| Click on "►" to expand:|
[×] Entry inhibitors
 BRAND NAMES
 MECHANISM OF ACTION
The antiviral compound penciclovir has in vitro inhibitory activity against herpes simplex virus types 1 (HSV-1) and 2 (HSV-2). In cells infected with HSV-1 or HSV-2, viral thymidine kinase phosphorylates penciclovir to a monophosphate form which, in turn, is converted to penciclovir triphosphate by cellular kinases. In vitro studies demonstrate that penciclovir triphosphate inhibits HSV polymerase competitively with deoxyguanosine triphosphate. Consequently, herpes viral DNA synthesis and, therefore, replication are selectively inhibited.
Treatment of recurrent herpes labialis (cold sores) that occur on the face and lips, in adults and children 12 years of age and older.
Apply a layer of Penciclovir cream to cover only the cold sore area or the area of tingling (or other symptoms) before the cold sore appears. Rub in the cream until it disappears. Apply the cream every 2 hours during waking hours for 4 days. Even though Penciclovir works at the blister stage, treatment should be started at the earliest sign of a cold sore (i.e. tingling, redness, itching, or bump).
Patients with known hypersensitivity to Penciclovir
No drug interaction studies have been performed. Due to minimal systemic absorption of topical Penciclovir, systemic drug interactions are unlikely.
 PREGNANCY AND LACTATION
- Pregnancy Category B (US). Penciclovir should be used during pregnancy only if clearly needed.
- Nursing Mothers: a decision should be made whether to discontinue the drug, taking into account the importance of the drug to the mother.
 SIDE EFFECTS
The most frequently reported side effect was headache. Common skin-related side effects of Penciclovir cream are application site reactions, local anesthesia, taste perversion, and rash.