Difference Between Penicillin and Cephalosporin

The key difference between penicillin and cephalosporin is that penicillin is more susceptible to β-lactamases, whereas cephalosporin is less susceptible to β-lactamases.

Both penicillin and cephalosporin are antibacterial drugs. Furthermore, these compounds act by inhibiting transpeptidases (the enzyme that catalyzes the synthesis of peptidoglycan).

1. Overview and Key Difference
2. What is Penicillin
3. What is Cephalosporin
4. Side by Side Comparison – Penicillin vs Cephalosporin in Tabular Form
4. Summary

What is Penicillin?

Penicillin is an antibiotic drug we use against many bacterial infections. The name penicillin is used for a group of drugs including penicillin G, penicillin V, procaine penicillin and benzathine penicillin. Furthermore, the discovery of penicillin was by Alexander Fleming in 1928.

Key Difference - Penicillin vs Cephalosporin

Figure 1: Alexander Fleming

Moreover, this drug is effective against infections caused by staphylococci and streptococci. These drugs were among the first medications for bacterial infections, and even today, they are widely used. However, many bacteria types have developed resistance against these drugs now.

The metabolism of penicillin occurs in the liver, and the elimination half-life is between 0.5 to 56 hours. The excretion of the drug can occur in kidneys. Moreover, the routes of administration of these drugs include oral administration, intravenous administration and intramuscular administration. Some common side effects regarding this drug include the following:

Diarrhoea
Hypersensitivity
Nausea
Rash
Neurotoxicity
Utricaria
Superinfection, etc.

What is Cephalosporin?

A cephalosporin is a group of β-lactam antibiotics derived from the fungus Acremonium. There is a subgroup of this drug class named “cephems”. Moreover, the discovery of cephalosporin was in 1945 by the Italian pharmacologist Giuseppe Brotzu. We use this drug to treat bacterial infections. Also, the first generation of cephalosporin is mainly active against gram-positive bacteria. Furthermore, patients can use this drug if they are allergic to penicillin. It is because the biological target for this drug is penicillin-binding proteins.

Difference Between Penicillin and Cephalosporin

Figure 01: A List of Drugs in the Cephalosporin Drug Class

However, there are some adverse effects of this drug as well:

Diarrhoea
Nausea
Rash
Electrolytic disturbances
Pain and inflammation at the injection site, etc.

What is the Difference Between Penicillin and Cephalosporin?

Both penicillin and cephalosporin are groups of antibacterial drugs. The key difference between penicillin and cephalosporin is that penicillin is more susceptible to β-lactamases, whereas cephalosporin is less susceptible to β-lactamases. When considering the first discovery, penicillin was found by Alexander Fleming, and cephalosporin was found by the Italian pharmacologist Giuseppe Brotzu.

Summary – Penicillin vs Cephalosporin

Both penicillin and cephalosporin are groups of antibacterial drugs. But, the key difference between penicillin and cephalosporin is that penicillin is more susceptible to β-lactamases, whereas cephalosporin is less susceptible to β-lactamases.

Reference:

1. Society for Microbiology and Infection. “Penicillin’s & Cephalosporins Basics.” LinkedIn SlideShare, 14 Oct. 2013, Available here.

Image Courtesy:

1. “Alexander-fleming” By National Library of Medicine. Transferred from nl.wikipedia to Commons by Hardscarf using CommonsHelper (Public Domain) via Commons Wikimedia
2. “Cephalosporins Generation1” (Public Domain) via Commons Wikimedia