hey everyone this lesson is on the antibiotics known as cephalosporins in the system we talk about what cephalosporins are also going to talk about all the generations as cephalosporins including the differences between the generations and we're going to talk about the bacteria and infections that the cephalosporins treat so cephalosporins are a class of beta-lactam antibiotics so beta-lactam because they have a beta-lactam ring all of these cephalosporin antibiotic names start with the prefix SEF or SEF so c EF or c e ph so that's how you can determine or identify the cephalosporin antibiotics so the mechanism of action of the cephalosporins is similar to other beta-lactam antibiotics they are back to your recital through their ability to inhibit cell wall synthesis by binding to penicillin binding proteins on bacteria so I'm going to quickly talk about adverse effects and contraindications to cephalosporins now because we're gonna talk about all the different generations of cephalosporins in the next few slides so adverse effects of cephalosporins in general include the following skin rashes pure itis and stevens-johnson syndrome are some of the possible adverse effects some of the more common of adverse effects include nausea vomiting and diarrhea we may also see a risk of seizures especially with the cephalosporin cefepime nephrotoxicity is also a possible adverse effect of cephalosporins and we may also see allergic reactions the contraindications to using cephalosporins include the following includes hypersensitivity reactions to cephalosporins or other beta-lactam antibiotics so if you're alerted to a penicillin you may have cross reactivity to cephalosporins so it may be a contraindication to their use so again hypersensitivity to cephalosporins or other beta-lactam antibiotics is the contraindications here that are use so we'll begin by talking about first generation cephalosporins first generation cephalosporins include cefalexin which is also known as Catholics in cefalexin is a pill form it is a PL form taken by mouth the other first generation cephalosporin is cefazolin cefazolin is also known as ancef and it is the essentially equivalent of cephalexin in an IV or IM form so again cephalexin is by mouth pill form cefazolin is IV or IM form so the first generation cephalosporins have good bacterial coverage for gram positive bacteria especially aerobic cocci they also have coverage for group a group b streptococci and veerudu and strep as well as methicillin sensitive staph aureus or MSS a but they do not have activity against mmrsa or Enterococcus now they do have some coverage for gram-negative bacteria including eco like Proteus and Klebsiella but they have inadequate activity against Hamas influenza or Moraxella catarrhalis they do have some anaerobic coverage but no activity against Bacteroides fragilis so infections treated with set first generation cephalosporins include the following they include uncomplicated community-acquired skin and soft-tissue infections so infections that you're not worried about having risk for mrs a uncomplicated UTIs because they cover some of these gram-negative rods and surgical wound prophylaxis to prophylaxis against common skin infections with grande positive bacteria now the second generation cephalosporins include cefotetan cefuroxime SEF Brazil in cefoxitin they cover gram positive very similarly to the first generation cephalosporins they covered aerobic cocci but they have slightly less activity against the staphylococci and they cover generally the non enterococci streptococci so they have no coverage for mrs a or enterococci similar to the first generation cephalosporins however with regards to gram-negative coverage they again cover a robes but they have increased activity against gram-negative bacteria compared to the first generation cephalosporins they cover Moraxella catarrhalis unlike the first generations of sports and they cover Neisseria meningitidis with regards to amazos influenza most of them don't cover this bacteria except for sefirot seem so sefirot seem is special in that it covers age flu and some of the second generation cephalosporins have increased coverage to include some oral anaerobes particularly cefoxitin in Sefo ten so cefoxitin cefotetan are also known as sessom Ison's you can take a seven license as like a subcategory in second generation cephalosporins and these are the cephalosporins that have increased coverage of oral anaerobes like Bacteroides fragilis so infections that second generation cephalosporins treat include the following respiratory tract infections that are community-acquired uncomplicated urinary tract infections or UTIs they can also be used for surgical wound prophylaxis pneumococcal pneumonia and mixed aerobic and anaerobic infections especially with the seven license like cefoxitin in cefotetan now the third-generation cephalosporins include ceftriaxone cefotaxime cefixime Sefton ear and ceftazidime so a larger group in this category third-generation cephalosporins have the ability to cross the blood-brain barrier unlike the other generations of cephalosporins we've talked about previously they are generally used for in hospital patients a lot of them are parental so they're given by IV grant positive coverage is generally less than previous generation so they have less activity against gram-positive organisms they have no activity against the following organisms like enterococci Listeria Acinetobacter and mr sa but they do have some activity against MSSA so very similar activity against gram-positive organisms like the previous two generations but slightly less with regards to gram-negative coverage they actually have increased activity against Enterobacter eca increased activity against gram-negative bacteria in general but they have no activity against Pseudomonas but there is a caveat with this cept as a team one of the third-generation cephalosporins actually does treat Pseudomonas infection so SEPTA's Adeem covers Pseudomonas but the other third-generation cephalosporins do not and they are active against oral anaerobes like Bacteroides fragilis now a quick note here is that if a bacteria is resistant to third-generation cephalosporins they are ESBL bacteria or extended spectrum beta-lactamase bacteria so you may hear about ESBL bacteria that means that they are resistant to third-generation cephalosporins now with regards to infections treated by third-generation cephalosporins infections include gram-negative meningitis pneumococcal infections and a wide variety of hospital-acquired and complicated community acquired infections like respiratory tract infections blood infections skin and soft-tissue infections and others as well so you'll see third-generation cephalosporins used a lot they have good coverage for gram-negative bacteria you may see ceftriaxone used frequently especially in hospital patients so these are very important antibiotics to remember and recognize but again they don't have activity against Pseudomonas except for Sept azzedine and another quick note in Sept azzedine except azzedine is a third-generation cephalosporin but think about it as a 3.5 generation cephalosporin it has similar activity against bacteria like third-generation cephalosporins but also has activity against Pseudomonas so that's why it makes it special now with regard to the fortune raishin cephalosporins these include cefepime and SEF Pyron these also cross the blood-brain barrier they are used in in hospital patients with regards to gram positive bacteria they have increased activity compared to the third generation of cephalosporins they cover strep pneumoniae and Group A and Group B streptococci with regards to gram-negative coverage they have a broad spectrum of activity they are similar to the third-generation cephalosporins but they also have activity against Pseudomonas and they also have improved activity against what we call space organisms I didn't talk about these previously but space organisms are the following Serratia Proteus Senado bacter citrobacter and enterobacter generally speaking when you see these organisms you don't use cephalosporins third-generation cephalosporins don't work well against these organisms but fortune raising cephalosporins do have increased activity against some of these organisms like Serratia Proteus citrobacter and enterobacter but not Acinetobacter so that's just a quick note on space organisms and the fourth generation cephalosporins interestingly don't have activity against Bacteroides fragilis so we've seen in the last couple generations that we've had increasing activity against an aerobic coverage like Bacteroides fragilis but with Fortuner asa cephalosporins we don't have activity against this bacteria so with regard to infections treated with set for generation cephalosporins we want to think about Pseudomonas EXO this is very important if you're thinking that a patient may have a Pseudomonas infection you can use this fourth generation cephalosporin but generally speaking these are not used gram-negative meningitis may also be a infection that a fortune oration cephalosporin is used for in antibiotic resistant infections in general so these antibiotics have a broader spectrum so we generally reserved their use for infections with antibiotic resistant bacteria I want to speak briefly on fifth generation cephalosporins fifth generation cephalosporins include SEF terylene SEF terylene is active against mr si unlike the previous generations we talked about earlier that don't have any activity against mr si SEF terylene does but interestingly it has less activity against gram negative organisms it has no activity against Pseudomonas and is less active against space organisms unlike the fourth generation cephalosporins so here is a summary overview of the first two fourth generations of cephalosporins so with regards to gram-positive and gram-negative coverage first generation cephalosporins have increased gram-positive coverage but little very little gram-negative coverage as they move along up the generations the second generation cephalosporins have slightly more than gram-negative coverage and slightly less gram-positive coverage with regards to the third-generation cephalosporins like ceftriaxone they rapidly gain gram-negative coverage but lose some of their gram-positive coverage and with regards to the fourth generation cephalosporins they have even better gram-negative coverage so you can get some of those space organisms and they have some slightly increased gram-positive coverage as well and off the chart that is not included here the fifth generation cephalosporin terylene has increased gram-positive coverage but decreased gram-negative coverage so that is a broad overview summary of the generations of cephalosporins so if you want to learn more about other antibiotics i would suggest checking out my pharmacology playlist you can check out my fluoroquinolone lesson to look at all the different generations of fluoroquinolones as well and if you haven't already please consider liking subscribing and clicking the notification bubble up support the channel and as always thank you so much for watching and I hope to see you next time