Tiviciclovir (A188) is a nucleoside analog used in the synthesis of antiviral drugs. This acyclic guanosine analog has a potential for the treatment of hepatitis B virus. However, as with penciclovir and the related compounds acyclovir and ganciclovir, the intestinal absorption of Tiviciclovir is limited. One approach to overcome this is through synthesis of the 6-deoxy prodrug version of AM188, i.e. AM365, which has improved intestinal absorption. Following absorption, the 6-deoxyguanosine analog AM365 is converted to the corresponding anti-virally active guanosine analog, AM188, probably by the liver molybdenum hydroxylases, aldehyde oxidase and xanthine oxidase. Renal tubular secretion of AM188 involves organic anion and cation transport systems.

Famotine, 1 -(p-chlorophenoxymethyl)-3,4-dihydroisoquinoline (UK 2054), is an antiviral compound.

Fiacitabine, also known as FIAC, is a pyrimidine nucleoside, which had been in phase II clinical trilas for the treatment Cytomegalovirus infections and Herpes simplex virus infections. However, these researches have been discontinued. It was also shown the inhibitor activity of FIAC against the DNA polymerase of hepadnaviruses.

Arildone (also known as Win 38020), an antiviral agent that inhibits replication of herpes simplex virus type 2 and is capable to prevent the poliovirus-induced death in mice.

Didox is a simple, synthetic antioxidant and a ribonucleotide reductase inhibitor with activity against retroviruses. Didox inhibits retrovirus replication by depleting the deoxynucleotides obligatory for the synthesis of the proviral DNA intermediate of retrovirus replication. It also increases the radiosensitivity of cancer cells by inhibition of ribonucleotide reductase, resulting in a reduction of BCL-2 mediated resistance to apoptosis. Didox has been found to reduce the levels of oxidative injury markers in the brains of HIV patients with dementia. Didox has been evaluated in various phase I and phase II trials but Didox did not demonstrate any efficacy response in patients.

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.

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.