Anti-infective therapy for viral pneumonia

The recognition of viruses as causes of pneumonia in both immunocompetent and immunocompromised hosts has expanded dramatically. The number of therapeutic agents available for treatment of these illness also has increased in the last decade. Each of these agents has demonstrated a limited therapeutic indication for treatment of viral pneumonia. Many of these agents inhibit viral DNA synthesis through actions as nucleoside analogs (such as acyclovir and ganciclovir). However, a variety of alternative mechanisms of inhibition of viral replication are used. Ribavirin, while being a nucleoside analogue, also appears to exert broad antiviral activity by a variety of enzymatic inhibitory mechanisms. Foscarnet, an inorganic pyrophosphate analogue, offers additional treatment options for herpesviruses by acting as a direct virus DNA polymerase inhibitor. The tricyclic amines amantadine and rimantadine inhibit influenza A replication by interfering with viral uncoating after cell penetration. Thus, these two agents are largely effective as prophylaxis. The search for novel antiviral drugs, such as neuraminadases inhibitors with selective influenza activity, is currently in progress.