Therapeutic potential of phosphonylmethoxyalkylpurines and -pyrimidines as antiviral agents.

Phosphonylmethoxyalkylpurines and -pyrimidines offer great promise for both topical and systemic treatment of various DNA virus and retrovirus infections: HPMPA for the treatment of adeno-, herpes- and poxvirus infections, HPMPC for the treatment of herpesvirus (in particular CMV) infections, and PMEA and PMEDAP for the treatment of retrovirus (i.e. HIV) infections. The efficacy of HPMPA, HPMPC, PMEA and PMEDAP has been demonstrated in various animal model infections, and the further pursuit of their clinical potential seems fully justified. The target for the antiviral action of these compounds appears to be viral DNA synthesis, which they inhibit at a concentration which is far below the concentration required to inhibit cellular DNA synthesis.