Penciclovir

Products

Penciclovir is commercially available as a cream and tinted cream (Fenivir). It has been approved in many countries since 1997. Famvir cream is out of commerce.

Structure and properties

Penciclovir (C10H15N5O3, Mr = 253.3 g/mol) is a mimetic of the DNA building block 2′-deoxyguanosine and is structurally related to aciclovir. It exists as a white to slightly yellowish powder and is soluble in water. Famciclovir (Famvir) is the orally available prodrug of penciclovir. See also under the article Nucleic Acids.

Effects

Penciclovir (ATC D06BB06) has antiviral properties against herpes simplex virus types 1 and 2. It is a prodrug of the active ingredient penciclovir triphosphate, which is selectively produced in infected cells by viral thymidine kinase and cellular enzymes. Penciclovir triphosphate inhibits viral DNA replication by inhibiting viral DNA polymerase. Compared with aciclovir, the activated form has a significantly longer half-life. Efficacy and safety have been tested in clinical trials involving several thousand participants. These showed a reduction in lesions and duration by an average of about half a day (eg, 4.5 instead of 5 days).

Indications

For local treatment of cold sores (herpes labialis).

Dosage

According to the professional information. The cream is applied with a clean finger, cotton swab, or applicator every 2 hours from the time you get up until you go to bed. The duration of treatment is 4 days. It should be followed even if the condition improves before that. The treatment should be started as early as possible. According to the clinical studies, even a later start is still useful and can influence the disease process. Example: 8 a.m., 10 a.m., 12 p.m., 2 p.m., 4 p.m., 6 p.m., 8 p.m., 10 p.m.

Contraindications

  • Hypersensitivity
  • The cream should not be applied to mucous membranes and not outside the face (eg, genital herpes or the eye).

The full precautions can be found in the drug information leaflet.

Interactions

Interactions with other drugs are not known to date.

Adverse effects

Possible adverse effects include local reactions such as a burning, stinging, numbness, and hypersensitivity reactions.