ATC Group: S01AA Antibiotics

Amikacin is an antibiotic used for a number of bacterial infections. Amikacin works by blocking the function of the bacteria’s 30S ribosomal subunit, making it unable to produce proteins.

Ampicillin is a broad spectrum penicillin, indicated for the treatment of a wide range of bacterial infections caused by ampicillin sensitive organisms.

Azidamfenicol is an amphenicol antibiotic, which has similar profile to chloramphenicol. It is used only topically, as eye drops and ointment for treatment of susceptible bacterial infections.

Azithromycin is a macrolide antibiotic belonging to the azalide group. The molecule is constructed by adding a nitrogen atom to the lactone ring of erythromycin A. The mechanism of action of azithromycin is based upon the suppression of bacterial protein synthesis by means of binding to the ribosomal 50S sub-unit and inhibition of peptide translocation.

Benzylpenicillin is a beta-lactam antibiotic. It is bacteriocidal by inhibiting bacterial cell wall biosynthesis. Penicillin resistance can be mediated by alteration of penicillin binding proteins or development of beta-lactamases.

Chloramphenicol is a broad spectrum antibiotic which has activity against many types of Gram-positive and Gram-negative bacteria. It acts by interfering with bacterial protein synthesis. Chloramphenicol is widely distributed in body tissues and fluids and enters the cerebrospinal fluid.

Chlortetracycline is a tetracycline antibiotic isolated from Streptomyces aureofaciens. It has a role as an antiprotozoal drug, a fluorescent probe, a calcium ionophore and an antibacterial drug.

Erythromycin exerts its antimicrobial action by binding to the 50S ribosomal sub-unit of susceptible microorganisms and suppresses protein synthesis. Erythromycin is bacteriostatic and bactericidal depending on its concentration and the type of organism.

Fusidic acid belongs to a unique group of antibiotics, the fusidanes, which act to inhibit bacterial protein synthesis by blocking the lengthening of factor G. Fusidic acid is active against staphylococcus epidermidis and methicillin resistant staphylococci.

Gentamicin is usually bactericidal in action. Although the exact mechanism of action has not been fully elucidated, the drug appears to inhibit protein synthesis in susceptible bacteria by irreversibly binding to 30S ribosomal subunits.

Natamycin is a tetraene polyene antibiotic derived from Streptomyces natalensis. It possesses in vitro activity against a variety of yeast and filamentous fungi, including Candida, Aspergillus, Cephalosporium, Fusarium and Penicillium. The mechanism of action appears to be through binding of the molecule to the sterol moiety of the fungal cell membrane.

Neomycin is an aminoglycoside antibiotic and acts by binding to polysomes, inhibiting protein synthesis and generating errors in the transcription of the genetic code.

Oxytetracycline is a broad spectrum tetracycline antibiotic with activity against a large number of gram positive and gram negative bacteria. The product acts by interfering with bacterial protein synthesis.

Polymixin B is bactericidal against a wide range of gram negative bacilli. It exerts a bactericidal effect by binding to acid phospholipids in the cell wall and membranes of the bacterium, thereby rendering ineffective the osmotic barrier normally provided by the cell membrane.

Tetracyclines are taken up into sensitive bacterial cells by an active transport process. Once within the cell they bind reversibly to the 30S subunit of the ribosome, preventing the binding of aminoacyl transfer RNA and inhibiting protein synthesis and hence cell growth.

Tobramycin is an aminoglycoside antibiotic produced by Streptomyces tenebrarius. It acts primarily by disrupting protein synthesis leading to altered cell membrane permeability, progressive disruption of the cell envelope and eventual cell death. It is bactericidal at concentrations equal to or slightly greater than inhibitory concentrations.

Tyrothricin is a circular polypeptide with antibiotic and bacteriostatic activity. It is effective against gram-positive bacteria.

Vancomycin is a tricyclic glycopeptide antibiotic that inhibits the synthesis of the cell wall in sensitive bacteria by binding with high affinity to the D-alanyl-D-alanine terminus of cell wall precursor units.