12.8 Monobactams
Like penicillins, cephalosporins, and carbapenems, monobactams also have a beta-lactam ring structure. The only med in this category is aztreonam.
Indications for Use
Monobactams are narrow-spectrum antibacterial medications that are used primarily to treat gram-negative bacteria such as Pseudomonas aeruginosa.
Mechanism of Action
Monobactams are bactericidal and work to inhibit bacterial cell wall synthesis. They have a structure that is highly resistant to beta-lactamases. They inhibit the synthesis of peptidoglycan layer of gram-positive bacterial cell walls (Vallerand & Sanoski, 2024).
Nursing Considerations
Aztreonam is only given IV or IM.
Clients taking monobactams may experience adverse effects similar to other beta-lactam medications, so nurses should monitor for GI symptoms, skin sensitivities, and coagulation abnormalities.
Across the Lifespan: Monobactams are considered safe for use in pediatrics. Some dose adjustments are required based on renal dysfunction in older adults. Monobactams can be given during pregnancy if the client is allergic to other, more preferred, antibiotics.
Client Teaching
- Monitor for signs of superinfection and report any occurrence to the provider. If the client experiences fever and bloody diarrhea, they should contact the provider immediately.
- Monitor for rash, hives or swelling and report any occurrence.
Monobactams Medication Card
Now let’s take a closer look at the medication card for Monobactams Daily Med, 2019: UpToDate, 2021). Because information about medication is constantly changing, nurses should always consult evidence-based resources to review current recommendations before administering specific medication.
To help with comparing the medications and to learn important considerations for each medication, refer to the: Chapter 12 Antimicrobials Medication Cards
Medication Card: Monobactams
Prototypes: azteronam
Mechanism: Bactericidal. Narrow-spectrum.
Indications
- used primarily to treat gram-negative bacteria such as Pseudomonas aeruginosa.
Administration
- IM, IV, or via inhalation
- Peak: 60 minutes via IM
- ½ life: 1.5-2 hours with normal renal function
Contraindications
- Check for allergies to any beta lactams – penicillin, cephalosporins, or carbapenems
- Impaired renal function
Side Effects
- hematologic neutropenia
- increased serum liver enzymes
- GI: GI upset, N/V, diarrhea, dehydration, electrolyte imbalance
- Skin sensitivities
- Coagulation abnormalities
- Superinfection
Contraindications
- Check for allergies to any beta lactams – penicillin, cephalosporins, or carbapenems
- Impaired renal function
Nursing Considerations
- Monitor renal and liver function
- Monitor for signs of anaphylaxis during first dose
- Monitor skin (rash), bowels (diarrhea)
- Monitor for systemic signs of infection: elevated WBC count, fever, culture results. Monitor site of infection for improvement.
Clinical Reasoning and Decision-Making Activity
Using the above information, consider the following clinical scenario question:
A client with cystic fibrosis is diagnosed with ventilator-associated pneumonia and is prescribed Aztreonam 1 gm IV daily for a suspected Pseudomonas aeruginosa infection. The nurse reviews the culture results that just arrived and notices that the results indicate the infection is caused by Methicillin-resistant Staphylococcus aureus. Will this medication be effective against this bacteria? What is the nurse’s next best response?
Note: Answers to the Clinical Reasoning Activities and Critical Thinking questions can be found in the Chapter 12: Antimicrobial Medications answer key – Fundamentals of Nursing Pharmacology – 2nd Canadian Edition section at the end of the book.
References
Daily Med, https://dailymed.nlm.nih.gov/dailymed/index.cfm, used for hyperlinked medications in this module. Retrieved June 27, 2019. ↵
UpToDate (2021). Aztreonam. https://www.uptodate.com/contents/search ↵
Vallerand, A. & Sanoski, C. (2024). Davis’s Canadian drug guide for nurses (19th ed.). F.A. Davis Company: Canada
