ATC Group: S01A Antiinfectives

Acyclovir is an antiviral agent with activity against herpes simplex virus and varicella-zoster virus. Acyclovir inhibits the DNA polymerase of the virus, preventing further proliferation.

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.

Besifloxacin is a fluoroquinolone antibacterial indicated for the treatment of bacterial conjunctivitis.

Bibrocathol is a bismuth-containing substance which acts as antiseptic, adstringent and secretion inhibitng agent on mucous membranes and wounds. The mechanism of action is explained by its phenolic molecular structure consisting of tetrabromopyrocatechol and bismuth hydroxide that causes the precipitation of proteins and the shrinking of superficial layers of tissue. These activities result in the formation of a protective membrane against pathogenic invasion and non-specifically inhibit inflammation and secretion.

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.

Chlorhexidine is an antimicrobial agent, active against a broad spectrum of Gram-positive and Gram-negative organisms, yeasts, fungi, opportunistic anaerobes and aerobes. Chlorhexidine is mainly a “membrane-acting” agent that destroys the outer membrane of the bacteria. It is inactive on bacterial spores unless the temperatures are high.

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.

Ciprofloxacin is a fluoroquinolone antibacterial agent. The bactericidal action of ciprofloxacin results from the inhibition of both type II topoisomerase (DNA-gyrase) and topoisomerase IV, required for bacterial DNA replication, transcription, repair and recombination.

Dibrompropamidine is a member of the aromatic diamidine group of compounds, which possess bacteriostatic properties against a wide range of fungi and bacteria. These diamidines exert antibacterial action against pyrogenic cocci, antibiotic resistant staphylococci and some gram-negative bacilli. The activity of the diamidines is retained in the presence of organic matter such as pus and blood.

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.

Famciclovir is the oral prodrug of penciclovir. Famciclovir is rapidly converted in vivo into penciclovir, which has in vitro activity against herpes simplex viruses (HSV types 1 and 2), varicella zoster virus (VZV), Epstein-Barr virus and cytomegalovirus.

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.

Ganciclovir, 9-(1,3-dihydroxy-2-propoxymethyl)guanine or DHPG, is a broadspectrum virustatic agent which inhibits the replication of viruses, including viruses of the herpes group, both in vivo and in vitro: herpes simplex types 1 and 2 (HSV), cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes zoster (HZV).

Gatifloxacin is an 8-methoxyfluoroquinolone with a 3-methylpiperazinyl substituent at C7. The antibacterial action of gatifloxacin results from inhibition of DNA gyrase and topoisomerase IV. The mechanism of action of fluoroquinolones including gatifloxacin is different from that of aminoglycoside, macrolide, and tetracycline antibiotics. Therefore, gatifloxacin may be active against pathogens that are resistant to these antibiotics and these antibiotics may be active against pathogens that are resistant to gatifloxacin.

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.

Levofloxacin is a synthetic antibacterial agent of the fluoroquinolone class. As a fluoroquinolone antibacterial agent, levofloxacin acts on the DNA – DNA-gyrase complex and topoisomerase IV.

Lomefloxacin is a synthetic broad-spectrum antimicrobial agent for oral administration. Lomefloxacin should be used only to treat or prevent infections that are proven or strongly suspected to be caused by bacteria.

Moxifloxacin, a fourth-generation fluoroquinolone, has in vitro activity against a wide range of Gram-positive and Gram-negative pathogens. The bactericidal action of moxifloxacin results from the inhibition of both type II topoisomerases (DNA gyrase and topoisomerase IV) required for bacterial DNA replication, transcription and repair.

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.

Norfloxacin has a rapid bactericidal action and inhibits synthesis of bacterial deoxyribonucleic acid (DNA). Norfloxacin has a broad spectrum of antibacterial activity against gram-positive and gram-negative aerobic bacteria.

Ofloxacin is a quinolone-carboxylic acid derivative with a wide range of antibacterial activity against both Gram-negative and Gram-positive organisms. The primary mode of action of the quinolones is the specific inhibition of bacterial DNA gyrase. This enzyme is required for DNA replication, transcription, repair and recombination.

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.

Polihexanide is a broad-spectrum antiseptic with excellent tolerance and a low-risk profile. The physicochemical action on the bacterial envelope prevents or impedes the development of resistant bacterial strains. Thus, polihexanide is particularly suitable and useful in the struggle against multidrug-resistant bacteria.

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.

Povidone iodine is an iodophore that has an established use as a broad-spectrum antiseptic, mainly for the treatment of contaminated wounds and for the preoperative preparation of the skin, mucous membranes and the ocular surface. The organic complex contains approximately 10% of active available iodine. Solutions of povidone iodine gradually release iodine to exert an antimicrobial effect against bacteria, fungi, viruses, and spores. Although povidone iodine is less potent than preparations containing free iodine, it is also less toxic.

Propamidine is a member of the aromatic diamidine group of compounds which possess bacteriostatic properties against a wide range of organisms. These diamidines exert antibacterial action against pyrogenic cocci, antibiotic resistant staphylococci and some Gram-negative bacilli, the activity of the diamidines being retained in the presence of organic matter such as tissue fluids, pus and serum.

The sulfonamides are bacteriostatic agents and the spectrum of activity is similar for all. Sulfonamides inhibit bacterial synthesis of dihydrofolic acid by preventing the condensation of the pteridine with aminobenzoic acid through competitive inhibition of the enzyme dihydropteroate synthetase.

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.

Zinc blocks the intestinal absorption of copper from the diet and the reabsorption of endogenously secreted copper. Zinc induces the production of metallothionein in the enterocyte, a protein that binds copper thereby preventing its transfer into the blood. The bound copper is then eliminated in the stool following desquamation of the intestinal cells.