Can Inhibit the Ability of Viruses to Replicate

Acyclovir is useful in the treatment of herpes. Oral herpes is caused by the herpes simplex virus 1 (HSV-1), and genital herpes is caused by the herpes simplex virus 2 (HSV-2). More than 90 percent of the world s population is infected with the oral herpes virus, though there are many infected people who do not exhibit symptoms. Genital herpes is the most prevalent nondurable sexually transmitted disease. In the United States, there are about 30 million people infected with HSV-2 and an estimated 200,000 to 500,000 new cases each year. 

Before a nucleoside, such as guanosine, can be incorporated into RNA or DNA, it must be activated by having three phosphate groups attached to it. 

Viruses are much smaller than bacteria and many times smaller than animal cells. (Notice the small dot representing the virus.) The smallest of all pathogens, viruses consist mostly of nucleic acids enclosed in a protein coat. 

Acyclovir (Zovirax) is a derivative of the nucleoside deoxyguano-sine, and zidovudine (AZT) is a derivative of the nucleoside deoxythymidine. 

A virus is so much simpler than a bacterium. Why then are viruses so much more difficult to target with chemotherapeutics  

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