Antiviral therapy: current concepts and practices

Abstract

Drugs capable of inhibiting viruses in vitro were described in the 1950s, but real progress was not made until the 1970s, when agents capable of inhibiting virus-specific enzymes were first identified. The last decade has seen rapid progress in both our understanding of antiviral therapy and the number of antiviral agents on the market. Amantadine and ribavirin are available for treatment of viral respiratory infections. Vidarabine, acyclovir, ganciclovir, and foscarnet are used for systemic treatment of herpesvirus infections, while ophthalmic preparations of idoxuridine, trifluorothymidine, and vidarabine are available for herpes keratitis. For treatment of human immunodeficiency virus infections, zidovudine and didanosine are used. Immunomodulators, such as interferons and colony-stimulating factors, and immunoglobulins are being used increasingly for viral illnesses. While resistance to antiviral drugs has been seen, especially among AIDS patients, it has not become widespread and is being intensely studied. Increasingly, combinations of agents are being used: to achieve synergistic inhibition of viruses, to delay or prevent resistance, and to decrease dosages of toxic drugs. New approaches, such as liposomes carrying antiviral drugs and computer-aided drug design, are exciting and promising prospects for the future.

Cytomegalovirus Preemptive Therapy with Ganciclovir in Renal Transplant Patients Treated with OKT3

“…Ganciclovir inhibits viral replication and its efficiency depends on its commencement [18], Studies carried out on the murine CMV models have demonstrated that the drugs which most enhance reactivation of latent viruses are antilymphocvtic globulins and steroids, followed by azathioprine and cyclophosphamide [19], Although cy closporine is not able to reactivate latent viruses, it inhib its the cytotoxic CMV-specific T-cell response, which is a major defense against viral infection. In this way, sequen tial therapies based on OK.T3, prednisone, azathioprine and cyclosporine, as is our case, enhance the risk of symp tomatic infections.…”

Murine cytomegalovirus induces expression and enzyme activity of cellular dihydrofolate reductase in quiescent cells.

“…Treatment options for HCMV diseases remain limited and currently available therapies have significant toxicity (Bean, 1992). Moreover, clinically isolated HCMV strains that are resistant to the conventional drugs are becoming increasingly common (Baldanti et al, 1996 ;Chou et al, 1995).…”

Recombinant Mouse β-Defensin 3 Protects against Coxsackievirus B3-Induced Myocarditis in Mice

“…Some studies have supported a role for both immunoregulatory and antiviral therapies in the treatment of myocarditis. Until now, few effective drugs have been available to treat the disease, and severe cases have a poor prognosis without heart transplantation [11,12]. To treat viral myocarditis, ribavirin (RB) has been found to exhibit potent antiviral properties vital for the clinical treatment of viral diseases [13]; however, its use remains controversial because of its questionable efficacy, side effects, and high cost.…”