antibioticsbooks

Anti-Cytomegalovirus
Agents
33
Agents: ganciclovir, valganciclovir, foscarnet,
cidofovir
The common virus known as cytomegalovirus
(CMV) causes infections that are usually asymptomatic
in immunocompetent patients but can
be devastating in immunocompromised patients.
Approximately 60% of Americans become seropositive
for CMV by adulthood, and infection is lifelong.
If a patient becomes immunocompromised, the
infection can reactivate and the patient will need
pharmacotherapy. Anti-cytomegalovirus agents
work by preventing viral replication. They also all
have appreciable toxicity that must be respected
and monitored.
Mechanisms of Action
Ganciclovir is a nucleoside analogue that, after
phosphorylation, is integrated into viral DNA
by DNA polymerase, halting viral replication.
Valganciclovir is a pro-drug of ganciclovir. Cidofovir
is a nucleotide analogue that has a similar mechanism
to ganciclovir.
Foscarnet is a pyrophosphate analogue that
acts as a noncompetitive inhibitor of the DNA and
RNA polymerases of multiple viruses.