Stavudine is a nucleoside reverse transcriptase inhibitor (NRTI) with activity against Human Immunodeficiency Virus Type 1 (HIV-1). Stavudine is phosphorylated to active metabolites that compete for incorporation into viral DNA. They inhibit the HIV reverse transcriptase enzyme competitively and act as a chain terminator of DNA synthesis. The lack of a 3'-OH group in the incorporated nucleoside analogue prevents the formation of the 5' to 3' phosphodiester linkage essential for DNA chain elongation, and therefore, the viral DNA growth is terminated. Stavudine inhibits the activity of HIV-1 reverse transcriptase (RT) both by competing with the natural substrate dGTP and by its incorporation into viral DNA. Stavudine is used for the treatment of human immunovirus (HIV) infections. Stavudine is sold under the brand name Zerit among others.

The nucleoside analog 2',3'-dideoxycytidine (ddCyd), also known as Zalcitabine is a nucleoside analog reverse transcriptase inhibitor (NRTI) sold under the trade name Hivid. HIVID is indicated in combination with antiretroviral agents for the treatment of HIV infection. It is used as part of a combination regimen with antiretroviral agents. But it was discontinued by Roche Pharmaceuticals on December 31, 2006 due to the availability of newer HIV medicines. Within cells, zalcitabine is converted to the active metabolite, dideoxycytidine 5'-triphosphate (ddCTP), by the sequential action of cellular enzymes. Dideoxycytidine 5'-triphosphate inhibits the activity of the HIV-reverse transcriptase both by competing for utilization of the natural substrate, deoxycytidine 5'-triphosphate (dCTP), and by its incorporation into viral DNA. The lack of a 3'- OH group in the incorporated nucleoside analogue prevents the formation of the 5' to 3' phosphodiester linkage essential for DNA chain elongation and, therefore, the viral DNA growth is terminated. The active metabolite, ddCTP, is also an inhibitor of cellular DNA polymerasebeta and mitochondrial DNA polymerase-gamma and has been reported to be incorporated into the DNA of cells in culture.

Lomefloxacin hydrochloride (marketed under the following brand names in English speaking countries Maxaquin, Okacyn, Uniquin) is a fluoroquinolone antibiotic used to treat bacterial infections. It is used to treat chronic bronchitis, as well as complicated and uncomplicated urinary tract infections. It is also used as a prophylactic or preventative treatment to prevent urinary tract infections in patients undergoing transrectal or transurethral surgical procedures. Flouroquinolones such as lomefloxacin possess excellent activity against gram-negative aerobic bacteria such as E.coli and Neisseria gonorrhoea as well as gram-positive bacteria including S. pneumoniae and Staphylococcus aureus. They also posses effective activity against shigella, salmonella, campylobacter, gonococcal organisms, and multi drug resistant pseudomonas and enterobacter. Lomefloxacin is a bactericidal fluoroquinolone agent with activity against a wide range of gram-negative and gram-positive organisms. The bactericidal action of lomefloxacin results from interference with the activity of the bacterial enzymes DNA gyrase and topoisomerase IV, which are needed for the transcription and replication of bacterial DNA. DNA gyrase appears to be the primary quinolone target for gram-negative bacteria. Topoisomerase IV appears to be the preferential target in gram-positive organisms. Interference with these two topoisomerases results in strand breakage of the bacterial chromosome, supercoiling, and resealing. As a result DNA replication and transcription is inhibited.

Enoxacin is an oral broad-spectrum fluoroquinolone antibacterial agent used in the treatment of urinary tract infections and gonorrhea. Enoxacin is bactericidal drugs, eradicating bacteria by interfering with DNA replication. Like other fluoroquinolones, enoxacin functions by inhibiting bacterial DNA gyrase and topoisomerase IV. The inhibition of these enzymes prevents bacterial DNA replication, transcription, repair and recombination. Enoxacin is active against many Gram-positive bacteria. After oral administration enoxacin is rapidly and well absorbed from the gastrointestinal tract. The antibiotic is widely distributed throughout the body and in the different biological tissues. Tissue concentrations often exceed serum concentrations. The binding of enoxacin to serum proteins is 35 to 40%. The serum elimination half-life, in subjects with normal renal function, is approximately 6 hours. Approximately 60% of an orally administered dose is excreted in the urine as unchanged drug within 24 hours. Enoxacin, like other fluoroquinolones, is known to trigger seizures or lower the seizure threshold. The compound should not be administered to patients with epilepsy or a personal history of previous convulsive attacks as may promote the onset of these disorders.

Didanosine was developed by Bristol-Myers Squibb in collaboration with the NIH for the treatment of HIV-1 infections. Upon administration the drug is metabolized to the active metabolite which inhibits HIV-1 reverse transcriptase both by competing with deoxyadenosine 5'-triphosphate and by its incorporation into viral DNA. Didanosine was approved by FDA under the name Videx (among the other names).

Loracarbef (KT3777) is carbacephem antibiotic structurally identical to cefaclor, except that the sulfur atom of position 1 of the cephem nucleus has been replaced by carbon. It showed good affinity for penicillin-binding proteins. At low concentrations (< 2 mg/L) in vitro, it inhibits Streptococcus pneumoniae, S. pyogenes, beta-haemolytic streptococci groups B, C and G. Proteus mirabilis and Moraxella catarrhalis, including beta-lactamase-producing strains. At therapeutic plasma concentrations it is also active in vitro against most strains of Staphylococcus aureus, S. saprophyticus, Escherichia coli and beta-lactamase-positive and -negative strains of Haemophilus influenzae. Loracarbef has been indicated in the treatment of patients with mild to moderate infections caused by susceptible strains of the designated microorganisms.

Cefmetazole is a semisynthetic cephamycin antibiotic. It has a broad spectrum of activity comparable to that of the second-generation cephalosporins, covering gram-positive, gram-negative, and anaerobic bacteria. Its bactericidal action results from inhibition of cell wall synthesis. It effectively treats abdominal and respiratory tract infections, pelvic inflammatory disease, urinary tract infections, skin and soft tissue infections and used for surgical prophylaxis, reducing or eliminating signs and symptoms of infection. Cefmetazole has a low frequency of adverse effects, and a side effect profile similar to that of other cephamycins. Adverse effects following overdosage have included nausea, vomiting, epigastric distress, diarrhea, and convulsions.

Cefpiramide or SM-1652 (sodium 7-[D(-)-alpha-(4-hydroxy-6-methylpyridine-3-carboxamido)-alpha-(4-hydroxyphenyl)acetamido]-3-[(1-methyl-1H-tetrazol-5-yl) thiomethyl]-3-cephem-4-carboxylate) is a semisynthetic cephalosporin derivative with a broad spectrum of antibacterial activity. This antibiotic has been reported to have potent in vitro and in vivo antibacterial activities against gram-positive and -negative bacteria.

Cefotiam is a third generation beta-lactam cephalosporin antibiotic. It has broad spectrum activity against Gram positive and Gram negative bacteria. It does not have activity against Pseudomonas aeruginosa. The bactericidal activity of cefotiam results from the inhibition of cell wall synthesis via affinity for penicillin-binding proteins (PBPs).

Cefmenoxime is a semisynthetic beta-lactam cephalosporin antibiotic with activity similar to that of cefotaxime. Like other 'third-generation' cephalosporins it is active in vitro against most common Gram-positive and Gram-negative pathogens, is a potent inhibitor of Enterobacteriaceae (including beta-lactamase-producing strains), and is resistant to hydrolysis by beta-lactamases. Cefmenoxime has a high rate of clinical efficacy in many types of infection and is at least equal in clinical and bacteriological efficacy to several other cephalosporins in urinary tract infections, respiratory tract infections, postoperative infections and gonorrhoea. The bactericidal activity of cefmenoxime results from the inhibition of cell wall synthesis via affinity for penicillin-binding proteins (PBPs). Cefmenoxime is stable in the presence of a variety of b-lactamases, including penicillinases and some cephalosporinases. Cefmenoxime is marketed in Japan under the brand name Bestron, indicated for the treatment of otitis externa, otitis media, and sinusitis. Cefmenoxime hydrochloride was approved by the U.S. Food and Drug Administration (FDA) on Dec 30, 1987. It was developed and marketed as Cefmax®, but it has being discontinued.