Cephalosporins

Cephalosporins are a class of antibiotics that are used to treat a wide range of bacterial infections. They are derived from a fungus called Acremonium, and are similar in structure to penicillin. Cephalosporins work by interfering with the cell wall synthesis of bacteria, leading to the disruption of the bacterial cell wall and eventual cell death.

Generations of Cephalosporins

Cephalosporins are categorized into different generations based on their spectrum of activity and when they were developed. There are currently five generations of cephalosporins, each with varying levels of activity against different types of bacteria.

First Generation

First generation cephalosporins are effective against gram-positive bacteria, such as Staphylococcus and Streptococcus species. They are commonly used to treat skin and soft tissue infections.

Second Generation

Second generation cephalosporins have a broader spectrum of activity compared to first generation drugs. They are effective against both gram-positive and some gram-negative bacteria, making them useful for treating respiratory and urinary tract infections.

Third Generation

Third generation cephalosporins have even broader coverage against gram-negative bacteria, including some that are resistant to other antibiotics. They are often used to treat serious infections such as meningitis and septicemia.

Fourth Generation

Fourth generation cephalosporins have an extended spectrum of activity against both gram-positive and gram-negative bacteria. They also have increased resistance to beta-lactamase enzymes, which are produced by some bacteria to inactivate antibiotics.

Fifth Generation

Fifth generation cephalosporins are the most recent addition to the cephalosporin class. They have enhanced activity against multidrug-resistant gram-positive bacteria, including MRSA (Methicillin-resistant Staphylococcus aureus).

Common Side Effects

Like all antibiotics, cephalosporins can cause side effects. The most common side effects include diarrhea, nausea, vomiting, and allergic reactions such as rashes or itching. In some cases, cephalosporins can also cause more severe side effects such as liver toxicity or Clostridium difficile infection.

Study Guide

1. What is the mechanism of action of cephalosporins?
2. How are cephalosporins categorized into different generations?
3. Give examples of infections that each generation of cephalosporins is commonly used to treat.
4. What are the common side effects of cephalosporins?
5. What is the significance of the fifth generation cephalosporins?