Pharm, part 47: Immune Medications - Antibiotics - Cell Wall Inhibitors

by Cathy Parkes September 25, 2021 Updated: February 23, 2022 9 min read 1 Comment

Continuing our discussion of antibiotics, this article covers antibiotics that affect cell wall synthesis.

The Nursing Pharmacology video series follows along with our Pharmacology Second Edition Flashcards, which are intended to help RN and PN nursing students study for nursing school exams, including the ATI, HESI, and NCLEX.

Cool Chicken When you see this Cool Chicken, that indicates one of Cathy's silly mnemonics to help you remember. The Cool Chicken hints in these articles are just a taste of what's available across our Level Up RN Flashcards for nursing students!

What are cell wall inhibitors?

Cell wall biosynthesis inhibitors (CBIs) are among the most effective and extensively used classes of antibiotics.

Glycopeptide antibiotic: vancomycin

Cool Chicken The Red-man drives the van! He listens to music too loud in the van and doesn’t drink enough fluids, and now has hearing loss and kidney damage.

Vancomycin is a very important medication for nurses to know. Nurses working on a Med-Surg floor will be giving this medication frequently. In terms of the top five medications to know for nursing school and nursing practice, this medication definitely makes the top five.

Vancomycin is indicated for serious bacterial infections and antibiotic-associated C. diff (a germ (bacterium) that causes severe diarrhea and colitis).

Mode of action of vancomycin

Vancomycin’s mode of action is to destroy the bacterial cell wall, causing cell death.

Side effects of vancomycin

The side effects of vancomycin include ototoxicity (balance or hearing issues), nephrotoxicity (rapid deterioration of the liver and kidney functions), and an infusion reaction called Red Man Syndrome.

Red Man Syndrome is when the patient gets a red, itchy rash, which usually occurs if vancomycin is infused too quickly. Slowing down administration and/or giving the patient diphenhydramine or Benadryl usually helps to manage this and avoid Red Man Syndrome.

Vancomycin can also cause phlebitis (inflammation at the IV site). So if a patient has to be on vancomycin for an extended period, give the infusion of this medication through a PICC line.

Nursing care when administering vancomycin

Vancomycin has a low therapeutic index, which means there is a very narrow range of doses that are safe for the patient. So while it is important to give enough vancomycin to be effective, the amount at which vancomycin becomes toxic is very close to that minimum effective concentration. Doses may need to be adjusted depending on creatinine levels.

Infuse this medication over 1 hr (or more), that is, slowly.

Closely monitor the patient’s blood levels, as well as measuring vancomycin trough levels. Take the trough level right before the patient is about to get their next dose.

Note that it is also important to keep an eye on the drug's peak level (due to its potential toxicity).

Closely monitor the patient’s kidney function because of the side effect of nephrotoxicity.

Penicillin G

Penicillin G is used for bacterial infections.

Mode of action of penicillin G

Penicillin works by weakening the bacterial cell wall, causing cell death.

Side effects of penicillin G

Penicillin’s side effects include GI upset (e.g., diarrhea, nausea/vomiting). It also poses a threat for renal toxicity.

Penicillins are notorious for causing allergic reactions in patients, including dyspnea (shortness of breath, sometimes described as “air hunger”) and rash. Assess the patient for a history of allergic reactions to penicillin or cephalosporins before administration.

Another side effect of penicillins includes superinfection. Penicillin can wipe out the patient’s bacterial flora, which can give rise to a superinfection, such as C. diff. That means never administering an antibiotic unnecessarily, because of this risk for superinfection.

Remember to assess for allergies before administration, then monitor the patient for an allergic response after administration.

Aminopenicillin: amoxicillin (Moxatag)

Amoxicillin is another medication used for bacterial infections.

Mode of action of amoxicillin

Like penicillin G, amoxicillin works by weakening the bacterial cell wall, causing cell death.

Note that amoxicillin has a broader spectrum than penicillin G (it is prescribed more often).

Side effects of amoxicillin

Side effects of amoxicillin include diarrhea, superinfection (e.g., C. diff), and allergic reaction (dyspnea, rash).

As with penicillin G, assess for allergies before administration and monitor the patient for an allergic response afterward.

Extended release penicillin: piperacillin/tazobactam (Zosyn)

Extended release penicillin (piperacillin/tazobactam) is medication used for moderate to severe bacterial infections, including infections that are penicillin-resistant.

Mode of action of piperacillin/tazobactam

The mode of action for piperacillin/tazobactam, like penicillin, is to weaken the bacterial cell wall, causing cell death. Tazobactam inhibits beta-lactamase (an enzyme that destroys penicillin).

Side effects of piperacillin/tazobactam

Side effects of piperacillin include GI upset and superinfection (like C. Diff), as well as an allergic reaction (dyspnea, rash).

This medication, like vancomycin, can cause phlebitis (inflammation at the IV site).

It also carries the risk for hepatotoxicity (liver damage caused by exposure to drugs) as well as nephrotoxicity (which affects the kidneys as well as the liver).

Nursing care for patients receiving piperacillin/tazobactam

Do not give to patients with a history of allergies to penicillin or cephalosporin.

Monitor for allergic response.

Monitor bowel function.

Monitor liver and renal labs during therapy because of the potential side effects of hepatotoxicity and nephrotoxicity.

You can learn about liver and renal diagnostics using our Lab Values Study Guide & Flashcard Index, a list of lab values covered in our Lab Values Flashcards for nursing students, an easy reference guide.

Cephalosporins: cephalexin (Keflex), ceftriaxone (Rocephin), ceftazidime (Tazicef), cefepime (Maxipime)

Cool Chicken Cef sounds like Chef, reminding you to take it with food. Many start with cef.

Cephalosporins, which include medications such as cephalexin (Keflex), ceftriaxone (Rocephin), ceftazidime (Tazicef), and cefepime (Maxipime), are indicated for bacterial infections.

Mode of action of cephalosporins

This is another class of drug that works against the bacterial cell wall like penicillins.

Side effects of cephalosporins

Similar to the side effects of penicillins, the side effects of these medications include GI upset, the possibility for an allergic reaction, and superinfection (e.g., C. diff).

Before administration, assess the patient for a history of allergies to penicillins or cephalosporins.

Nursing care for patients receiving cephalosporins

Before therapy, advise the patient not to consume alcohol during therapy, as this could have an adverse effect or limit the medication’s efficacy.

Carbapenem: imipenem/cilastatin (Primaxin)

Carbapenems, which include imipenem cilistatin, are used for serious bacterial infections. This is a broad-spectrum antibiotic.

Mode of action of carbapenem

This is another class of drug that, like penicillins, works against the bacterial cell wall, causing cell death.

Side effects of carbapenem

Its side effects include GI upset, rash, superinfection (e.g., C. diff), and the possibility for seizures.

Nursing care for patients receiving carbapenems

Assess the patient for a history of allergic response to medications such as penicillin or cephalosporins (or carbapenems; people who have a history of reaction to penicillins or cephalosporins may react to carbapenems as well).


Full Transcript

Hi, I'm Cathy with Level Up RN. In this video, I am going to continue my coverage of antibiotics. In our last video, we talked about antibiotics that affect protein synthesis. In this video, we are going to talk about antibiotics that affect cell wall synthesis. And at the end of the video, I'm going to give you guys a little quiz to test your knowledge of some of the key facts I'll be covering in this video. So definitely stay tuned for that. And if you have our pharmacology flashcards, definitely pull those out so you can follow along. These are available on leveluprn.com.

The first medication I'm going to cover in this video is vancomycin, and this is a very important medication for you to know as a nurse. So if you're going to be working on a medsurg floor, you're going to be giving this medication frequently. And in terms of top five medications, you have to know four nursing school and a nursing practice. I definitely would include this medication in the top five.

So vancomycin is used for serious bacterial infections. It destroys the bacterial cell wall.

It has several serious side effects, which include autotoxicity, nephrotoxicity and an infusion reaction called Red Man Syndrome. This is where the patient gets a red, itchy rash. Usually occurs if we infuse vancomycin too quickly. So if we slow it down and/or give them diphenhydramine or Benadryl, we can usually manage this and not have them get Red Man Syndrome. Vancomycin can also cause phlebitis, so inflammation at the IV site. So if a patient has to be on vancomycin for a while, we usually have them get a pick line, a central line and give the infusion of vancomycin through that pick line.

Key points with this medication. Vancomycin has a low therapeutic index, meaning there's a very narrow range of doses that are safe for the patient. So we need enough vancomycin to be effective. But the amount at which vancomycin is toxic is very close to that minimum effective concentration.

So we're going to be closely monitoring the patient's blood levels and we're going to need to get their trough levels of vancomycin. So we would pull that trough level right before the patient is about to get their next dose. We're also going to want to closely monitor the patient's kidney function because of the side effect of nephrotoxicity.

So our little cool chicken hint here on the card to help you remember this medication is the red man drives the van. And this man is driving in the van. He's listening to music too loudly, which is causing hearing damage, and he's not drinking enough water, which is causing kidney damage. So this little story is intended to help you remember that vancomycin can cause Red Man syndrome, autotoxicity and kidney toxicity.

Next up, we have our penicillin, which include penicillin G and amoxicillin.

These medications are used for bacterial infections, and they work against the bacterial cell wall.

Side effects include GI upset, so nausea and vomiting and diarrhea. Also, penicillins are notorious for causing an allergic reaction in many patients. So you definitely need to assess your patient for a history of allergic reactions to penicillin or cephalosporins before administration. Another side effect of penicillins includes a super infection. So when we give the patient an antibiotic such as penicillin, it kind of nukes and paves their bacterial flora, which can give rise to these super infections, such as C diff. So we never want our patient to take antibiotics unnecessarily because of this risk for super infection.

So with penicillins, again, you're going to assess for allergies before administration.

And then after administration, you're going to monitor the patient for an allergic response.

Then we have an extended release penicillin, which is piperacillin tazobatam. And this medication would be used for moderate to severe bacterial infections, including infections that are penicillin resistant.

Side effects again include GI upset super infection. This medication can also cause phlebitis, so inflammation at the IV site. It also carries the risk for hepatotoxicity as well as nephrotoxicity.

So in addition to assessing our patient for a history of allergies to penicillins or cephalosporins, we're also going to want to monitor our patient's liver and renal function during therapy because of that side effect of hepatotoxicity and nephrotoxicity.

Next, we have our cephalosporins, which include medications such as cephalexin, ceftriaxone and cefepime. So they all start with that cef.

We would use these medications for bacterial infections, and they work against the bacterial wall just like penicillins.

Side effects include GI upset, possibility for an allergic reaction and super infections. So very similar side effects to penicillins. So again, you're going to want to assess your patient for a history of allergies to penicillins or cephalosporins.

Before therapy, you also want to advise your patient to not consume alcohol during therapy.

Then the last drug class we're going to cover in this video are carbapenems, which includes imipenem cilistatin.

So this medication is used for serious bacterial infections. This is a broad spectrum antibiotic.

Side effects include GI upset, rash, super infection and the possibility for seizures. So again, with this medication, you're going to want to assess for a history of allergic response to medications such as penicillin or cephalosporins or these carbapenems. Because sometimes people who have had a history of reaction to penicillins or cephalosporins may react to carbapenems as well.

All right, time for a quiz. I have three questions for you. First question, what antibiotic can cause autotoxicity, nephrotoxicity and Red Man syndrome? The answer is vancomycin. Question number two, if your patient has a penicillin allergy, they may also have an allergic response to what medication class? It's actually two possible answers here. One is cephalosporins, the other is carbapenems. Question number three. Trough levels will need to be monitored when your patient is on vancomycin. True or false? The answer is true because vancomycin has a very low therapeutic index, so we're going to be closely monitoring the patient's blood levels to get the dosing just right.

Okay, that's it. I hope this video has been super helpful for you. If you've got value out of it, definitely leave me a comment. I would love to hear from you. Next, we have our cephalosporins, which include medications such as cephalexin ceftriaxone and cefepime, so they all start with that cef. We would use these medications for bacterial infections. Next, we have our cephalosporins, which include medications such as cephalexin, cepha-- sorry.


1 Response

Pamela
Pamela

February 21, 2022

Very helpful! thank you!

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