1 What is Famvir?

Brand: Famvir

Generic: Famciclovir

Famvir is an antiviral drug used for the treatment of the symptoms of shingles caused by herpes virus infection of the skin. This drug is used to treat and suppress cold sores and recurrent episodes of genital herpes infection. This drug is also used to treat recurrent herpes virus infections in HIV-infected patients. This drug cannot eradicate the virus but it can help relieve the pain and discomfort and help the sores heal faster.

This drug requires a prescription.

2 What to Know Before Using

Before using Famvir, the risks and benefits for your body should be discussed with your healthcare provider.

Inform your healthcare provider for any allergic reactions to these drugs or any other drugs, foods, dyes, preservatives, or animals.

Carefully read the label of non-prescription drugs for any possible allergic reaction or contraindications.

There are still no studies regarding relationship of age to the effects of famciclovir in children less than 18 years of age while safety and efficacy have not been established.

Studies in the elderly have not demonstrated any geriatric-specific problems that would limit the utility of Famciclovir. Adjustments in the dose of the elderly may be required since they are more likely to have age-related kidney disease.

No data is available regarding any harm to the fetus in animal studies but studies in pregnant women or animals have shown adverse effects. Studies demonstrating any risk to the fetuses are still inadequate. 

Infant risk is still undetermined when using this drug during breastfeeding. Discuss with your healthcare professional about potential risks and benefits of taking this drug while breastfeeding.

Drugs should not be taken together to prevent any interactions but in necessary cases inquire your healthcare provider regarding the adjustments in dosage or any other necessary precautions to prevent any unwanted side effects. Inform your healthcare professional if you are taking any other prescription or non-prescription drugs.

Intake of specific food or using alcohol or tobacco with this drug is associated with an increased risk of certain side effects. Your healthcare professional can give you special instructions about the use of food, alcohol, or tobacco.

Inform your healthcare provider for any other medical problems such as:

  • Galactose intolerance, glucose-galactose malabsorption, severe lactase deficiency, or kidney disease.

3 Proper Usage

It is recommended to use Famvir within 48 hours after the symptoms of shingles begin to appear, or within 6 hours after the symptoms of recurrent genital herpes begin to appear.

Take this drug with or without food. It is recommended to take this drug for the full time of treatment to ensure complete drug therapy and prevent any relapses. The dose of this drug will be variable for different patients. The directions on the label or the prescription by your healthcare professional should be followed.

The dosage of this drug you take depends on the medical problem for which you are using this drug.

  • Adults with shingles are given 500 milligrams every eight hours for seven days.
  • Use and dose in children must be determined by your healthcare professional. For suppression of recurrent genital herpes in adults, it is recommended to take 250 milligrams two times a day for up to one year.
  • Use and dose must be determined by your healthcare professional. Adults with recurrent genital herpes are given 1000 milligrams two times a day for one day.
  • Use and dose in children must be determined by your healthcare professional. 
  • Adults with recurrent cold sores are given 1500 milligrams as a single dose.
  • Adult with HIV-infection and recurrent herpes infections are given 500 milligrams two times a day for seven days. Use and dose in children must be determined by your healthcare professional.

A missed dose should be taken as soon as possible. However, skip the missed dose and go back to your regular dosing schedule if it is almost time for your next dose.

Store the drug in a closed container at room temperature, away from heat, moisture, and direct light.

Keep from freezing. Keep out of the reach of children.

Dispose any outdated or expired drugs and ask your healthcare professional for the proper disposal of the drugs.

4 Precautions To Take

In using Famvir, you must be careful and take some precautions as advised by your doctor.

Consult with your healthcare professional if your symptoms do not improve or if they become worse within a few days. It is recommended to keep the areas affected by herpes clean and dry as possible.

To avoid irritating the sores, it is recommended to wear loose-fitting clothing. This drug may cause dizziness, drowsiness, or reduced alertness.

Do not drive, use machines, or do anything else that could be dangerous if any of these side effects occur while taking this drug.

Avoid having sex when lesions are present as this drug does not prevent the sexual transmission of genital herpes.

5 Potential Side Effects

As with many medications, there are several potential side effects associated with Famvir.

Side effects may vary for each individual and prompt medical attention should be given if they occur. Seek advice from your healthcare professional immediately if you experience any unusual symptoms such as:

  • Black, Tarry stools
  • Bleeding gums
  • Blistering, Peeling, or Loosening of the skin blood in urine or stools
  • Chills
  • Clay-colored stools
  • Cough
  • Dark urine
  • Dizziness
  • Fever, Joint or Muscle pain
  • Loss of appetite
  • Pinpoint red spots on the skin
  • Red, irritated eyes
  • Sore throat
  • Sores
  • Ulcers or White spots in the mouth or on the lips
  • Unpleasant breath odor
  • Unusual bleeding or bruising
  • Vomiting of blood
  • Yellow eyes or skin

Some side effects may occur that usually do not need medical attention. As your body adjusts to the medicine, the side effects will slowly disappear.

Ask your healthcare professional about ways to prevent or reduce some of these side effects. If any of the following side effects persists, or are inconvenient, or if you notice any other effects, or if you have any questions about them, consult with your health care professional.

Report any side effects to the FDA hotline at 1-800-FDA-1088.

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