Antibiotics - Carbapenems and monobactams: Nursing pharmacology

Carbapenems and monobactams are beta-lactam antibiotics, which means that they have a characteristic beta-lactam ring in their structure.

However, due to their widespread use, some bacteria have acquired resistance to many beta-lactams by developing enzymes called beta-lactamases, which latches on to the beta-lactam ring and degrades the antibiotic.

For this reason, carbapenems and monobactams have a slight modification in their beta-lactam ring structure, which makes them less susceptible to beta-lactamases.

Now, carbapenems can be used to treat serious infections, such as complicated appendicitis, peritonitis, soft-tissue infections, bacterial meningitis, as well as gynecological infections, pyelonephritis, and bacteremia.

Carbapenems have a wide range of action against gram-positive bacteria like methicillin-sensitive Staphylococcus aureus, Streptococcus pneumoniae, and group A beta-hemolytic streptococci; and gram-negative bacteria like Enterococcus faecalis, Pseudomonas aeruginosa, Klebsiella spp, Neisseria spp, and Acinetobacter spp.

On the other hand, monobactams are only useful in the treatment of gram-negative bacterial species, and are primarily used to treat clients with cystic fibrosis who have pulmonary Pseudomonas aeruginosa infections.Starting with carbapenems, the most commonly used ones include doripenem, ertapenem, meropenem, as well as meropenem-vaborbactam, a combination of meropenem and vaborbactam, a beta-lactamase inhibitor, which further increases the spectrum of activity, and imipenem-cilastatin, a combination of carbapenem and the dipeptidase inhibitor cilastatin which prevents imipenem from being broken down, prolonging its antibacterial effect.

Now, all of the carbapenems are administered intravenously, and ertapenem can also be given intramuscularly. Moving on to monobactams, the only medication in this group is aztreonam, which is only given via inhalation.

Once administered, carbapenems and monobactams work by binding to and inhibiting a bacterial enzyme called DD-transpeptidase, or penicillin-binding proteins, or PBPs for short, which bacteria need to build their cell walls.

As a result, carbapenems and monobactams act by inhibiting bacterial cell wall synthesis, which ultimately kills the bacteria.

Common side effects of carbapenems and monobactams include gastrointestinal disturbances, like nausea, vomiting, and hypersensitivity reactions.

These medications can also disrupt the normal bacterial flora, increasing the risk of superinfections like Clostridioides difficile infection, as well as oral and vaginal candidiasis.

Clients taking these medications may also experience central nervous system disturbances like headaches, confusion, and even seizures.

Some clients may present with serious hypersensitivity reactions, such as Stevens-Johnson syndrome, toxic epidermal necrolysis, angioedema, and even anaphylaxis.

Finally, when given via injection, these medications can cause injection site reactions like pain, redness, and even thrombophlebitis; while aztreonam administered via inhalation can cause cough, bronchospasm, and sore throat.Now, carbapenems and monobactams are contraindicated in clients allergic to any beta-lactam antibiotic due to the risk of cross-reactivity between the different classes.

Carbapenems and monobactams should be used with caution in clients with a history of seizures and during pregnancy and breastfeeding.

Additional precautions should be taken in clients with renal disease. With respect to drug interactions, carbapenems decrease the effects of the antiepileptic medication valproate, which can put clients at increased risk of seizures.

Additionally, the use of imipenem-cilastatin with ganciclovir and cyclosporine can also precipitate seizures. Lastly, carbapenems should not be combined with probenecid, as it can lead to carbapenem toxicity.

Now, when a client diagnosed with gram-negative bacteremia is prescribed intravenous imipenem-cilastatin, begin by assessing their vital signs and symptoms, such as fever, malaise, and chills.

In addition, review their most recent laboratory test results, including renal and hepatic function tests, CBC, blood culture and sensitivity, and urinalysis and urine culture; as well as diagnostic test results, including chest X-ray.Moving on to client education, explain to your client how imipenem-cilastatin helps eliminate the bacteria in their blood.

Then, let them know that the medication will be administered intravenously, and prompt them to inform you if they experience any pain or discomfort at the infusion site; or if during the infusion they feel nausea, itchiness, tightness in their chest or throat, or have difficulty breathing or swallowing.

During administration, be sure to closely monitor your client. If you notice signs of phlebitis, such as redness and swelling, stop the infusion immediately and restart therapy at a different site.

If nausea or vomiting occur, slow the infusion, contact the healthcare provider for an antiemetic, and provide comfort measures, such as cool compresses placed on the forehead, positioning for comfort, and encouraging deep breathing and relaxation.

Lastly, stop the infusion and notify the healthcare provider immediately if you suspect your client is having a hypersensitivity reaction, which could present as dyspnea, wheezing, or swelling of the face, mouth, or tongue; or if your client develops signs of Clostridioides difficile infection, such as loose, watery, or bloody stools, and collect a stool sample to send to the lab for analysis, as ordered.

Finally, throughout therapy, be sure to monitor your client for the development of side effects, and evaluate for the desired therapeutic effect, which is resolution of the signs and symptoms of bacteremia.All right, as a quick recap… Carbapenems and monobactams are antibiotics that can be used to treat serious infections, such as complicated appendicitis, peritonitis, soft-tissue infections, and bacteremia.

Side effects include hypersensitivity reactions, phlebitis at the infusion site, superinfection, and gastrointestinal or central nervous system disturbances.

Nursing considerations include performing a baseline assessment, close monitoring for side effects, intervening appropriately, and evaluating the desired therapeutic effect.

Client education is focused on understanding what to expect during therapy, as well as symptoms that should be reported.

performing a baseline assessment, close monitoring for side effects, intervening appropriately and evaluating the desired.

Therapeutic effect client education is focused on understanding what to expect during therapy as well as symptoms.