Antiviral Agents for Herpes Viruses

HPI SL is a 35-year-old female lawyer who is complaining of itching and burning in her genital area. She states that she has had these symptoms in the past, particularly when she is under a lot of stress. 

Herpes simplex virus is divided into HSV-1 and HSV-2. Genital herpes is usually caused by HSV-2, whereas oral herpes is caused by HSV-1. Primary herpes refers to the first outbreak of infection, whereas recurrent herpes refers to subsequent infections. With each outbreak, patients typically experience symptoms 2 to 10 days after the initial infection. Symptoms may include a prodrome of burning or itching, followed by the appearance of blisters and open sores within a few days. Other symptoms such as fever, headache, muscle aches, painful urination, or vaginal discharge are also common. In general, recurrent outbreaks are usually mild and shorter in duration. 

Because viral replication occurs prior to the onset of symptoms, initiation of early therapy is imperative for optimum 

Acyclovir is an acyclic guanosine derivative that requires three phosphorylation steps for activation. Conversion to the monophosphate is carried out by the virus thymidine kinase, and conversion to the di- and triphosphate is carried out by host kineases. The active nucleotide triphosphate inhibits viral replication by competing with the viral deoxy-GTP for the viral DNA polymerase. Thus, acyclovir triphosphate is inserted into the growing viral DNA, leading to irreversible chain termination. Reduced susceptibility to acyclovir is due to altered viral thymidine kinase. Because the MOA of ganciclovir is similar to that of acyclovir, HSV that is resistant to acyclovir is also resistant to ganciclovir. 

Case Conclusion SL is experiencing a recurrent genital herpes outbreak. The treatment of choice is either acyclovir or one of the acyclovir analogues. The duration of symptoms may be shortened because SL was able to identify and seek treatment for her outbreak early. 

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