Cefadroxil is a new semisynthetic cephalosporin with a broad antibacterial spectrum and a high chemotherapeutic potential when administered orally. Many studies have established the efficacy of the administration of once- or twice-daily cefadroxil in the management of infections in the respiratory tract, urinary tract, skin and soft tissues, and bones and joints.

Amoxicillin is one of the widely prescribed antibacterial agents, which was discovered by scientists at Beecham Research Laboratories in 1972. In the US GlaxoSmithKline markets it under the original brand name Amoxil. It is the first line treatment for middle ear infections. It is also used for strep throat, pneumonia, skin infections, and urinary tract infections it is taken by mouth. Amoxicillin inhibits the third and final stage of bacterial cell wall synthesis by preferentially binding to specific penicillin-binding proteins (PBPs) that are located inside the bacterial cell wall. This results in a formation of defective cell wall and a cell death. Common side effects include nausea and rash. It may also increase the risk of yeast infections and, when used in combination with clavulanic acid, diarrhea. It should not be used in those who are allergic to penicillin.

Cephalexin is a semisynthetic cephalosporin antibiotic intended for oral administration. In vitro tests demonstrate that the cephalosporins are bactericidal because of their inhibition of cell-wall synthesis. Cephalexin has been shown to be active against most strains of the following microorganisms both in vitro: Staphylococcus aureus (including penicillinase-producing strains), Streptococcus pneumoniae (penicillin-susceptible strains), Streptococcus pyogenes, Escherichia coli, Haemophilus influenzae, Klebsiella pneumoniae, Moraxella (Branhamella) catarrhalis, Proteus mirabilis. Cephalexin is indicated for the treatment of the respiratory tract, skin and skin structure, bone and genitourinary tract infections when caused by susceptible strains of the designated microorganisms.

Minocycline is a tetracycline analog, having a 7-dimethylamino and lacking the 5 methyl and hydroxyl groups, which is effective against tetracycline-resistant staphylococcus infections. Minocycline has many brand names one of them is minocin, Minocin is indicated in the treatment of the following infections due to susceptible isolates of the designated bacteria: Rocky Mountain spotted fever, typhus fever and the typhus group, Q fever, rickettsialpox and tick fevers caused by rickettsiae. Respiratory tract infections caused by Mycoplasma pneumoniae. Lymphogranuloma venereum caused by Chlamydia trachomatis. Psittacosis (Ornithosis) due to Chlamydophila psittaci etc. Minocycline is indicated for the treatment of infections caused by the following Gram-negative bacteria when bacteriologic testing indicates appropriate susceptibility to the drug: Escherichia coli. Enterobacter aerogenes. Shigella species etc. MINOCIN also is indicated for the treatment of infections caused by the following Gram-positive bacteria when bacteriologic testing indicates appropriate susceptibility to the drug: Upper respiratory tract infections caused by Streptococcus pneumoniae. Skin and skin structure infections caused by Staphylococcus aureus (Note: Minocycline is not the drug of choice in the treatment of any type of staphylococcal infection, etc. When penicillin is contraindicated, minocycline is an alternative drug in the treatment of the following infections: Meningitis due to Neisseria meningitidis. Syphilis caused by Treponema pallidum subspecies pallidum. Yaws caused by Treponema pallidum subspecies pertenue, etc. Minocycline passes directly through the lipid bilayer or passively diffuses through porin channels in the bacterial membrane. Minocycline inhibits protein synthesis by binding to 30S and possibly 50S ribosomal subunits of susceptible bacteria.

Doxycycline hyclate (Vibramycin, Periostat, Vibra-Tabs) is salt of tetracycline antibiotic Doxycycline, that used to treat many kinds of infections, like dental, skin, respiratory, and urinary tract infections. It also treats acne, Lyme disease, malaria, and certain sexually transmitted diseases. Doxycycline hyclate is a light-yellow crystalline powder which is soluble in water, while doxycycline monohydrate is very slightly soluble in water. Doxycycline is bacteriostatic, inhibiting bacterial protein synthesis due to disruption of transfer RNA and messenger RNA at ribosomal sites. Doxycycline hyclate is indicated for use in the treatment of chronic adult periodontitis for a gain in clinical attachment, reduction in probing depth, and reduction in bleeding on probing.

Ampicillin is a penicillin beta-lactam antibiotic. The following gram-negative and gram-positive bacteria have been shown in in vitro studies to be susceptible to ampicillin: Hemolytic and nonhemolytic streptococci, Streptococcus pneumoniae, Nonpenicillinase-producing staphylococci, Clostridium spp., B. anthracis, Listeria monocytogenes, most strains of enterococci, H. influenzae, N. gonorrhoeae, N. meningitidis, Proteus mirabilis, many strains of Salmonella, Shigella, and E. coli. Ampicillin is indicated in the treatment of bacterial meningitis, septicemia, endocarditis, urinary tract, gastrointestinal, respiratory tract infections caused by susceptible strains of the designated organisms.

Discovered as natural products from actinomycetes soil bacteria, the tetracyclines were first reported in the scientific literature in 1948. They were noted for their broad spectrum antibacterial activity and were commercialized with clinical success beginning in the late 1940s to the early 1950s. By catalytic hydrogenation of Aureomycin, using palladium metal and hydrogen, the C7 deschloro derivative was synthesized, producing a compound of higher potency, a better solubility profile, and favorable pharmacological activity; it was subsequently named tetracycline. Tetracyclines are primarily bacteriostatic and exert their antimicrobial effect by the inhibition of protein synthesis by binding to the 30S ribosomal subunit. Tetracycline is active against a broad range of gram-negative and gram-positive organisms. Tetracycline is indicated in the treatment of infections caused by susceptible strains. To reduce the development of drug-resistant bacteria and maintain the effectiveness of tetracycline hydrochloride and other antibacterial drugs, tetracycline hydrochloride should be used only to treat or prevent infections that are proven or strongly suspected to be caused by bacteria.

Oxytetracycline, a tetracycline analog isolated from the actinomycete streptomyces rimosus, was the second of the broad-spectrum tetracycline group of antibiotics to be discovered The drug is used for the prophylaxis and local treatment of superficial ocular infections due to oxytetracycline- and polymyxin-sensitive organisms for animal use only. These infections include the following: Ocular infections due to streptococci, rickettsiae E. coli, and A. aerogenes (such as conjunctivitis, keratitis, pinkeye, corneal ulcer, and blepharitis in dogs); ocular infections due to secondary bacterial complications associated with distemper in dogs; and ocular infections due to bacterial inflammatory conditions which may occur secondary to other diseases in dogs. Allergic reactions may occasionally occur. Treatment should be discontinued if reactions are severe. If new infections due to nonsensitive bacteria or fungi appear during therapy, appropriate measures should be taken. Oxytetracycline inhibits cell growth by inhibiting translation. It binds to the 30S ribosomal subunit and prevents the amino-acyl tRNA from binding to the A site of the ribosome. The binding is reversible in nature. Oxytetracycline is lipophilic and can easily pass through the cell membrane or passively diffuses through porin channels in the bacterial membrane.

Alatrofloxacin is a fluoroquinolone antibiotic developed as a mesylate salt and was sold under brand name Trovan, but was withdrawn from the U.S. market in 2001. Trovan was indicated for the treatment of patients initiating therapy in in-patient health care facilities (i.e., hospitals and long term nursing care facilities) with serious, life- or limb-threatening infections caused by susceptible strains of the designated microorganisms in the conditions listed below. Nosocomial pneumonia caused by Escherichia coli, Pseudomonas aeruginosa, Haemophilus influenzae, or Staphylococcus aureus. Community acquired pneumonia caused by Streptococcus pneumoniae, Haemophilus influenzae, Klebsiella pneumoniae, Staphylococcus aureus. Complicated intra-abdominal infections, including post-surgical infections caused by Escherichia coli. Gynecologic and pelvic infections including endomyometritis, parametritis, septic abortion and post-partum infections caused by Escherichia coli, Bacteroides fragilis, viridans group streptococci, Enterococcus faecalis. Complicated skin and skin structure infections, including diabetic foot infections, caused by Staphylococcus aureus, Streptococcus agalactiae, Pseudomonas aeruginosa, Enterococcus faecalis, Escherichia coli, or Proteus mirabilis. After intravenous administration, alatrofloxacin is rapidly converted to trovafloxacin, which is responsible for therapeutic effect. Plasma concentrations of alatrofloxacin are below quantifiable levels within 5 to 10 minutes of completion of a 1 hour infusion.

Temafloxacin (marketed by Abbott Laboratories as Omniflox) is almost completely absorbed from the gastrointestinal tract, with an absolute bioavailability of approximately 93% and is not greatly affected by food. The time to reach peak concentrations ranges between 2 and 3 hours. In addition to the broad spectrum of activity all fluoroquinolones have against gram-negative pathogens, temafloxacin has improved antimicrobial activity against gram-positive aerobic cocci, intracellular microorganisms, and anaerobes. The bactericidal action of temafloxacin results from interference with the activity of the bacterial enzymes DNA gyrase. Omniflox was approved to treat lower respiratory tract infections, genital and urinary infections like prostatitis, and skin infections in the U.S. by the Food and Drug Administration in January 1992. Severe adverse reactions, including allergic reactions and hemolytic anemia, developed in about fifty patients during the first four months of its use, leading to three patient deaths. Abbott withdrew the drug from sale in June 1992.