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 μM range for 2′,3′-dideoxy-3′-thiacytidine and 9-2(-phosphonylmethoxyethyl) adenine and >10 μM 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 t
