| REVIEW ARTICLE
|Year : 2000 | Volume
| Issue : 6 | Page : 330-338
Antiviral drugs against herpes infections
Vajpayee Madhu, Malhotra Neena
Several new and promising antiviral drugs have been approved which allow better options to control infections caused by herpes virus. Vidarabine has been the earliest available drug against herpes simplex (HSV) and varicella zoster (VZV), but is an agent that is rarely used at present. Acyclovir has replaced vidarabine in treating herpes infections in immunocompetent and immuno compromised patients. The low oral bioavailability of acyclovir, as well as emergence of drug resistant strains have stimulated efforts towards development of newer compounds for treatment of herpes infection. These include penciclovir and its oral prodrug famciclovir and the oral prodrug form of acyclovir, valacyclovir. These drugs are dependent on virus encoded thymidine kinase (TK) for their intracellular activation (phosphorylation) and, upon conversion to their triphosphate form which act as inhibitors/alternative substrate of viral DNA polymerase. Therefore resistance of these drugs may occur for virus mutants that are TK-deificient. Newer drugs as Sorivudine which is a nucleoside analogue has been pursued in treating herpes infections. Foscarnet, which does not require any previous metabolism to interact with viral DNA polymerase is useful in clinical settings when TK deficient mutant strains emerge. Cidofovir, an acyclic nucleoside phosphonate is yet another available drug to which TK deficient strains are sensitive. This review describes these currently available antiviral drugs against herpes virus, some approved and others under clinical evaluation for approval.
Source of Support: None, Conflict of Interest: None