Future prospects in antiviral therapy

Antiviral agents in hepatitis B virus transfected cell lines: inhibitory and cytotoxic effect related to time of treatment

The antiviral and cytotoxic effects of ara-arabinoside monophosphate, 2',3', dideoxy-cytidine, ganciclovir, 9-2(-phosphonylmethoxyethyl) adenine, 2',3'-dideoxy-3'-thiacytidine and recombinant interferon-alpha were studied using two human hepatitis B virus transfected hepatoma cell lines, HepG2 2.2.15 and HB 611. After 9 days of exposure, starting on day 3 after seeding, inhibition of extracellular HBV-DNA expressed as ID50 was in the 0.1-1.0 microM range for 2',3'-dideoxy-3'-thiacytidine and 9-2(-phosphonylmethoxyethyl) adenine and > 10 microM for dideoxy-cytidine, ara-arabinoside monophosphate and ganciclovir in both cell lines. At 2.500 U/ml recombinant interferon-alpha showed less than 20% inhibition in both cell lines. The HBV-DNA inhibitory effects of 2',3'-dideoxy-3'-thiacytidine and 9-2(-phosphonylmethoxyethyl) adenine were also investigated after 1 and 3 days of exposure. In that setting ID50's were 10 and 3.3 microM for 2',3'-dideoxy-3'-thiacytidine and > 100 and 30 microM for 9-2(-phosphonylmethoxyethyl) adenine, respectively. No major inhibitory effect on hepatitis B surface antigen and hepatitis B e antigen secretion was observed for any agent in this study, except for 9-2(-phosphonylmethoxyethyl) adenine in HB 611 cells. Cytotoxicity measured by inhibition of [3H-methyl] deoxythymidine incorporation and expressed as CD50 on day 4 was in the 10-100 microM range for ara-arabinoside monophosphate; in the 100-1000 microM range for 9-2(-phosphonylmethoxyethyl) adenine, ganciclovir and dideoxy-cytidine; and > 1000 microM for 2',3'-dideoxy-3'-thiacytidine.(ABSTRACT TRUNCATED AT 250 WORDS)

Antiviral drugs: present status and future prospects

1. There is a limited number of antiviral drugs available for therapy. Many investigations and new analytical techniques have unraveled the development and progression of a viral infection. Nowadays there is a good understanding of the multiplication cycle of viruses, including the human immunodeficiency virus. 2. In this article the currently available antiviral drugs are presented arranged by their mode of action that can be understood by the multiplication cycle of the virus. 3. Clinical use and side-effects are discussed as well as place in current therapy. Some attention is paid on promising investigational antivirals.