How Do VZV Antivirals Work?

Varicella-Zoster virus (VZV) antivirals are used in the treatment of both varicella and zoster infections. VZV is also called human herpesvirus 3. The replication of VZV in infected cells can be blocked effectively by the administration of antiviral agents. VZV antiviral drugs get incorporated into viral DNA preventing further synthesis and viral replication.

The primary infection of VZV is varicella commonly known as chickenpox, and the reactivation of VZV - causes zoster or herpes zoster commonly known as shingles. VZV is highly contagious and transmitted predominantly by airborne droplet infection.

Acyclovir is active against most herpes viruses and is the standard therapeutic agent for the treatment of VZV infections. Acyclovir is converted into acyclovir monophosphate by the 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 virus DNA polymerase and prevents viral DNA synthesis and virus replication.

VZV antivirals are used to treat varicella and zoster caused by VZV.

• Oral administration of acyclovir is recommended for varicella in at-risk patients and zoster disease in immunocompetent patients.
• Intravenous administration of acyclovir is recommended for severe VZV infections, especially in immunodeficiency patients.

Side effects of VZV antivirals may 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)
• Swelling and pain in the joints

Rare but serious side effects of VZV antivirals may include:

• Anaphylaxis (life-threatening allergic reactions)
• Nephrotoxicity
• 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)

The information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Generic and brand names of VZV antiviral include:

• Acyclovir (Zovirax)