Cephalosporin generations have confused tens of thousands of students; their names and individual characteristics proving to be nothing other than a nexus of confusion. Here, we go some way toward clarifying what is otherwise an arcane subject.
Whilst we are examining fourth generation cephalosporins here, you can find the other generations in the links below:
- First-Generation Cephalosporins
- Second-Generation Cephalosporins
- Third-Generation Cephalosporins
- Fourth-Generation Cephalosporins
- Fifth-Generation Cephalosporins
Each review goes through the main examples of each class, their pharmacology, what differentiates them from earlier and later classes, as well as assessing some of the main side effects and drug interactions associated with each generation.
What are 4th Generation Cephalosporins?
Fourth generation cephalosporins are, like their predecessors and successor, members of the beta-lactam class of antibacterial drugs.
Like penicillins, cephalosporins are bactericidal in effect – meaning that they actively kill bacteria rather than merely suppressing their growth (an effect that defines bacteriostatic antibacterials).
Fourth generation cephalosporins include drugs such as:
Fourth generation cephalosporins are easy to remember. One of the easiest pharmacology mnemonics is ‘Quinoa Pie – Cefquinome, Cefepime, Cefpirome’ – these three main drugs begin, after the prefix ‘cef’, with either P or Q – two continuous letters in the alphabet.
Also – think about the suffix. We’ve just pointed out two of the three drugs contain P or ‘pi’, but it’s also worth noting that all three fourth generation drugs end in ‘me’. This generation is, in other words, one of the easiest and most memorable of all.
Spectrum of Activity
Fourth generation cephalosporins have broad-spectrum activity. Let’s review some of their main pharmacological features:
- Cefquinome is only used for veterinary purposes. It is resistant to beta-lactamase. Cefquinome is used to treat infections such as bovine respiratory disease, mastitis, dermatitis, and respiratory tract infections in pigs.
- Unlike the second and third cephalosporin generations, the fourth generation has improved activity against Gram-positive organisms (similar in extend to first-generation drugs). They are extended-spectrum drugs.
- Fourth generation drugs are also zwitterionic. They have greater beta-lactamase resistance than third-generation drugs.
- Cefpirome and cefepime are both active against Pseudomonas aeruginosa.
Adverse effects are like other cephalosporins of other generations. Side effects include nausea, vomiting, diarrhea, injection site pain and abdominal pain. Some patients experience skin rash and headache.
Check out the links at the top of this page for more information on the pharmacology of the remaining cephalosporin generations.