Sulopenem is a thiolanylthiopenem derivative patented by American multinational pharmaceutical corporation Pfizer Inc as an antibiotic with broad-spectrum antibacterial activity against most gram-positive and gram-negative bacteria. Sulopenem showed concentration-dependent bactericidal activities against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, and Acinetobacter calcoaceticus. Morphological observation using a phase-contrast microscope revealed that sulopenem induced spherical cell formation with E. coli and K. pneumoniae at lower concentrations and bacteriolysis at higher concentrations. Therapeutic efficacies of sulopenem against systemic infections in mice were almost equal to those of imipenem against Streptococcus pneumoniae.

Sarecycline (SC1401, WC3035) is a novel, once-daily, tetracycline-derived compound being developed by Paratek Pharmaceuticals and Allergan (previously Actavis) for use in the treatment of acne and rosacea. In preclinical studies, Sarecycline possesses favorable anti-inflammatory activity, plus narrow-spectrum antibacterial activity relative to other tetracycline-derived molecules. Sarecycline has been used in Phase III clinical trials studying the treatment of Acne Vulgaris. The primary objective was to evaluate the efficacy and safety of oral Sarecycline 1.5 mg/kg per day compared to placebo in treating inflammatory acne lesions in subjects with moderate to severe acne. Sarecycline was statistically significantly superior to placebo with respect to primary efficacy endpoints. The most common adverse events (>2%) reported in the sarecycline group were nausea (3.2%), nasopharyngitis (2.8%), and headache (2.8%). The rate of discontinuation due to adverse events among sarecycline-treated patients in the two studies combined was 1.4%.

Delafloxacin (CAS registry number 189279-58-1) was described as WQ-3034 by Wakunaga Pharmaceutical Co., Ltd., Osaka & Hiroshima, Japan. It was first licensed in 1999 to Abbott Park, IL, and further developed as ABT-492. Delafloxacin (Baxdela), a fluoroquinolone antibiotic, is currently being developed by Melinta Therapeutics. It is a novel investigational fluoroquinolone in development for the treatment of uncomplicated gonorrhea, and acute bacterial skin and skin structure infections. Delafloxacin shows MICs remarkably low against Gram-positive organisms and anaerobes and similar to those of ciprofloxacin against Gram-negative bacteria. It remains active against most fluoroquinolone-resistant strains, except enterococci. Its potency is further increased in acidic environments (found in many infection sites). Delafloxacin is active on staphylococci growing intracellularly or in biofilms. Delafloxacin is a dual-targeting fluoroquinolone, capable of forming cleavable complexes with DNA and topoisomerase IV or DNA gyrase and of inhibiting the activity of these enzymes in both Gram-positive and Gram-negative bacteria. On Oct 24, 2016, Melinta Therapeutics Submitted Baxdela New Drug Application for hospital-treated skin infections.

Ceftolozane is a novel a cephalosporin-class antibacterial drug. In combination with a beta-lactamase inhibitor tazobactam (ZERBAXA, ceftolozane/tazobactam ) ceftolozane, is currently indicated for the treatment of the adult patients with complicated intra-abdominal infections caused by designated Gram-negative and Gram-positive microorganisms and complicated urinary tract infections caused by certain Gram-negative bacteria, including those caused by multi-drug resistant Pseudomonas aeruginosa. To reduce the development of drug-resistant bacteria and maintain the effectiveness of ZERBAXA and other antibacterial drugs, ZERBAXA should be used only to treat infections that are proven or strongly suspected to be caused by susceptible bacteria. Safety and effectiveness in pediatric patients have not been established.

Fidaxomicin (trade names Dificid, Dificlir in Europe) is the first in a new class of narrow spectrum macrocyclic antibiotic drugs indicated for treatment of Clostridium difficile-associated diarrhea. Lipiarmycin (fidaxomicin), a metabolite of Actinoplanes deccanensis nov. sp. was first isolated in pure form in 1970s and was considered as antibiotic from its chemical and physico-chemical characteristics. It demonstrated high activity against Gram-positive bacteria, including strains resistant to the medically important antibiotics and protected mice experimentally infected with Streptococcus haemolyticus. Fidaxomicin is non-systemic, meaning it is minimally absorbed into the bloodstream, it is bactericidal, and it has demonstrated selective eradication of pathogenic Clostridium difficile with minimal disruption to the multiple species of bacteria that make up the normal, healthy intestinal flora. Although the exact mechanism of action has yet to be fully elucidated, fidaxomicin may bind to and inhibit bacterial DNA-dependent RNA polymerase, thereby inhibiting the initiation of bacterial RNA synthesis. When orally administered, this agent is minimally absorbed into the systemic circulation, acting locally in the gastrointestinal tract. Fidaxomicin appears to be active against pathogenic Gram-positive bacteria, such as clostridia, enterococci, and staphylococci, but does not appear to be active against other beneficial intestinal bacteria. The maintenance of normal physiological conditions in the colon can reduce the probability of Clostridium difficile infection recurrence. It is marketed by Cubist Pharmaceuticals after acquisition of its originating company Optimer Pharmaceuticals.

Besifloxacin (INN/USAN) is a fourth-generation fluoroquinolone antibiotic. The marketed compound is Besifloxacin hydrochloride. It was developed by SSP Co. Ltd., Japan, and designated SS734. SSP licensed U.S. and European rights to SS734 for ophthalmic use to InSite Vision Incorporated in 2000. InSite Vision developed an eye drop formulation (ISV-403) and conducted preliminary clinical trials before selling the product and all rights to Bausch & Lomb in 2003. Besifloxacin is indicated in the treatment of bacterial conjunctivitis caused by sensitive germs, as well as in the prevention of infectious complications in patients undergoing laser therapy for the treatment of cataracts. Besifloxacin inhibits bacterial DNA gyrase and topoisomerase IV and has a broad spectrum of bactericidal activity against strains commonly isolated from patients with bacterial conjunctivitis. In addition, some exploratory in vitro data suggest that Besifloxacin inhibits cytokine formation in human corneal epithelial cells and monocytes, but the relevance of this finding to therapeutic efficacy is unknown.

TELAVANCIN (VIBATIV®) is a lipoglycopeptide antibacterial that is a synthetic derivative of vancomycin. It exerts concentration-dependent, bactericidal activity against Gram-positive organisms in vitro. TELAVANCIN (VIBATIV®) inhibits cell wall biosynthesis by binding to late-stage peptidoglycan precursors, including lipid II. It also binds to the bacterial membrane and disrupts membrane barrier function. TELAVANCIN (VIBATIV®) is indicated for the treatment of adult patients with complicated skin and skin structure infections caused by susceptible isolates of the following Gram-positive microorganisms: Staphylococcus aureus (including methicillin-susceptible and -resistant isolates), Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus anginosus group (includes S. anginosus, S. intermedius, and S. constellatus), or Enterococcus faecalis (vancomycin-susceptible isolates only). It is also indicated for the treatment of adult patients with hospital-acquired and ventilator-associated bacterial pneumonia (HABP/VABP), caused by susceptible isolates of Staphylococcus aureus (both methicillin-susceptible and -resistant isolates). It should be reserved for use when alternative treatments are not suitable.

Daptomycin is a lipopeptide antibiotic used in the treatment of systemic and life-threatening infections caused by Gram-positive organisms. Daptomycin has a distinct mechanism of action, disrupting multiple aspects of bacterial cell membrane function. It inserts into the cell membrane in a phosphatidylglycerol-dependent fashion, where it then aggregates. The aggregation of daptomycin alters the curvature of the membrane, which creates holes that leak ions. This causes rapid depolarization, resulting in a loss of membrane potential leading to inhibition of protein, DNA, and RNA synthesis, which results in bacterial cell death. Daptomycin is bactericidal against Gram-positive bacteria only. It has proven in vitro activity against enterococci (including glycopeptide-resistant enterococci (GRE)), staphylococci (including methicillin-resistant Staphylococcus aureus), streptococci, corynebacteria and stationary-phase Borrelia burgdorferi persisters.

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.

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.