Famvir is an antiviral medication used to treat certain viral infections. It is a prodrug of penciclovir, meaning it is converted into penciclovir in the body to exert its antiviral effects. Famvir is prescribed to treat infections caused by herpes viruses, including:

• Genital herpes (herpes simplex virus type 2) - Famvir is used to treat outbreaks of genital herpes and may also be used as a daily suppressive therapy to prevent recurrent outbreaks.
• Cold sores (herpes simplex virus type 1) - Famvir can shorten the duration of cold sore outbreaks and reduce symptoms when taken at the first sign of an outbreak. Shingles (herpes zoster) - For shingles, Famvir is given to reduce acute symptoms and help shorten the duration of the outbreak.
• Chickenpox - Famvir may be used in adults and certain children to treat chickenpox and reduce complications.

Mechanism of Action

Famvir works by inhibiting the replication of herpes viruses. Once converted into penciclovir in the body, it competes with one of the nucleotides (building blocks) the virus needs to replicate its DNA. This prevents the virus from multiplying and spreading.

Dosage and Administration

Famvir comes as tablets that are taken orally. The dosage depends on the type of viral infection being treated. For outbreaks of genital herpes, the typical Famvir dosage is 125mg taken twice daily for 5 days. Higher doses may be given for initial or severe outbreaks.

For shingles and chickenpox, the recommended dosage of Famvir is 500mg taken three times per day for 7 days. Famvir should be taken as soon as possible after symptoms appear for optimal results.

Side Effects

Most side effects of Famvir are mild and may include headaches, nausea, vomiting, dizziness, abdominal pain, fatigue. More severe side effects are possible but rare, including skin rashes, seizures, hallucinations, and liver problems.

Famvir is generally considered safe and effective when used as prescribed, but people with kidney problems may need dose adjustments. Like with any medication, follow dosage instructions carefully and speak to a doctor about any concerns. Prompt treatment with antivirals like Famvir can help shorten the duration of viral infections and reduce complications.