Rifaximin is a structural analog of rifampin and a non-systemic, gastrointestinal site-specific antibiotic. Rifaximin acts by inhibiting bacterial ribonucleic acid (RNA) synthesis and contributes to restore intestinal microflora imbalance. It is FDA approved for the treatment of travelers’ diarrhea, reduction in risk of overt hepatic encephalopathy (HE) recurrence and treatment of irritable bowel syndrome with diarrhea. More common side effects are: black, tarry stools; dizziness or lightheadedness; muscle spasm; rapid breathing; shortness of breath; trouble sleeping. Co-administration of cyclosporine, with XIFAXAN resulted in 83-fold and 124-fold increases in rifaximin mean Cmax in healthy subjects.

Cefuroxime is a semisynthetic, broad-spectrum, cephalosporin antibiotic. Cefuroxime is a bactericidal agent that acts by inhibition of bacterial cell wall synthesis. Cefuroxime has activity in the presence of some beta-lactamases, both penicillinases and cephalosporinases, of Gram-negative and Gram-positive bacteria. Cefuroxime has been shown to be active against most isolates of the following bacteria, both in vitro and in clinical infection: Enterobacter spp., Escherichia coli, Klebsiella spp., Haemophilus influenzae, Neisseria meningitidis, Neisseria gonorrhoeae, Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus pyogenes. Cefuroxime is indicated for the treatment of patients with septicemia, meningitis, gonorrhea, lower respiratory tract, urinary tract, skin and skin-structure, bone and joint infections caused by susceptible strains of the designated organisms.

Trimethoprim (TMP) is an antibiotic is used for the treatment of initial episodes of uncomplicated urinary tract infections due to susceptible strains of the following organisms: Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae, Enterobacter species, and coagulase-negative Staphylococcus species, including S. saprophyticus. Cultures and susceptibility tests should be performed to determine the susceptibility of the bacteria to trimethoprim. Therapy may be initiated prior to obtaining the results of these tests. Trimethoprim is rapidly absorbed following oral administration. It exists in the blood as unbound, protein-bound, and metabolized forms. Ten to twenty percent of trimethoprim is metabolized, primarily in the liver; the remainder is excreted unchanged in the urine. The principal metabolites of trimethoprim are the 1- and 3-oxides and the 3'- and 4'-hydroxy derivatives. The free form is considered to be the therapeutically active form. Approximately 44% of trimethoprim is bound to plasma proteins. Trimethoprim blocks the production of tetrahydrofolic acid from dihydrofolic acid by binding to and reversibly inhibiting the required enzyme, dihydrofolate reductase. This binding is very much stronger for the bacterial enzyme than for the corresponding mammalian enzyme

Cefazolin is a semisynthetic cephalosporin analog with broad-spectrum antibiotic action due to inhibition of bacterial cell wall synthesis. By binding to specific penicillin-binding proteins (PBPs) located inside the bacterial cell wall, cefazolin inhibits the third and last stage of bacterial cell wall synthesis. Cell lysis is then mediated by bacterial cell wall autolytic enzymes such as autolysins. Cefazolin is used to treat bacterial infections of the skin, moderately severe bacterial infections involving the lung, bone, joint, stomach, blood, and urinary tract. It is clinically effective against infections caused by staphylococci and streptococci species of Gram positive bacteria. This drug also can be used for perioperative prophylaxis.

Cephalexin is a semisynthetic cephalosporin antibiotic intended for oral administration. In vitro tests demonstrate that the cephalosporins are bactericidal because of their inhibition of cell-wall synthesis. Cephalexin has been shown to be active against most strains of the following microorganisms both in vitro: Staphylococcus aureus (including penicillinase-producing strains), Streptococcus pneumoniae (penicillin-susceptible strains), Streptococcus pyogenes, Escherichia coli, Haemophilus influenzae, Klebsiella pneumoniae, Moraxella (Branhamella) catarrhalis, Proteus mirabilis. Cephalexin is indicated for the treatment of the respiratory tract, skin and skin structure, bone and genitourinary tract infections when caused by susceptible strains of the designated microorganisms.

Dicloxacillin sodium USP is a semisynthetic antibiotic substance which resists destruction by the enzyme penicillinase (beta-lactamase). It is monosodium (2S,5R,6R)-6-[3-(2,6-dichlorophenyl)-5-methyl-4- isoxazolecarboxamido]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo [3.2.0]heptane-2-carboxylate monohydrate. Like other β-lactam antibiotics, dicloxacillin acts by inhibiting the synthesis of bacterial cell walls. It inhibits cross-linkage between the linear peptidoglycan polymer chains that make up a major component of the cell wall of Gram-positive bacteria. Dicloxacillin is administered orally via capsule form or powder for reconstitution.

Lincomycin (LINCOCIN®) is an antibiotic produced by Streptomyces lincolnensis (Streptomycetaceae family). It has been used in the treatment of staphylococcal, streptococcal, and Bacteroides fragilis infections. Lincomycin (LINCOCIN®) inhibits protein synthesis in susceptible bacteria by binding to the 50S subunits of bacterial ribosomes and preventing peptide bond formation upon transcription. It is usually considered bacteriostatic, but may be bactericidal in high concentrations or when used against highly susceptible microorganisms.

Ampicillin is a penicillin beta-lactam antibiotic. The following gram-negative and gram-positive bacteria have been shown in in vitro studies to be susceptible to ampicillin: Hemolytic and nonhemolytic streptococci, Streptococcus pneumoniae, Nonpenicillinase-producing staphylococci, Clostridium spp., B. anthracis, Listeria monocytogenes, most strains of enterococci, H. influenzae, N. gonorrhoeae, N. meningitidis, Proteus mirabilis, many strains of Salmonella, Shigella, and E. coli. Ampicillin is indicated in the treatment of bacterial meningitis, septicemia, endocarditis, urinary tract, gastrointestinal, respiratory tract infections caused by susceptible strains of the designated organisms.

Oxacillin is a penicillin beta-lactam antibiotic used in the treatment of bacterial infections caused by susceptible, usually gram-positive, organisms. The name "penicillin" can either refer to several variants of penicillin available, or to the group of antibiotics derived from the penicillins. Oxacillin has in vitro activity against gram-positive and gram-negative aerobic and anaerobic bacteria. The bactericidal activity of Oxacillin results from the inhibition of cell wall synthesis and is mediated through Oxacillin binding to penicillin binding proteins (PBPs). Oxacillin is stable against hydrolysis by a variety of beta-lactamases, including penicillinases, and cephalosporinases and extended spectrum beta-lactamases. By binding to specific penicillin-binding proteins (PBPs) located inside the bacterial cell wall, Oxacillin inhibits the third and last stage of bacterial cell wall synthesis. Cell lysis is then mediated by bacterial cell wall autolytic enzymes such as autolysins; it is possible that Oxacillin interferes with an autolysin inhibitor. Oxacillin is used in the treatment of resistant staphylococci infections. Oxacillin sodium was marketed under the trade name Bactocill.

Erythromycin cyclocarbonate (Davercin) is a first generation semi-synthetic erythromycin. It is active against Gram-positive and some Gram-negative microorganisms. Davercin shows comparable or better in vitro potency, low host toxicity and improved pharmacokinetics compared with erythromycin. It is approved for the treatment of acne, atypical pneumonia (caused by Mycoplasma pneumoniae, Chlamydia pneumoniae, Legionella pneumophila), whooping cough (treatment and prevention), urethritis (caused by Ureaplasma urealyticum and Chlamydia trachomatis), gastrointestinal infection caused by Campylobacter spp., short-term infections of the skin and soft tissues (e.g. acne, staphylococcal dermatitis). In streptococcal infections, diphtheria, gonorrhea, early syphilis in patients who are allergic to penicillin, and in the prevention of bacterial endocarditis before the planned dental procedures. Adverse effects are: nausea, vomiting, abdominal pain, diarrhea, skin allergic reactions.