Penciclovir
Penciclovir is an antiviral medication used to treat infections caused by alpha herpes viruses, most commonly herpes simplex virus (HSV). It works by inhibiting viral DNA replication, helping to reduce the severity and duration of symptoms such as cold sores. This topical treatment is typically applied directly to the affected area at the first sign of a herpes outbreak.
Penciclovir is a topical antiviral cream used to treat cold sores caused by herpes simplex virus infections.
Key facts at a glance
- ATC
- D06BB06
- RxNorm
- 59839
- Generic
- Penciclovir
- Class
- atc-d06
- Brands
- Denavir
- Availability
- rx
- Lactation
- unknown
- Routes
- topical
- Forms
- cream
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Penciclovir is indicated for the treatment of recurrent herpes labialis (cold sores) in immunocompetent adults. It may also have applications against other alpha herpes virus infections when used in topical or systemic formulations.
Penciclovir is a guanosine analog antiviral agent that inhibits viral DNA polymerase. Once phosphorylated by viral thymidine kinase, the active form interferes with viral DNA synthesis, preventing the virus from replicating and spreading to adjacent healthy cells.
For topical use only; apply at the first sign of symptoms for maximum effectiveness. Not a cure for herpes infections as the virus remains dormant in the body. Safety in immunocompromised patients and children has not been fully established. Wash hands before and after application to avoid spreading the infection.
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed July 26, 2026. · Read our editorial policy