ABSTRACT
In the relatively short history of specific antiviral chemotherapy the first drug to receive approval for clinical use was a halogenated pyrimidine. This chapter discusses the various antiviral agents in turn with attention being paid primarily to their molecular mechanisms of action, their effectiveness in vivo and in vitro, and their clinical status and toxicity. Iododeoxyuridine (IUdR) merits the major portion of the discussion, while other drugs are considered primarily in relation to this agent. The lack of cross resistance of IUdR resistant virus to trifluorothymidine also suggests that the loss of ability to induce thymidine kinase by the virus is not the primary mechanism of virus IUdR resistance. Iododeoxycytidine (ICdR) is similar in structure to IUdR except that an amino group replaces the hydroxyl group at the fourth position on the pyrimidine ring. Bromdeoxyuridine (BUdR) is close resemblance to IUdR. However, infectious virus production is reduced less by BUdR than by IUdR.
