Suramin inhibits in vitro infection by duck hepatitis B virus, Rous sarcoma virus, and hepatitis delta virus.

Suramin blocked in vitro infection by duck hepatitis B virus, a hepadnavirus, and Rous sarcoma virus, a retrovirus. Although suramin was able to inhibit the virus-encoded reverse transcriptase activities of these two viruses, this inhibition did not appear to account for the anti-viral effect of the drug. In particular, suramin was unable to block synthesis within cells of full-length viral DNAs when added subsequent to infection. The results are consistent with the hypothesis that suramin acted by blocking virus uptake or uncoating. As further support of this hypothesis, we found that suramin also blocked infection by hepatitis delta virus, an RNA virus that is not known to employ reverse transcriptase during the initiation of infection.