Acyclovir

Product description:Acyclovir is a synthetic purine analog that has antiviral activity against herpes simplex virus (HSV-1 and HSV-2) and varicella-zoster virus (VZV). Resistance of HSV and VZV to acyclovir have been reported, especially in severely immunocompromised patients such as those with advanced HIV infection. The possibility of viral resistance to acyclovir should be considered in patients who show poor clinical response to therapy.
This resistance of HSV and VZV to antiviral nucleoside analogs can result from qualitative or quantitative changes in the viral thymidine kinase (TK) or deoxyribonucleic acid (DNA) polymerase. Most of the acyclovir-resistant mutants isolated from immunocompromised patients, such as those from patients with advanced human immunodeficiency virus (HIV) infections, have been found to be TK-deficient mutants; however, other mutants involving the viral TK gene (TK-partial and TK-altered) and DNA polymerase also have been isolated. TK-negative mutants of HSV and VZV may cause severe disease in infants and immunocompromised adults.
Synonyms: Acycloguanosine; 9-[(2-Hydroxyethoxy)methyl]guanine; 2-Amino-1,9-dihydro-9-((2-hydroxyethoxy)methyl)-6H-purin-6-one 
Molecular Formula:  C8H11N5O3  
Molecular Weight:  225.21