How Do HSV Antivirals Work?

Herpes simplex virus (HSV) antivirals are used to treat herpes simplex virus 1 and 2 (HSV-1 and HSV-2). Acyclovir is the antiviral most commonly used to treat HSV infections. It works by inhibiting DNA synthesis and therefore prevents replication of the virus. HSV-1 is transmitted by oral-to-oral contact, mainly causes oral herpes known as cold sores, and may also cause genital herpes. HSV-2 is a sexually transmitted disease that causes genital herpes. Herpes infections are highly contagious; oral and genital herpes is usually asymptomatic, and if symptomatic, painful blisters or ulcers appear at the site of infection. HSV-2 infection increases the risk of acquiring and transmitting human immunodeficiency virus infection.

Acyclovir is converted into acyclovir monophosphate by viral thymidine kinase enzyme, which is then converted into acyclovir triphosphate (ACV-TP) by the host cell kinases. The formed ACV-TP competitively inhibits and inactivates HSV DNA polymerase and prevents viral DNA synthesis and replication of the virus.

HSV antivirals are used to treat HSV-1 and HSV-2 infections.

Side effects associated with HSV antivirals include:

• Nausea and vomiting
• Diarrhea
• Constipation
• Sore throat
• Headache
• Dizziness
• Fatigue
• Abdominal pain
• Easy bruising or bleeding
• Alopecia (loss of hair)
• Anorexia (loss of appetite)
• Anaphylaxis (life-threatening allergic reactions)
• Nephrotoxicity (function disability because of the toxic nature of the drug)
• Neurological disorders
• Hepatitis (inflammation of the liver)
• Toxic epidermal necrolysis (a life-threatening skin condition characterized by widespread redness and death of skin tissue)
• Stevens-Johnson syndrome (severe skin reaction where the skin and mucous membranes are damaged)
• Thrombotic thrombocytopenic purpura (formation of blood clots in small blood vessels and is characterized as purple discoloration on the skin)

Generic and brand names of HSV antiviral drugs include:

• Acyclovir (Zovirax)
• Valacyclovir (Valtrex)