Penicillin G, also known as benzylpenicillin, is a penicillin derivative commonly used in the form of its sodium or potassium salts in the treatment of a variety of infections. It is effective against most gram-positive bacteria and against gram-negative cocci. It is administered intravenously or intramuscularly due to poor oral absorption. Penicillin G may also be used in some cases as prophylaxis against susceptible organisms. Microbiology Penicillin G is bactericidal against penicillin-susceptible microorganisms during the stage of active multiplication. It acts by inhibiting biosynthesis of cell-wall mucopeptide. It is not active against the penicillinase-producing bacteria, which include many strains of staphylococci. Penicillin G is highly active in vitro against staphylococci (except penicillinase-producing strains), streptococci (groups A, B, C, G, H, L and M), pneumococci and Neisseria meningitidis. Other organisms susceptible in vitro to penicillin G are Neisseria gonorrhoeae, Corynebacterium diphtheriae, Bacillus anthracis, clostridia, Actinomyces species, Spirillum minus, Streptobacillus monillformis, Listeria monocytogenes, and leptospira; Treponema pallidum is extremely susceptible. Adverse effects can include hypersensitivity reactions including urticaria, fever, joint pains, rashes, angioedema, anaphylaxis, serum sickness-like reaction.

Faropenem medoxomil is an ester prodrug derivative of the beta-lactam antibiotic faropenem. The prodrug form of faropenem offers dramatically improved oral bioavailability and leads to higher systemic concentrations of the drug. Faropenem medoxomil is a broad-spectrum antibiotic that is highly resistant to beta-lactamase degradation. It was under development for the treatment of acute bacterial sinusitis, community-acquired pneumonia, acute exacerbation of chronic bronchitis, and uncomplicated skin and skin structure infections.

Doripenem is a synthetic carbapenem that has broad antibacterial potency against aerobic and anaerobic gram-positive and gram-negative bacteria. Doripenem is structurally related to beta-lactam antibiotics and shares the bactericidal mode of action of other β-lactam antibiotics by targeting penicillin-binding proteins (PBPs) to inhibit the biosynthesis of the bacterial cell wall. Doripenem is resistant to hydrolysis by most β-lactamases and is resistant to inactivation by renal dehydropeptidases. Doripenem has many similarities to the other carbapenems, as well as some important differences, such as greater potency against Pseudomonas aeruginosa. It was found to be similar to comparator agents. The most common adverse effects related to doripenem therapy were headache, nausea, diarrhea, rash, and phlebitis.

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.

Cefonicid is a semi-synthetic broad-spectrum cephalosporin antibiotic resistant to beta-lactamases. Similarly to other cephalosporins, cefonicid exerts its antibacterial activity through the inhibition of the bacterial cell-wall synthesis. Its in vitro and in vivo activity against a wide range of Gram-positive and Gram-negative microorganisms is documented.

Ceforanide is a new cephalosporin with a longer elimination half-life than any currently available cephalosporin. Its activity is very similar to that of cefamandole, a second-generation cephalosporin, except that ceforanide is less active against most gram-positive organisms. The bactericidal activity of ceforanide results from the inhibition of cell wall synthesis via affinity for penicillin-binding proteins (PBPs). Ceforanide is primarily indicated in conditions like bone and joint infection, endocarditis, respiratory tract infections, skin infections, surgical infections, urinary tract infection. Rash and pruritus, and nausea, vomiting and other mild gastrointestinal side effects were noted in a few of the subjects but were mild and transient.