Carbapenems: Uses, common brands, and safety info

Carbapenems are part of a class of antibiotics called beta-lactam antibiotics. Carbapenems have a broad spectrum of activity and are often used to treat severe infections, including multi-drug-resistant serious infections caused by bacteria. Beta-lactam antibiotics are named this way because part of their structure includes a beta-lactam ring. Beta-lactam antibiotics include:

• Carbapenems

• Cephalosporins (such as cephalexin)

• Monobactams (such as aztreonam)

• Penicillins (such as amoxicillin)

Carbapenem antibiotics are prescription medications that are approved by the U.S. Food and Drug Administration (FDA). Carbapenems, like other antimicrobial agents, are only effective against infectious diseases caused by bacteria (bacterial infections). They do not work against viral infections such as the flu, common cold, or COVID-19.

This article will focus on carbapenems, including their brand names, uses, side effects, and safety information. The table below lists carbapenem drugs.

Other carbapenems:

• Thienamycin was the first carbapenem developed, but it was chemically unstable and is not available as a prescription drug. (Carbapenems are derivatives of thienamycin.)

• Doripenem was a carbapenem antibiotic that is no longer available for use. Doribax (doripenem) was removed from the market sometime after 2014 when the FDA added safety warnings to its labeling.

• Primaxin* (imipenem/cilastatin)

• Recarbrio** (imipenem/cilastatin/relebactam)

• Vabomere*** (meropenem/vaborbactam)

*Primaxin contains imipenem (antibacterial) and cilastatin (not an antibiotic, but a renal dehydropeptidase inhibitor that protects the degradation of imipenem).

**Recarbrio contains imipenem, cilastatin, and relebactam (not an antibiotic, but a beta-lactamase inhibitor—β-lactamase inhibitor—that protects the degradation of imipenem).

***Vabomere contains meropenem (antibacterial) and vaborbactam (a beta-lactamase inhibitor).

What are carbapenems?

Carbapenems are a group of drugs in the beta-lactam antibiotic class (β-lactam antibiotics). Other medications in the beta-lactam class include popular antibiotics such as Keflex (cephalexin), amoxicillin, and Augmentin. 

Carbapenems are known as broad-spectrum antibiotics because they have a wide spectrum of activity and work on many types of bacteria, even bacteria resistant to other antibiotics. Unlike other beta-lactam drugs, which are commonly taken by mouth, carbapenems are given by injection. Invanz can be given by intravenous or intramuscular route. Sometimes carbapenems are given with other antibiotics, such as aminoglycosides. 

To lower antibiotic resistance, carbapenems should only be used to treat or prevent infections proven or strongly suspected to be caused by susceptible bacteria. Culture and susceptibility information, when available, should be considered when choosing an antibiotic. 

How do carbapenems work?

Carbapenem antibiotics work by attaching to penicillin-binding proteins (PBPs) and preventing bacteria from forming a cell wall. Preventing cell wall synthesis makes the bacteria die. Because carbapenem antibiotics are similar in structure to penicillin antibiotics, people who are allergic to penicillin antibiotics may be allergic to carbapenems. 

What are carbapenems used for?

Carbapenems can be used for various Gram-positive and Gram-negative aerobic (aerobes)  and anaerobic bacteria (anaerobes). Refer to each monograph for specific indications. General indications for carbapenems include:

• Complicatedintra-abdominalinfections 

• Complicated skin and skin structure infections 

• Bone and joint infections

• Endocarditis 

• Community-acquired pneumonia 

• Lower respiratory tract infections

• Complicated urinary tract infections, including pyelonephritis

• Acute pelvic infections/gynecologic infections

• Bacterial meningitis

• Bacterial septicemia

• Hospital-acquired bacterial pneumonia 

• Ventilator-associated bacterial pneumonia 

• Prevention of surgical site infection after elective colorectal surgery

Types of carbapenems 

Group 1 carbapenem

Invanz (ertapenem) is known as a group 1 carbapenem. It is the only group 1 carbapenem and has a broad spectrum of activity against pathogens, including:

• Enterobacteriaceae ( Enterobacter)

• Escherichia coli ( E. coli)

• Haemophilus

• Moraxella

• Neisseria

• Klebsiella pneumoniae

• Staphylococcus aureus (methicillin-susceptible)

• Streptococcus pneumoniae ( penicillin-susceptible or penicillin-resistant) 

• Streptococcus pyogenes

• Viridans group streptococci

• Bacteroides

• Clostridium difficile

• Eubacterium

• Fusobacterium

• Peptostreptococcus

Invanz has limited activity against certain Gram-negative bacilli such as Pseudomonas aeruginosa (P. aeruginosa). This medication is more suitable for community-acquired infections, meaning an infection acquired in the community, outside of a healthcare or hospital setting. 

Group 2 carbapenems 

Carbapenems that contain imipenem (Primaxin and Recarbrio) or meropenem (Merrem and Vabomere) are known as group 2 carbapenems. They also have a broad spectrum of activity against pathogens, including:

• Acinetobacter

• Enterobacteriaceae

• Escherichia coli ( E. coli)

• Haemophilus

• Klebsiella pneumoniae

• Moraxella

• Neisseria

• Pseudomonas aeruginosa

• Listeria

• Staphylococcus aureus 

  (methicillin-susceptible)

• Streptococcus pneumoniae 

  (penicillin-susceptible and penicillin-resistant)

• Streptococcus pyogenes

• Viridans group streptococci

• Bacteroides

• Clostridium difficile

• Eubacterium

• Fusobacterium

• Peptostreptococcus

• Propionibacterium

Group 2 carbapenems have better coverage of Gram-negative bacteria, or Gram-negative organisms. They are especially useful in treating nosocomial infections, which are infections acquired in a healthcare or hospital setting. 

Who can take carbapenems?

Only the healthcare provider can determine if a carbapenem is safe and appropriate for use. Before a carbapenem is ordered, the healthcare provider will review medical history and medical conditions, and other medications the patient is taking to ensure that the carbapenem will be safe and appropriate to use. 

Men 

Men can take a carbapenem, provided they have a bacterial infection that is proven or strongly suspected to be susceptible to a carbapenem and that the patient does not have any contraindications for use. 

Women 

Women who are not pregnant or breastfeeding can take a carbapenem if they have a bacterial infection that is proven or suspected to be susceptible to a carbapenem. The patient also must not have any contraindications for the use of a carbapenem. 

Women who are pregnant or breastfeeding

Women who are pregnant or suspect they are pregnant, or breastfeeding, should consult their healthcare provider before use of a carbapenem. With Invanz and meropenem, there is not enough clinical trial data on pregnant women. In Primaxin animal studies, there were instances of death in both the mother and fetus. Recarbrio animal studies showed harm to the fetus (abnormalities) as well as loss of the fetus. Vabomere animal studies also concluded that there was harm to the fetus. 

Regarding breastfeeding, carbapenems are present or may be present in human milk, but the effects are not known.  

Children 

Carbapenems may be used in children, except for Recarbrio and Vabomere.

• Invanz and meropenem are indicated in children 3 months of age and older. 

• Primaxin may be used in children 3 months and older and is sometimes used in neonates. However, Primaxin is not recommended for use in children with central nervous system (CNS) infections because seizures may occur. Primaxin should not be used in children who weigh less than 30 kg and have kidney problems.

• Recarbrio and Vabomere have not been studied in children younger than 18 years old and are not recommended for use in this age group. 

Are carbapenems safe?

Recalls

No carbapenem recalls found. 

Restrictions and warnings

• Patients who are hypersensitive or have had an anaphylactic reaction to a beta-lactam antibiotic (such as Augmentin, amoxicillin, or cephalexin) should not take a carbapenem.

• Serious allergic reactions may occur. Patients who have symptoms of an allergic reaction, such as hives, difficulty breathing, or facial swelling, should get medical help right away.

• Patients should be monitored for seizures and other central nervous system (CNS) effects such as tremors. These events are more likely to occur in patients with a history of CNS disorders. Tell your doctor if you have a history of CNS disorders such as seizures or brain lesions.

• Carbapenems interact with the anticonvulsants valproic acid and divalproex sodium, lowering the absorption of the anticonvulsants. This could potentially increase the risk of seizures. The combination of drugs is generally not recommended—another antimicrobial drug should be used if possible.

• Antibiotic-associated diarrhea (Clostridioides difficile-associated diarrhea) may occur. Symptoms may range from mild diarrhea to fatal colitis. Patients who experience diarrhea should contact their doctor, and if diarrhea is severe, seek emergency medical care.

• Severe skin reactions have occurred with some carbapenems. These reactions include Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), drug reaction with eosinophilia and systemic symptoms (DRESS), erythema multiforme (EM), and acute generalized exanthematous pustulosis (AGEP). If skin symptoms occur, the antibiotic should be discontinued and an alternative treatment should be discussed with the healthcare provider.

• In some cases, patients with kidney problems have experienced low platelet levels (thrombocytopenia).

Additional Invanz warning:

Intramuscularly administered Invanz should not be used in patients who are allergic to local anesthetics such as lidocaine.

Are carbapenems controlled substances?

No, carbapenems are not controlled substances.

Common carbapenems side effects

Before taking a carbapenem, talk to your doctor about what adverse effects to expect and how to address them. In general, the most common side effects associated with the use of carbapenems include:

• Stomach problems: nausea, vomiting, diarrhea or constipation, stomach pain

• Infusion site reaction

• Headache 

• Fever

• Swelling

• Insomnia 

• Shortness of breath 

• Rash/itching 

• Dizziness 

• Tingling 

• Altered mental status 

• Low blood pressure

• Vaginal inflammation

• Changes in lab values: liver function tests, hemoglobin, hematocrit, neutrophils

Less common, but severe side effects may occur. Serious side effects may include: 

• Pustules (acute generalized exanthematous pustulosis)

• Brain damage 

• Seizures 

• Hallucinations/delirium

• C. difficile-associated diarrhea

• High blood pressure

• Fast heart rate

• Superinfection (a second infection)

• Stevens-Johnson syndrome/toxic epidermal necrolysis

• Skin disorder with bullseye lesions (erythema multiforme)

• Low platelet counts

• Low granulocyte or neutrophil (types of white blood cell) counts

• Low red blood cells (anemia)

• Low white blood cell count (leukopenia)

• Liver toxicity 

• Kidney failure

If you experience symptoms of an allergic reaction, such as dizziness, hives, shortness of breath, or facial swelling, get emergency medical help.

How much do carbapenems cost?

Carbapenem medications are generally given in a hospital or clinic and therefore provided by the healthcare provider at the hospital or clinic. Because of this, carbapenems are often paid for under the medical benefit of an insurance plan. Inquire at the location where you receive your medication. You can always check SingleCare for a free savings card that saves you up to 80% on your prescription prices.