Famciclovir, by Novarts.

Famvir tablets are used to treat herpes zoster, commonly referred to as "shingles," in adults. Shingles is a painful rash with raised, red pimples on the trunk of the body, usually the back. Because it is caused by the same virus that causes chickenpox, only people who have had chickenpox can get shingles. When prescribed for shingles, Famvir works best in people age 50 or over.

Famvir is also prescribed to treat attacks of genital herpes and to prevent future flare-ups. For people with HIV infections, it is used as a treatment for both genital and oral herpes. Famvir is an antiviral drug. Famvir slows the growth and spread of the herpes virus so that the body can fight off the infection. Famvir shortens the length of time that herpes symptoms are present.

Famvir is most effective if started within the first 48 hours after shingles first appears; treatment should be started at the first sign or symptom of genital herpes. Famvir treatment may not be effective if it is delayed more than 72 hours after the herpes zoster rash first appears or more than 6 hours after genital herpes becomes evident. Thus, it is important to see your doctor as soon as possible after symptoms appear.

For maximum benefit, take Famvir for the full time of treatment, even if your symptoms begin to clear up. Do not, however, take Famvir more often or for a longer time than directed. You may take Famvir with meals or in between.

Recommended dosage: - Herpes Zoster: The recommended dosage is 500 mg every 8 hours for 7 days. Therapy should be initiated promptly as soon as herpes zoster is diagnosed. No data are available on efficacy of treatment started greater than 72 hours after rash onset. - Herpes Simplex Infections: Recurrent genital herpes: The recommended dosage is 1000 mg twice daily for 1 day. Initiate therapy at the first sign or symptom if medical management of a genital herpes recurrence is indicated. The efficacy of Famvir (famciclovir) has not been established when treatment is initiated more than 6 hours after onset of symptoms or lesions. - Suppression of recurrent genital herpes: The recommended dosage is 250 mg twice daily for up to 1 year. The safety and efficacy of Famvir therapy beyond 1 year of treatment have not been established. - Recurrent herpes labialis (cold sores): The recommended dosage is 1500 mg as a single dose. Initiate therapy at the earliest sign or symptom of a cold sore (e.g. tingling, itching or burning). - HIV-Infected Patients: For recurrent orolabial or genital herpes simplex infection, the recommended dosage is 500 mg twice daily for 7 days.

Take the forgotten dose as soon as you remember. If it is almost time for your next dose, skip the one you missed and go back to your regular schedule. Never take two doses at the same time.

Side effects Side effects cannot be anticipated. If any develop or change in intensity, inform your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking Famvir. More common side effects may include: constipation, diarrhea, dizziness, fatigue, fever, headache, nausea, vomiting.