Generic name: Penciclovir.

Denavir is an antiviral. It works by interfering with reproductive process of the herpes virus. 

Quick Facts About Denavir


Used to treat cold sores caused by various strains of herpes viruses.

Denavir Dosage

Begin use as soon as cold sore(s) appear. Apply cream to cold sores every 2 hours, during waking hours, for 4 days. Avoid contact with eyes or other mucous membranes.

  • Usual adult dose:  thin film of cream applied to each cold sore every 2 hours, during waking hours.
  • Usual child dose: not prescribed for children under 18 years.
  • Missed dose: take as soon as possible, unless within 45 minutes of next dose. In that case, do not take missed dose; go back to regular schedule. Do not double doses.

Denavir Side Effects

Overdose symptoms:

none reported; however, if you suspect an overdose, immediately seek medical attention.

More common side effects: headache, redness, swelling.

Less common Denavir side effects: skin reaction. Rare side effects: numbness at application site, rash, taste changes.


No known Denavir drug interactions.

No known food/other substance interactions.

Special Cautions

Effects of Denavir on pregnant women and nursing mothers not known. If pregnant, planning to become pregnant, or breastfeeding, inform your doctor immediately.

No special precautions apply to seniors.

Not generally prescribed for children.

  • Should not use if sensitive or allergic to Denavir.

Note: provides accurate and independent information prescription pills, over-the-counter medicines and natural products. This material is provided for educational purposes only and is not intended for medical advice, diagnosis or treatment. If you have questions about  dosage, or Denavir side effects, please contact your healthcare provider.