Methacycline is a tetracycline antibiotic. Similar to other tetracyclines, it has a wide spectrum of antimicrobial action. It is active against most Gram-positive bacteria (pneumococci, streptococci, staphylococci) and Gram-negative bacteria (E. coli, salmonella, shigella, etc.), and towards agents causing onithosis, psittacosis, trachoma, and some Protozoa. Like other tetracyclines, the general usefulness of methacycline has been reduced with the onset of bacterial resistance. Methacycline inhibits the binding of aminoacyl-tRNA to the mRNA-ribosome complex. Methacycline inhibits cell growth by inhibiting translation. It binds to the 16S part of the 30S ribosomal subunit and prevents the amino-acyl tRNA from binding to the A site of the ribosome. Methacycline is mostly used for the treatment of acute bacterial exacerbations of chronic bronchitis.

Cloxacillin is a derivative of penicillin for the treatment of broad spectrum of bacterial infections. The drug exerts its action by inhiiting bacterial beta-lactamase (penicillin-binding proteins).

Nalidixic acid is a quinolone antibacterial indicated for the treatment of urinary tract infections. Nalidixic acid has marked antibacterial activity against gram-negative bacteria including Enterobacter species, Escherichia coli, Morganella Morganii; Proteus Mirabilis, Proteus vulgaris, and Providencia rettgeri. Pseudomonas species are generally resistant to the drug. It is suggested that nalidixic acid acts by inhibiting bacterial DNA gyrase.

Cephalothin is a first generation, semisynthetic analogue of natural cephalosporin antibiotic. The in-vitro bactericidal action of Cephalothin results from inhibition of cell-wall synthesis. In general, Cephalothin has higher activity against Gram positive than Gram negative organisms. Cephalothin is primarily indicated in conditions like bone and joint infection, genitourinary tract infections, respiratory tract infections, soft tissue and skin infections and others. The severe or irreversible adverse effects of Cephalothin, which give rise to further complications, include nephrotoxicity, hemolytic anemia. Cephalothin produces potentially life-threatening effects, which include anaphylaxis, serum sickness syndrome. The symptomatic adverse reactions produced by Cephalothin are: rashes, urticaria, allergic reactions, thrombophlebitis, pain at injection site. Co-administration of diuretics, such as furanthril, ethacrynic acid and nephrotoxic antibiotics may increase the risk of renal damage. Reciprocal inactivation could be observed during in vitro mixing of Cephalothin with aminoglycosides.

Sulfaphenazole is an oral antibiotic, which was used for the treatment of bacterial infections under the name Sulfabid. The drug was found to block folate synthesis in bacterias by inhibiting the enzyme dihydropteroate synthase. Sulfaphenazole is also known to inhibit CYP2C9 with high potency and specificity. Sulfabid is no longer marketed in the USA.

Sulfachlorpyridazine is a broad spectrum antibacterial compound which is effective in the treatment of infections caused by gram-positive and gram-negative organisms that are commonly susceptible to sulfonamide therapy and which has been proven by laboratory and field experiments to be highly effective against diseases caused by Escherichia coli. Sulfachlorpyridazine has a rapid onset of action in several species of animals following both oral and parenteral administration. Sulfachlorpyridazine (brand name Vetisulid) is especially indicated for the treatment of diarrhea caused or complicated by E. coli (colibacillosis) in calves under 1 month of age: Vetisulid powder is also indicated for the treatment of colibacillosis in swine. Sulfachlorpyridazine is a dihydropteroate synthase inhibitor.

Methicillin sodium anhydrous is a sodium salt of methicillin (methicillin). Methicillin is an antibiotic formerly used in the treatment of bacterial infections caused by organisms of the genus Staphylococcus. Methicillin is a semisynthetic derivative of penicillin. It was first produced in the late 1950s and was developed as a type of antibiotic called penicillinase-resistant penicillin—it contained a modification to the original penicillin structure that made it resistant to a bacterial enzyme called penicillinase (beta-lactamase). Compared to other penicillins that face antimicrobial resistance due to β-lactamase, it is less active, can be administered only parenterally, and has a higher frequency of interstitial nephritis, an otherwise-rare adverse effect of penicillins. However, the selection of meticillin depended on the outcome of susceptibility testing of the sampled infection, and since it is no longer produced, it is also not routinely tested for anymore.

Pheneticillin (phenoxyethylpenicillin) is an oral penicillin used for the treatment of upper respiratory tract infections; lower respiratory tract infections; skin and soft tissue infections. Pheneticillin inhibits the synthesis of the cell wall by inhibiting the penicillin binding proteins (PBPs) function. It is well absorbed from the gastrointestinal tract. It reaches the pleural and peritoneal cavities but doesn’t cross the blood-brain barrier. Diarrhea has sometimes occurred with therapeutic doses in man.

Rolitetracycline, launched in the late 1950s, was the first of the semi -synthetic tetracyclines. Rolitetracycline is formed by a Mannich condensation of formaldehyde and pyrrolidine with tetracycline. Rolitetracycline is a pro -drug of tetracycline, in which the pyrrolidine moiety improves bioavailability compared with tetracycline. Rolitetracycline has broad spectrum Gram positive activity in vivo, but pH instability limits use to parenteral administration. Rolitetracycline passively diffuses through porin channels in the bacterial membrane and reversibly binds to the 30S ribosomal subunit, preventing binding of tRNA to the mRNA-ribosome complex, and thus interfering with protein synthesis.

Furaltadone is a veterinary product, which is marketed for the treatment and control of salmonella infection of poultry. In 1960th was investigated the antibacterial properties of this drug against human Rhodesian sleeping sickness. In three cases treated, two were apparently curated and the third relapsed. No toxic effects attributable to the product had been observed. However, the further investigation of the furaltadone in human was not provided.