Azidamfenicol is a semi-synthetic chloramphenicol in which the nitro moiety is replaced with a methylsulphone and the dichloroacetamide is replaced with azidoacetamide. Azidamfenicol is a broad spectrum antibiotic with good activity against Gram-negative and anaerobic bacteria.

Propamidine, an aromatic diamidine compound, is widely used as an antimicrobial agent. Propamidine isethionate, the salt of propamidine with isethionic acid, is used in the treatment of Acanthamoeba infection. Diseases caused by Acanthamoeba include keratitis and granulomatous amoebic encephalitis.

Neomycin is an aminoglycoside antibiotic found in many topical medications such as creams, ointments, and eye drops. In vitro tests have demonstrated that neomycin is bactericidal and acts by inhibiting the synthesis of protein in susceptible bacterial cells. It is effective primarily against gram-negative bacilli but does have some activity against gram-positive organisms. Neomycin is active in vitro against Escherichia coli and the Klebsiella-Entero. Topical uses include treatment for superficial eye infections caused by susceptible bacteria (used in combination with other anti-infective), treatment of otitis externa caused by susceptible bacteria, treatment or prevention of bacterial infections in skin lesions, and use as a continuous short-term irrigant or rinse to prevent bacteriuria and gram negative rod bacteremia in bacteriuria patients with indwelling catheters. May be used orally to treat hepatic encephalopathy, as a perioperative prophylactic agent, and as an adjunct to fluid and electrolyte replacement in the treatment of diarrhea caused to enter pathogenic E. coli (EPEC). Neomycin sulfate has been shown to be effective adjunctive therapy in hepatic coma by reduction of the ammonia forming bacteria in the intestinal tract. The subsequent reduction in blood ammonia has resulted in neurologic improvement. To reduce the development of drug-resistant bacteria and maintain the effectiveness of Neomycin Sulfate Oral Solution and other antibacterial drugs, susceptible bacteria should use Neomycin Sulfate Oral Solution only to treat or prevent infections that are proven or strongly suspected to be caused. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy. Neomycin binds to four nucleotides of 16S rRNA and a single amino acid of protein S12. This interferes with decoding site near nucleotide 1400 in 16S rRNA of 30S subunit. This region interacts with the wobble base in the anticodon of tRNA. This leads to interference with the initiation complex, misreading of mRNA so incorrect amino acids are inserted into the polypeptide leading to nonfunctional or toxic peptides and the breakup of polysomes into nonfunctional monosomes

Polymyxin B is a lipopeptide antibiotic isolated from Bacillus polymyxa. Its basic structure consists of a polycationic peptide ring and a tripeptide side chain with a fatty acid tail. Polymyxin B is a mixture of at least four closely related components, polymyxin B1 to B4, with polymyxin B1 and B2 being the two major components. Polymyxin B acts on Gram-negative bacteria by interacting with lipopolysaccharide (LPS) of the outer membrane and destabilizing it. Polymyxin B is indicated for the treatment of many bacterial diseases such as meningeal infections, urinary tract infections and bacteremia.

Tyrothricin is a mixture of non-ribosomal peptides produced by Brevibacillus brevis, now known as Aneurinibacillus migulanus, a gram positive aerobic bacteria. The compound mixture shows activity against bacteria, fungi and some viruses. A very interesting feature of AMPs is the fact, that even in vitro it is almost impossible to induce resistances. It is a locally effective antibiotic effective against gram-positive bacteria. It is sometimes combined with benzocaine 5 mg (Tyrozets) to provide relief from sore throats. Recommended for short-term relief of symptoms of oral and throat inflammation. Prevention of infections before/during mouth and throat operations (tooth extractions, gum surgical treatment). Tyrothricin inhibits protein biosynthesis of gram-positive organisms, but is completely ineffective against gram-negative.

Kanamycin (a mixture of kanamycin A, B and C) is an aminoglycoside bacteriocidal antibiotic, available in oral, intravenous, and intramuscular forms, and used to treat a wide variety of infections. It is effective against Gram-negative bacteria and certain Gram-positive bacteria. Aminoglycosides work by binding to the bacterial 30S ribosomal subunit, causing misreading of t-RNA, leaving the bacterium unable to synthesize proteins vital to its growth. Serious side effects include tinnitus or loss of hearing, toxicity to kidneys, and allergic reactions to the drug. Mixing of an aminoglycoside with beta-lactam-type antibiotics (penicillins or cephalosporins) may result in a significant mutual inactivation. Even when an aminoglycoside and a penicillin-type drug are administered separately by different routes, a reduction in aminoglycoside serum half-life or serum levels has been reported in patients with impaired renal function and in some patients with normal renal function.

Gatifloxacin is a recently developed antibacterial agent differing from earlier fluoroquinolones by the presence of a methoxy group at the C-8 position. The presence of the methoxy group has conferred improved antibacterial activity against both Gram-positive and Gram-negative organisms, making gatifloxacin a broad-spectrum antimicrobial agent applicable in many clinical settings. Gatifloxacin is sold under the brand Zymar and is indicated for the treatment of bacterial conjunctivitis caused by susceptible strains of the following organisms: Aerobic Gram-Positive Bacteria: Cornyebacterium propinquum, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus mitis, Streptococcus pneumoniae and Aerobic Gram-Negative Bacteria: Haemophilus influenza. The antibacterial action depends on blocking of bacterial DNA replication by binding itself to an enzyme called DNA gyrase, which allows the untwisting required to replicate one DNA double helix into two. Notably the drug has 100 times higher affinity for bacterial DNA gyrase than for mammalian. In addition, Gatifloxacin inhibits bacterial topoisomerase IV. This enzyme is an enzyme known to play a key role in the partitioning of the chromosomal DNA during bacterial cell division. 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. There is no cross-resistance between gatifloxacin and the aforementioned classes of antibiotics. Cross-resistance has been observed between systemic gatifloxacin and some other fluoroquinolones.

Levofloxacin is the L-isomer of the racemate, ofloxacin, a quinolone antimicrobial agent. Levofloxacin is used for oral and intravenous administration. Levofloxacin is sold under brand name levaquin and is used to treat infections in adults (≥18 years of age) caused by designated, susceptible bacteria such as, pneumonia: nosocomial and community acquired; skin and skin structure infections: complicated and uncomplicated; chronic bacterial prostatitis; inhalational anthrax. In addition this drug is used to treat plague; urinary tract infections: complicated and uncomplicated; acute pyelonephritis; acute bacterial exacerbation of chronic bronchitis and acute bacterial sinusitis. Levofloxacin, like other fluoroquinolones, inhibits the bacterial DNA gyrase, halting DNA replication. This results in strand breakage on a bacterial chromosome, supercoiling, and resealing. In addition, levofloxacin inhibits a bacterial type II topoisomerase.

Penciclovir (DENAVIR®) is a synthetic acyclic guanine derivative with antiviral activity, mainly used to treat infections from herpes simplex virus (HSV) types 1 and 2. In cells infected with HSV-1 or HSV-2, the viral thymidine kinase phosphorylates penciclovir to a monophosphate form that, in turn, is converted by cellular kinases to the active form penciclovir triphosphate. Biochemical studies demonstrate that penciclovir triphosphate inhibits HSV polymerase competitively with deoxyguanosine triphosphate. Consequently, herpes viral DNA synthesis and, therefore, replication are selectively inhibited. Famciclovir (FAMVIR®) is a prodrug form of penciclovir with improved oral bioavailability.