The Drug Class: Beta-Lactam and Cephalosporin Antibiotics
To understand what kind of drug is cefepime, you must first recognize its position within the larger family of antibiotics. Cefepime is part of the beta-lactam class of drugs, a widely used group characterized by a core beta-lactam ring structure. These drugs work by inhibiting bacterial cell wall synthesis, leading to cell death.
Cefepime belongs specifically to the cephalosporin family, which are categorized into generations based on their properties. Cefepime is a fourth-generation cephalosporin.
What Sets Cefepime Apart as a Fourth-Generation Cephalosporin?
As a fourth-generation cephalosporin, cefepime offers a broader spectrum of activity and key advantages over earlier generations:
- Enhanced Gram-Negative Coverage: It has a wider range of activity against Gram-negative bacteria, including resistant pathogens like Pseudomonas aeruginosa and Enterobacteriaceae.
- Greater Stability to Beta-Lactamases: Cefepime is more stable against many bacterial beta-lactamase enzymes that can inactivate older cephalosporins.
- Retained Gram-Positive Activity: It maintains potent activity against many Gram-positive bacteria, such as susceptible Staphylococcus aureus and Streptococcus pneumoniae.
- Rapid Penetration: Its structure allows quicker penetration into Gram-negative bacteria via porin channels.
How Cefepime Works: The Mechanism of Action
Cefepime kills bacteria by interfering with cell wall synthesis. It binds to penicillin-binding proteins (PBPs), enzymes essential for building the peptidoglycan cell wall. This binding inhibits the transpeptidation process, leading to defects in the cell wall and activating enzymes that break down the wall. The result is bacterial cell lysis and death.
Key Indications: When is Cefepime Used?
Cefepime is typically reserved for serious bacterial infections, particularly in hospital settings involving resistant organisms. FDA-approved uses include:
- Pneumonia: For moderate to severe cases caused by susceptible bacteria.
- Urinary Tract Infections: Covering both uncomplicated and complicated UTIs.
- Skin and Skin Structure Infections: For infections caused by susceptible organisms.
- Complicated Intra-abdominal Infections: Often used in combination with other drugs.
- Empiric Therapy for Febrile Neutropenia: Given when an infection is suspected in patients with a low white blood cell count.
Cefepime vs. Other Cephalosporins
Here is a comparison highlighting cefepime's position relative to other cephalosporins:
| Feature | Cefepime (Fourth-Generation) | Ceftriaxone (Third-Generation) | Ceftazidime (Third-Generation) |
|---|---|---|---|
| Pseudomonas Activity | Strong, covers most strains | Weak or no coverage | Strong, but more susceptible to resistance |
| Gram-Positive Activity | Retains potent Gram-positive activity, similar to ceftriaxone | Strong coverage | Weaker Gram-positive coverage than cefepime |
| Beta-Lactamase Stability | High stability, less prone to degradation by many beta-lactamases | Less stable than cefepime against certain beta-lactamases | Less stable than cefepime against certain beta-lactamases |
| Dosing Frequency | Typically every 8 or 12 hours | Often once daily, making it suitable for outpatient settings | Typically every 8 hours |
| Key Use Case | Serious hospital infections, multi-drug resistant organisms, febrile neutropenia | Wide range of community-acquired and hospital infections | Hospital infections, particularly for Pseudomonas coverage when beta-lactamase stability is less critical |
Important Considerations and Side Effects
Cefepime has potential side effects:
Common Side Effects:
- Diarrhea.
- Rash and Itching.
- Injection site reactions.
Serious Side Effects:
- Neurotoxicity: Confusion, seizures, or encephalopathy can occur, especially in patients with kidney issues receiving unadjusted doses. Dose adjustments for renal impairment are crucial.
- Clostridioides difficile-associated diarrhea (CDAD): Like other broad-spectrum antibiotics, it can cause severe diarrhea or colitis.
- Hypersensitivity Reactions: Allergic reactions, including anaphylaxis, can occur. While possible, cross-reactivity with penicillins is generally low with fourth-generation cephalosporins.
Conclusion
Cefepime is a vital fourth-generation cephalosporin antibiotic used for serious bacterial infections, particularly in hospital settings with resistant organisms. Its broad spectrum, enhanced Gram-negative activity (including P. aeruginosa), and beta-lactamase stability make it a valuable treatment. Monitoring for side effects, especially neurotoxicity in patients with kidney problems, is important. Understanding what kind of drug is cefepime clarifies its role in treating severe infections.
For more information on antibiotic use, see the FDA's detailed drug label for cefepime.
