for use and patients with
Mystenia gravis because they have neuromuscular blocking activity which can precipitate a mystinic crisis.
Remember that I did have that on an exam question. All right, so
that's your floroquinolones. Let's move onto our macrolides, including a zithromycin, chlorithromycin,
erythromycin. They cover a lot of things, so they cover gram negatives,
gram positives, and they cover your atypicals. This class has pretty broad
spectrum of activity. A zithromycin in particularly in particular, is going to have
the it's really going to be your drug of choice for most of your atypical
organisms. But remember they cover a lot of things, gram negatives, gram
positives, atypicals, high yield associations. Chlamydia with a zithromycin. But remember,
like I spoke about before, this used to be your first line treatment
for chlamydia. But new evidence is showing the efficacy of doxy is superior,
So most guidelines are saying doxy for us a zithro as a second line option,
but it's still a good one to know in practice because the thing about
giving is zithro for chlamydia is it's one dose. So if you have a
patient you feel it is going to be non compliant and it's not going to
take the doxi for seven days, a zithro is a good option. It
maybe second line you may not have as good of coverage, but if you
feel like the patient's not going to take the full course anyways, you can
give them one dose of a zithro. You always have to keep that in
mind. So on the exam question, the choice is probably gonna be doxy.
But just remember in real life these little things for clinical practice. Another
thing that it covers that you're probably going to hear about is Microbacterium avium complex,
so a zithromycinchlora from mycense. So your macrolides are the cornerstone of antimicrobacterial
therapy for MAC treatment and prophyloxis in your HIV patients with MAC. This is
usually combined with or a fampin or a famb top. But just remember Microbacterium
avium complex MAC. When you want to treat MAC, you use a macrolide,
So remember that remember to treat MAC, you're going to use a mac
rolide. Community acquired pneumonia also is zithromycinchlorithromycin. So for both your typical organisms
like strap numo as well as your atypicals like microplasma pneumonia, macrolides are your
first line option, particularly azithomycin for your atypicals. Remember also gastroparesis with erythromycin
because erythromycin increases gastric motility. It's uses another option in addition to your meticlopromide.
And then the last one I think you should remember is your COPD bacterial
exascerbations. So in chronic bronchitis bacterial exascerbations, macro lines would generally be your
first line men to treat, and selected patients with severe COPD with frequent exascerbations,
macrolides can actually be used prophylactically to prevent exascerbations. Normally you're going to
see your zythromycin used in that case. As far as your adverse drug reactions,
there's a few QT prolongation, so all macrolides have been associated with QT
interval prolongation. Before giving one of these meds, make sure that the patient's
not at risk for trsades taking any other meds that can prolong the QT interval.
They do have some pretty prominent GI side effects, so a number of
different GI problems associated with ACO lines. Of course you're running the middle diarrhea
and abdominal pain we see in all the classes. But then you also have
a possibility of a patotoxicity with a zithro and a cute cholie static hepatitis,
particularly with arrhythromycin. And then finally they do have a cytochrome P for fifty
inhibition, so you have to look out for your drug to drug interactions other
drugs that they may be taking, like statins, warfare and digoxin. All
right, let's move on to our last class and wrap this up, and
that's going to be vencomycin. So venko myycin is an important one. I
covered a lot of classes, but not a lot of individual meds, but
venco comes up a lot, so I think it's important for you to know
this one. So venko myycin has really good grand positive coverage, specifically MRSA.
That's what you really need to know. So for your high old indications
for vanco, Venco's not actually used for a lot. It's mainly two things
that you need to know really well for Venco, and that's MRSA and c
DIFF. So MRSA, that's the big one. Venco and MRSA are synonymous.
As soon as you hear venko, be thinking MRSA. The other high
indication is c DIFF. And what's interesting about this is that we use po
venco to treat c DIFF, so we give venco by mouth. Vancomycin is
almost always given intravenously. We don't usually give venko po because it has a
really poor GI absorption, But the exception is when we're treating c DIFF.
We don't want vanco to get systemically absorbed, but we don't care about that.
We just want to kind of have it sit in the gut and because
that's where the C DIF infection is. So that's why we give venko po
for treating C DIFF. And this is really the only case that you'll give
venco micn po. Otherwise you're always for merca and everything else, you're giving
it intravenously. Now, as far as your adverse drug reactions, this is
another one where there's some high old things. So first thing is Redman syndrome.
It's not really called Redman syndrome anymore. That's what you're gonna hear it
called, but it's really officially called venkomycin induced infusion reaction associated with rash,
So let's just continue to call it Redman's syndrome. So this is something unique
with VANKO, and like most unique things, it's often tested on. Basically,
if you infuse vanco too quickly, you'll get this confluent or this blotchy
rash that covers the trunk, the extremities the head of the neck can be
pretty dramatic and all you avoid this just simply by infusing it slowly. A
couple other high yield things as far as your audiverse drug reactions. Autotoxicity,
this is more common in your older patients generally consider to be reversible in most
cases. And then nephrotoxicity, so Venco can be nephrotoxically into que kidney injury,
more common when it's co administered with other nephrotoxic agents like loop diuretics IVY,
contract IVY, contrast die amphotericin B, etc. So Venco is a
few high yield ADRs and indications. How do you remember the things that you
need to know for venco? So what I came up with is as soon
as you see vancomycin VA n coomycin, I want you to think of a
van, So vancomycin, think of a van and think of a van with
chrome hubcaps, like chrome rims, like those big pimped out chrome rims on
it. So I want you to think of vancomycin and think of a pimped
out van with chrome rims driving by. And chrome is spelled cr O,
M SO CRM. That stands for c DIFF. The R stands for Redman
syndrome and renal toxicity, the O and chrome stands for autotoxicity. And then
the M in chrome stands for MRSA, so MRCA covers. Remember again chrome
hubcaps. That's going to stand for C DIFF, Redman syndrome, renal toxicity,
autotoxicity, and then MRSA. All right, So one last time you
see vancomycin, think of a van, pimped out chrome rims, crom c
dif Redman syndrome, renal toxicity, autotoxicity, MRSA. That's vancomycin. That's
all you need to know. All right. Let's wrap it up with five
quick questions and we will be done with our antibiotics. So question one,
patient with penicillin allergy can safely be given Which class of betolactam antibiotics with no
risk of cross reactivity? Remember that's going to be as trion m your mono
back damn class, So that spatolactum has no cross reactivity with penicillin or cephalosporins,
except for the little exception I went over with ceftazidine that we discussed earlier.
Question two, A patient being treated from MERSA with ivannibiotics begins to develop
a red rash crosses head, neck, thorax and extremities as the IV anibiotic
is being administered. Which antibiotic is this patient likely receiving, So he's likely
receiving vencomycens or treating mersa. It's really only a number of meds to begin
with. Then we see he's developing a rash as the IV antibiotic is being
administered, which we know is normally caused by venkomycin. That's our Redman syndrome,
and that's if this medication is administered too quickly, they may develop that
confluent or blotchy rash spread throughout the body. Question three, which is the
only medication in the carbon penum class that does not cover pseudomonis. So carbon
penum class which men does not cover pseudomonis. That is going to be our
exception, our exception with an E that is e ORed apenem. So remember
in our carbon penum class, the only one that starts with an E.
That's our exception to the rule that all carbon panams cover pseudomonas. Urda panem
is that exception. It does not cover pseudomonas. Question for which medication is
first line to treat chlamydia, Rocky Mountain spotted fever and lime disease. That
was going to be doxy cycling. Don't forget you're sitting on a dock by
the sea, doxycycling eating clams, chlamydia, Rocky Mountain oysters, Rocky mounted
spotted fever with a squeeze of lime, lime disease. All right. Last
question, which fifth generation cephalosporin has coverage against MRSA. So remember that's going
to be septaroline aka se staroline. Star has five sides. Look up into
the stars. What's the closest planning you see mars, which is just MURSA
rearranged? All right, So that was your antibiotics. I hope that was
helpful. As always, thank you so much for the support. Good Luck
on your pants, your pandory rs, and good luck in PA school