Classification of Antimicrobial Drugs

Study Notes

Antimicrobial Drugs Overview

Antimicrobial drugs are chemicals designed to target and harm pathogenic organisms while being safe for the host.

Microbial Entities

Microbes include bacteria, viruses, and fungi, whereas parasites refer to protozoa and helminths.

Classification Basis

Classification of antimicrobial drugs is based on:
- Type of organisms they act against
- Chemical structure
- Mechanism of action
- Spectrum of activity
- Mode of action

Chemical Structure Categories

Types include:
- Beta-lactam antibiotics
- Sulfonamides
- Tetracyclines
- Polyene antimicrobial drugs
- Azoles

Spectrum of Activity

Antimicrobial agents can be classified as:
- Narrow spectrum: effective against specific bacteria (e.g., Erythromycin, Gentamicin, Streptomycin, Penicillin G)
- Broad spectrum: effective against a wide range of bacteria (e.g., Chloramphenicol, Tetracyclines)

Action Types

Mode of action can be:
- Bacteriostatic: inhibits growth or reproduction (e.g., Sulfonamides, Tetracyclines, Erythromycin)
- Bactericidal: kills bacteria (e.g., Penicillins, Cephalosporins, Ciprofloxacin)

Mechanisms of Action

Inhibitors categorized by their action:
- Cell wall synthesis inhibitors (e.g., Beta-lactams, Vancomycin)
- Protein synthesis inhibitors (e.g., Tetracycline, Chloramphenicol)
- Folic acid synthesis inhibitors (e.g., Sulfonamides)
- Drugs that disrupt cell membranes (e.g., Polymyxins)

Beta-lactam Antibiotics

Subcategories:
- Natural penicillins (e.g., Penicillin G)
- Synthetic penicillins (e.g., Acid-resistant, Penicillinase-resistant, Extended-spectrum)

Penicillin G

Variants include:
- Sodium penicillin G
- Procaine penicillin G
- Benzathine penicillin G
Has limitations like narrow spectrum, acid lability, and susceptibility to beta-lactamase.

Synthetic Penicillins

Types include:
- Acid-resistant penicillin (e.g., Penicillin V)
- Penicillinase-resistant (e.g., Methicillin, Oxacillin)
- Extended spectrum (e.g., Ampicillin, Ticarcillin)

Beta-lactamase Inhibitors

Potent inhibitors of beta-lactamase, combined with penicillins to enhance effectiveness (e.g., Clavulanic acid, Tazobactam).

Combination Drugs

Augmentin: Amoxicillin + Clavulanic acid
Unasyn: Ampicillin + Sulbactam
Zosyn: Piperacillin + Tazobactam
Timentin: Ticarcillin + Clavulanic acid

Cephalosporins Classification

Classified into four generations based on their effectiveness and resistance levels.
First generation includes:
- Cefadroxil
- Cefazolin
- Cephalexin
- Cephalothin
Primarily active against gram-positive cocci, ineffective against methicillin-resistant strains.

Description

Explore the classification of antimicrobial drugs through this engaging flashcard quiz. Learn about the different types of microbes and parasites, as well as the basis for the classification of these crucial drugs. Ideal for students in microbiology or pharmacology.