Description
Zoviclovir (Acyclovir) 200 mg
Zoviclovir 200 mg is an oral tablet product containing acyclovir, a synthetic antiviral medicine used against selected herpesvirus infections. It is part of the established class of anti-herpes nucleoside analogues and is intended for systemic antiviral therapy rather than topical use.
Active Ingredient and Medicine Class
The verified active ingredient is acyclovir (also spelled aciclovir in some regions). It is a synthetic purine nucleoside analogue with activity against herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2 (HSV-2), and varicella-zoster virus (VZV). Official prescribing information describes acyclovir tablets as an oral formulation for ingestion only.
Established Medical Uses
According to official prescribing information, oral acyclovir tablets are indicated for:
- Herpes zoster (shingles)
- Genital herpes, including initial episodes and management of recurrent episodes
- Chickenpox (varicella)
Clinical studies in the label show that acyclovir can shorten the course of some herpesvirus infections when treatment is started early in the illness.
How It Works
Acyclovir is selectively activated inside infected cells by a viral enzyme called thymidine kinase. After conversion to its active triphosphate form, it interferes with viral DNA production by inhibiting viral DNA polymerase and causing premature termination of the growing viral DNA chain. This limits herpesvirus replication, but it does not eliminate latent virus from the body.
Important Safety Information
Official labeling states that acyclovir is contraindicated in people with a clinically significant hypersensitivity reaction to acyclovir, valacyclovir, or any component of the formulation. Important warnings and precautions include:
- Renal impairment and renal failure, which have been reported with acyclovir therapy
- Thrombotic thrombocytopenic purpura/hemolytic uremic syndrome in immunocompromised patients
- Severe cutaneous adverse reactions, including Stevens-Johnson syndrome, toxic epidermal necrolysis, DRESS, AGEP, and erythema multiforme
- Caution with nephrotoxic medicines, which may increase the risk of kidney-related adverse effects
- Renal dose adjustment may be required in patients with impaired kidney function
Prescribing information also notes that acyclovir is not a cure for genital herpes and that transmission of infection may still occur.
Possible Side Effects
Reported adverse effects include gastrointestinal symptoms such as nausea and diarrhea, as well as headache. More serious reactions reported in official sources include kidney problems, blood disorders such as thrombocytopenia or leukopenia, abnormal liver tests, and the serious skin reactions listed above. Rare neurologic symptoms have also been described, particularly in the setting of renal dysfunction.
Scientific Evidence
Human clinical studies and reviews have long supported acyclovir as an established treatment for herpesvirus infections, especially HSV and VZV. Reviews in PubMed describe acyclovir as effective for genital herpes, recurrent orofacial herpes, herpes zoster, and selected varicella infections when used appropriately and early in the disease course. The evidence base is strongest for herpes simplex infections and herpes zoster, while benefit depends on infection type, timing, and patient factors.
Medical Sources
- FDA Prescribing Information: ZOVIRAX (acyclovir) Capsules, Tablets, Suspension. Official label with indications, contraindications, warnings, and adverse reactions.
- DailyMed Prescribing Information: Acyclovir Tablets, USP. Official label with mechanism, indications, precautions, and adverse effects.
- Kłysik K, Pietraszek A, Karewicz A, Nowakowska M. “Acyclovir in the Treatment of Herpes Viruses – A Review.” Current Medicinal Chemistry, 2020. PubMed
- Fiddian AP, Brigden D, Yeo JM, Hickmott EA. “Acyclovir: an update of the clinical applications of this antiherpes agent.” Drugs, 1984. PubMed
Medical Information Notice
This educational summary is based on sources available at the time of review and is not a substitute for the official patient leaflet, product label, or assessment by a qualified healthcare professional.
