Chlortetracycline (trade name Aureomycin, Lederle) is a tetracycline antibiotic, the first tetracycline to be identified. It was discovered in 1945 by Benjamin Minge Duggar working at Lederle Laboratories under the supervision of Yellapragada Subbarow. Duggar identified the antibiotic as the product of an actinomycete he cultured from a soil sample collected from Sanborn Field at the University of Missouri. The organism was named Streptomyces aureofaciens and the isolated drug, Aureomycin, because of their golden color. Chlortetracycline inhibits cell growth by inhibiting translation. It binds to the 16S part of the 30S ribosomal subunit and prevents the amino-acyl tRNA from binding to the A site of the ribosome. In veterinary medicine, chlortetracycline is commonly used to treat conjunctivitis in cats.

Rifamycin SV is a derivative of antibiotic rifamycin B (the natural fermentation product of S. mediterranei broths). The primary target of rifampicin on whole bacteria is the synthesis of RNA. Rifamycin belongs to the ansamycin class of antibacterial drugs and acts by inhibiting the beta subunit of the bacterial DNA-dependent RNA polymerase, blocking one of the steps in DNA transcription. This results in inhibition of bacterial synthesis and consequently growth of bacteria. Rifampicin exhibits bactericidal activity on Gram-positive and Gram-negative bacteria and on mycobacteria. Rifamycin SV MMX® (AEMCOLO), a non-absorbable rifamycin antibiotic formulated using the multi-matrix system, was designed to exhibit its pharmacological action on the distal small intestine and colon. AEMCOLO is indicated for the treatment of travelers’ diarrhea (TD) caused by non-invasive strains of Escherichia coli in adults.

Ombitasvir (ABT-267) is an antiviral drug for the treatment of hepatitis C virus (HCV) infection. Ombitasvir is a potent inhibitor of the hepatitis C virus protein NS5A, has favorable pharmacokinetic characteristics and is active in the picomolar range against genotype 1 - 6. In 2015, it was approved by FDA for use in combination with paritaprevir, ritonavir and dasabuvir in the product Viekira Pak for the treatment of HCV genotype 1.

Daclatasvir (BMS-790052) is a direct-acting antiviral agent against Hepatitis C Virus (HCV) used for the treatment of chronic HCV genotype 3 infection. Daclatasvir prevents RNA replication and virion assembly by binding to NS5A, a nonstructural phosphoprotein encoded by HCV. Binding to the N-terminus of the D1 domain of NS5A prevents its interaction with host cell proteins and membranes required for virion replication complex assembly.

Dasabuvir is a non-nucleoside inhibitor of the hepatitis C virus (HCV) NS5B palm polymerase inhibitor. It is used in the treatment of adult patients with chronic hepatitis C virus infection in combination with ombitasvir, paritaprevir, and ritonavir as the combination product Viekira Pak. Viekira PAK combines three direct-acting antiviral agents with distinct mechanisms of action and non-overlapping resistance profiles to target HCV at multiple steps in the viral lifecycle. Dasabuvir is extensively evaluated in large clinical trials and shown excellent sustained virological response among hepatitis C virus genotype1 patient population in combination with other oral direct acting antivirals, with good safety profile and tolerance.

Paritaprevir is a potent inhibitor of the NS3/4A protease that rapidly and consistently suppresses HCV. Paritaprevir is metabolized by the Cytochrome P450 isoform 3A (CYP3A); therefore, ritonavir was used concurrently to increase plasma concentrations and to prolong the half-life of this agent allowing for once-daily dosing. Several antiviral regimens combining paritaprevir with other agents have shown impressive results, tolerable side effects, and importantly, provided support of ‘all-oral’ interferon-free regimens against HCV. Paritaprevir monotherapy is discontinued now but paritaprevir is used as a component of Viekira Pak and Technivie for the treatment of patients with genotype 1 chronic hepatitis C virus (HCV) infection.

Simeprevir is a hepatitis C virus (HCV) NS3/4A protease inhibitor approved for the treatment of Chronic Hepatitis C (genotype 1 and 4). Inhibiting NS3/4A, simeprevir blocks viral replication. In in vitro assays simeprevir was potent against HCV genotype 1a and 1b. Simeprevir must not be administered as monotherapy and should only be prescribed with both peginterferon alfa and ribavirin.

Boceprevir (trade name Victrelis) is first-generation, selective, small molecule inhibitor of the non-structural serine protease (NS3) and NS4A polypeptide complex (NS3/NS4A) and is a direct acting antiviral drug against the hepatitis C virus. It is indicated the treatment of chronic hepatitis C (CHC) genotype 1 infection, in combination with peginterferon alfa and ribavirin, in adult patients (18 years of age and older) with compensated liver disease, including cirrhosis, who are previously untreated or who have failed previous interferon and ribavirin therapy. Boceprevir is not approved as a monotherapy. Upon administration, boceprevir reversibly binds to the active center of the HCV NS3/NS4A and prevents NS3/NS4A protease-mediated polyprotein maturation. This disrupts the processing of viral proteins and the formation of a viral replication complex, which inhibits viral replication in HCV genotrype 1-infected host cells. NS3, a serine protease, is essential for the proteolytic cleavages within the HCV polyprotein and plays a key role during HCV viral RNA replication. NS4A is an activating factor for NS3.

Telaprevir (marketed under the brand names Incivek and Incivo) is a direct-acting antiviralagent against the hepatitis C virus (HCV). It is a hepatitis C virus NS3/4A protease inhibitor indicated for the treatment of genotype 1 chronic hepatitis C (CHC) in adult patients with compensated liver disease, including cirrhosis, who are treatment-naïve or who have been previously treated with interferon-based treatment, including prior null responders, partial responders, and relapsers in combination with peginterferon alfa and ribavirin. Telaprevir is not used as a monotherapy. It is necessary for the proteolytic cleavage of the HCV encoded polyprotein into mature forms of the NS4A, NS4B, NS5A and NS5B proteins and essential for viral replication. It belongs to the chemical class of alpha-ketoamids and binds to NS3/4A in a covalent but reversible manner.

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.