ACTION AND MECHANISM

- [ANTIVIRAL]. Penciclovir has demonstrated in vivo and in vitro activity against herpes simplex viruses (types 1 and 2) and varicella-zoster virus. Penciclovir targets virus-infected cells, where it is rapidly and efficiently converted to triphosphate (via viral thymidine kinase). Penciclovir triphosphate persists in infected cells for over 12 hours, during which time it inhibits viral DNA replication. It has half-lives of 9, 10, and 20 hours in cells infected with varicella-zoster virus, herpes simplex virus type 1, and type 2, respectively. Concentrations of penciclovir triphosphate are only barely detectable in uninfected cells treated with penciclovir. Consequently, uninfected cells are unlikely to be affected by therapeutic concentrations of penciclovir.

SENIORS

No specific problems have been described in this age group. Doses are similar to those used in adults.

PATIENT ADVICE

- It should be applied at intervals of approximately 2 hours during the day.
- Treatment should be continued for 4 days.

- Avoid contact with eyes or mucous membranes.
- Administer medication as soon as possible after the first symptoms appear.
- Complete the full course of treatment even if symptoms have improved.

CONTRAINDICATIONS

- Known hypersensitivity to penciclovir, famciclovir or to the other components of the formulation, e.g. propylene glycol

PREGNANCY

FDA Category B - It is unlikely that there will be any adverse effects when the cream is used in pregnant and/or breastfeeding women since the systemic absorption of penciclovir after topical administration has been shown to be minimal - Studies with intravenous penciclovir have been conducted in experimental animals with doses equivalent to 1200 times higher than those recommended for clinical use by topical route, and no embryotoxic and/or teratogenic effects have been recorded in the species - Since the safety of penciclovir in pregnant women has not been established, it should only be used during pregnancy when recommended by a physician and if the potential benefits are considered to outweigh the risk associated with treatment.

PHARMACOKINETICS

Topical route - In a study in human volunteers, penciclovir was not quantifiable in plasma and urine after application of daily doses of 180 mg of penciclovir (approximately 67 times the proposed daily clinical dose) for 4 days to covered skin.

INDICATIONS

- [HERPES SIMPLEX LABIAL]: Treatment of cold sores.

LACTATION

- Studies in rats show that penciclovir is excreted in the breast milk of females receiving famciclovir (famciclovir; oral form of penciclovir, converted in vivo to penciclovir). There is no information regarding the elimination of penciclovir in human milk, so it should only be used during breastfeeding when recommended by a physician and if the potential benefits are considered to outweigh the risks associated with treatment.

CHILDREN

There is no clinical experience in children under 16 years of age.

RULES FOR CORRECT ADMINISTRATION

Apply at approximately two-hour intervals throughout the day. Apply with a clean finger or a single-use applicator (with applicators), using the required amount based on the size of the affected area.

POSOLOGY

- Adults (including those over 16 years of age and the elderly): 1 application every 2 hours during the day, continuing for 4 days. Treatment should begin as soon as possible after the first sign of infection.

PRECAUTIONS

- Avoid contact with eyes. - Application on mucous membranes: Use only on labial and perioral herpes. Application on mucous membranes is not recommended. - Immunosuppression: In severely immunosuppressed patients (e.g., patients with AIDS or bone marrow transplant recipients), in cases of severe illness or frequent recurrences, oral treatment should be considered. Such patients should be encouraged to consult their physician regarding treatment for any infection.

PRECAUTIONS RELATED TO EXCIPIENTS

- Because it contains cetostearyl alcohol, it may cause local skin reactions, such as contact dermatitis.

ADVERSE REACTIONS

The most characteristic side effects are:- Dermatological alterations (<3%): sensation of [SKIN IRRITATION], itching and numbness.

OVERDOSE

Symptoms: Systemic adverse effects are unlikely when taken orally, due to the poor oral absorption of penciclovir. May cause oral irritation. Treatment: There is no specific treatment.

COMPOSITION

PENCICLOVIR (TOPICO): 10 MILLIGRAMS
PROPYLENE GLYCOL (EXCIPIENT): 0
CETOSTEARYL ALCOHOL (EXCIPIENT): 0