Caspofungin is an echinocandin antifungal drug, which is approved and is sold under the brand worldwide name cancidas. Caspofungin inhibits the synthesis of beta (1,3)-D-glucan, an essential component of the cell wall of susceptible Aspergillus species and Candida species. Beta (1,3)-D-glucan is not present in mammalian cells. Cancidas is indicated for the treatment of candidemia and the following candida infections: intra-abdominal abscesses, peritonitis, and pleural space infections in adult and pediatric patients. Also is indicated for the treatment of esophageal candidiasis in adult and pediatric patients and for the treatment of invasive aspergillosis in adult and pediatric patients, but has not been studied as initial therapy for invasive aspergillosis.

Ertapenem is a carbapenem antibiotic marketed by Merck as Invanz. The bactericidal activity of ertapenem results from the inhibition of cell wall synthesis and is mediated through ertapenem binding to penicillin binding proteins (PBPs). In Escherichia coli, it has strong affinity toward PBPs 1a, 1b, 2, 3, 4 and 5 with preference for PBPs 2 and 3. Ertapenem has been designed to be effective against Gram-negative and Gram-positive bacteria. The most common drug-related adverse experiences in patients treated with INVANZ, including those who were switched to therapy with an oral antimicrobial, were diarrhea (5.5%), infused vein complication (3.7%), nausea (3.1%), headache (2.2%), vaginitis in females (2.1%), phlebitis/thrombophlebitis (1.3%), and vomiting (1.1%). The coadministration with probenecid to extend the half-life of ertapenem is not recommended.

Lopinavir (ABT-378) is an antiretroviral of the protease inhibitor class. It is used against HIV infections as a fixed-dose combination with another protease inhibitor, ritonavir, under the trade names Kaletra.

Linezolid is an antibiotic used for the treatment of infections caused by Gram-positive bacteria that are resistant to other antibiotics. Linezolid appears to be unique in that it blocks the initiation of protein production. Most common adverse reactions include diarrhea, vomiting, headache, nausea, and anemia. Linezolid has the potential for interaction with adrenergic and serotonergic agents. And with monoamine oxidase inhibitors because it’s nonselective inhibitor of monoamine oxidase.

Moxifloxacin is a synthetic antibacterial agent developed by Bayer AG (initially called BAY 12-8039) for oral and intravenous administration. Moxifloxacin, a fluoroquinolone, is available as the monohydrochloride salt of 1-cyclopropyl-7-[(S,S)-2,8diazabicyclo[4.3.0]non-8-yl]-6-fluoro-8-methoxy-1,4-dihydro-4-oxo-3 quinoline carboxylic acid. Moxifloxacin is marketed worldwide (as the hydrochloride) under the brand names Avelox, Avalox, and Avalon for oral treatment. In most countries, the drug is also available in the parenteral form for intravenous infusion. Moxifloxacin is also sold in an ophthalmic solution (eye drops) under the brand names Vigamox, and Moxeza for the treatment of conjunctivitis (pink eye). Its antibacterial spectrum includes enteric Gram-(−) rods (Escherichia coli, Proteus species, Klebsiella species), Haemophilus influenzae, atypical bacteria (Mycoplasma, Chlamydia, Legionella), and Streptococcus pneumoniae, and anaerobic bacteria. It differs from earlier antibacterials of the fluoroquinolone class such as levofloxacin and ciprofloxacin in having greater activity against Gram-positive bacteria and anaerobes.

Amprenavir is an inhibitor of HIV-1 protease. Amprenavir binds to the active site of HIV-1 protease and thereby prevents the processing of viral gag and gag-pol polyprotein precursors, resulting in the formation of immature non-infectious viral particles. Amprenavir-containing combination regimens have shown virological efficacy, and have generally been well tolerated, in patients with HIV infection (primarily treatment-naive or protease inhibitor-naive). Fosamprenavir (GW433908, Lexiva, Telzir) is an oral prodrug of amprenavir, with a reduced daily pill burden. The use of protease inhibitors has also been associated with dyslipidemia and an increased risk of cardiovascular disease. Amprenavir activates Pregnane X receptor to mediate dyslipidemia.

Zanamivir, an antiviral agent, is a neuraminidase inhibitor indicated for treatment of uncomplicated acute illness due to influenza A and B virus in adults and pediatric patients 7 years and older who have been symptomatic for no more than 2 days. Zanamivir has also been shown to significantly inhibit the human sialidases NEU3 and NEU2 in the micromolar range (Ki 3.7 +/-0.48 and 12.9+/-0.07 uM, respectively), which could account for some of the rare side effects of zanamivir. The proposed mechanism of action of zanamivir is via inhibition of influenza virus neuraminidase with the possibility of alteration of virus particle aggregation and release. By binding and inhibiting the neuraminidase protein, the drug renders the influenza virus unable to escape its host cell and infect others. Zanamivir was the first neuraminidase inhibitor commercially developed. It is currently marketed by GlaxoSmithKline under the trade name Relenza as a powder for oral inhalation.

Quinupristin is an antibiotic compound and a semisynthetic derivative of pristinamycin Ia. Quinupristin is a combination of three peptide macrolactones. Quinupristin is used in combination with dalfopristin, another antibiotic, under the trade name Synercid. Synercid is indicated for treatment of complicated skin and skin structure infections caused by methicillin-susceptible Staphylococcus aureus or Streptococcus pyogenes. The mechanism of action of quinupristin is inhibition of the late phase of protein synthesis in the bacterial ribosome. Quinupristin binds to 23S rRNA within the 50S ribosomal subunit and prevents elongation of the polypeptide as well as causing incomplete chains to be released. Adverse reactions to Synercid include inflammation at infusion site, rash, nausea, vomiting and others.

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.

Dalfopristin is a pristinamycin-like component of anti-bacterial drug called Synercid which also containes quinupristin (quinupristin:dalfopristin ratio is 30:70 (w/w)). The drug was approved by FDA and used for the treatment of skin diseases caused by Staphylococcus aureus or Streptococcus pyogenes. Dalfopristin binds to the RNA of the 50S ribosomal subunit and thus inhibits the late phase of protein synthesis.