Beta-Lactam Antibiotics: Cephalosporins (Nursing)

00:01 Hi, and welcome to our video on Beta-lactam antibiotics and vancomycin.

00:07 So we want to start right out letting you know that cephalosporins, carbapenems, and monobactams are beta-lactam antibiotics.

00:15 Vancomycin is a separate 1 that I wanted to group together with these three beta-lactam antibiotics.

00:22 So let's open up with a question.

00:24 Why are they called Beta-Lactam Antibiotics? So, pause and just write the answer in the margin of your notes.

00:36 Now, if you've seen our other video on penicillins, you know, they're called beta-lactam antibiotics because all these antibiotics share a common chemical structure -- a beta-lactam ring.

00:48 And there's 4 major subclasses of beta-lactam antibiotics.

00:52 We talked about the penicillins in a separate video.

00:55 But now we're going to talk about the cephalosporins, the carbapenems, and the monobactams, and we'll wrap up with vancomycin a little later.

01:02 Remember, it is not a beta-lactam ring antibiotic, but we just included it with this group.

01:08 Now, we're going to take a look at 5 generations of cephalosporins.

01:12 The first through the fifth generation. Now, they get better with age.

01:17 I'm going to walk through each generation, 1 at a time, and they're named first, second, third, and so on, because that's the order they were discovered.

01:24 So, first generations are the oldest cephalosporin.

01:28 Fifth generations are the newest cephalosporin.

01:31 I'm going to, kind of, give you an overview at the end, but let's take a look at these.

01:35 The first generation of cephalosporins, they go after gram-positive bacteria.

01:41 They really don't do much for gram-negative.

01:43 Now, I want you to look at the third column. This is where things get really interesting with the cephalosporins.

01:49 Now, you see we have a note there. It says it's not effective concentrations in CSF.

01:54 That stands for cerebral spinal fluid.

01:58 We put that note there because this first generation can't get into the central nervous system.

02:03 Remember, the cerebral spinal fluid is what lubricates that central nervous system, and the first generations can't cross over to that.

02:11 So if we can't get a strong concentration in the CSF, the cerebral spinal fluid, then we're going to not be able to treat an infection in the central nervous system.

02:21 Now, second generation gets a little bit better about gram-negative, but look at that third column.

02:28 Right. Second generations are not able to get an effective concentration in your CSF, your cerebral spinal fluid, meaning we can't use these to treat infections in the central nervous system.

02:42 It's also not active against Pseudomonas aeruginosa.

02:46 Third generation is highly effective against gram-negative bacteria.

02:51 Okay, so first was not very good.

02:53 Second, got a little bit better, but third is where it really starts to get good.

02:58 This is also the first generation that can actually cross into the cerebral spinal fluid.

03:03 So, these were the first types of cephalosporins that we were able to use for types of central nervous system infections, like meningitis.

03:13 So these were the drugs of choice for meningitis that are caused by gram-negative bacilli.

03:19 So, now it's starting to become a little clearer when I said as the new drugs were discovered, they got better.

03:25 They got better at dealing with gram-negative, and they got better at crossing into the central nervous system.

03:31 Remember, first and second do not cross into the central nervous system.

03:35 Third is the one that's, so far, the best against gram-negative bacteria, and it does cross into the CNS.

03:43 Now, the fourth generation we use for healthcare and hospital-associated pneumonias.

03:48 That means they came in for our care, and we gave them a pneumonia.

03:52 So the fourth generation has an effective concentration in the cerebral spinal fluid too; cool. That means we can also use it get across that barrier into the cerebral spinal fluid. But remember, the third generation is still our first choice for meningitis.

04:08 So, from the third generation on down, these antibiotics can actually cross into the central nervous system.

04:16 Remember, your CNS is protected by that blood-brain barrier.

04:20 Got those super tight junctions so that the bugs, or the drugs actually have to go through the cell to get there.

04:29 Only the third and fourth generation of cephalosporins can actually accomplish that.

04:34 The fifth generation is the coolest of them all.

04:38 It is the only 1 of the generations of cephalosporins that can be used to treat MRSA.

04:44 Now, we've talked about MRSA before, but it stands for methicillin-resistant Staphylococcus aureus.

04:51 So that's a staph infection that we used to be able to treat with methicillin, but now it is resistant.

04:58 So that the fifth generation can do that is over-the-top cool.

05:02 Now, it can also get into your cerebral spinal fluid, but remember, third generation is our favorite, right now, for meningitis.

05:09 What's cool about the fifth generation is that it can be used to treat MRSA, which is a resilient and kind of nasty bug.

05:18 So, when you're thinking about the different generations of the cephalosporin, they just simply get better with age.

05:25 In the third generation, again, we can cross over to cerebral spinal fluid, fourth, and fifth. And the unique thing about fifth is that we can use it to treat MRSA.

05:37 Now, the adverse effects for cephalosporins are going to look familiar to you, and compared to the other antibiotics that we discuss.

05:43 So, allergic reactions and possible anaphy- laxis are some of the top reactions.

05:49 However, there are some that are unique to cephalosporins.

05:53 2 of the cephalosporins, cefotetan and ceftriaxone can interfere with a vitamin K metabolism, and that puts your patient at risk for bleeding.

06:03 Okay, that's a really unusual side effect for an antibiotic, so make sure you star that one in your notes for these 2 particular cephalosporins that can cause bleeding for your patients because it interferes with vitamin K metabolism.

06:18 Remember, vitamin K metabolism is really important, and we'll talk about that more when we get with warfarin.

06:25 That's another drug that we use as a blood thinner.

06:28 So, we have, A, for allergic reaction or a possible anaphylaxis, then you've got, B, for bleeding, and C for thrombophlebitis, that means clots.

06:40 So, if we have someone who ends up with a phlebitis, that puts someone at a risk for clots if it's IV infused.

06:47 So, for the cephalosporins that are IV infused, watch for the possibility of thrombophlebitis, which could produce a clot for your patient.

06:54 Now, this is a rare side effect, but hemolytic anemia can be a possible adverse effect for a cephalosporin.

07:02 Hemolytic means -- that's -- breaks open those red blood cells.

07:07 It's very rare, but we just want to make you aware that it is a possibility.

07:12 Now, cephalosporins and alcohol do not mix.

07:16 We also talked about this in our Adverse Effects video, but we want to hit it again in this one, because if cefotetan or ceftriaxone are concurrent with alcohol, you have that disulfiram effect.

07:29 Remember that disulfiram is a drug that people who are trying to get over the use of alcohol, the abuse of alcohol, take it on a daily basis, because if they mix the drug and alcohol, they have a really nasty effect.

07:43 End up with severe flushing, and nausea, vomiting, possibly even tachycardia and a low blood pressure.

07:50 That's because the combination of the cephalosporin and alcohol will cause acetaldehyde to accumulate in your blood.

07:58 So, you want to make sure that you educate your patients that they should not drink alcohol when they're on a cephalosporin.