Famciclovir Tablet: Uses, Dosage, Side Effects, Precautions and Alternates

Quick overview

Famciclovir Tablet is a prescription antiviral medicine used to treat and manage infections caused by herpes viruses, including shingles, genital herpes, and cold sores. It does not cure herpes infections, but it helps relieve pain and discomfort and helps sores heal faster. It belongs to the antiviral drug class and works by stopping the virus from multiplying further.

What is Famciclovir Tablet

Famciclovir is a prescription antiviral tablet used to treat and manage infections caused by the herpes family of viruses, including shingles, genital herpes, and cold sores. It does not cure herpes infections, but it helps relieve pain and discomfort and helps sores heal faster.

Famciclovir Tablet uses

• Shingles (herpes zoster) - treats painful skin rashes and helps prevent long-term nerve pain when started early
• Genital herpes - treats active or recurrent outbreaks and can be taken daily to reduce future episodes
• Cold sores (herpes labialis) - treats recurrent outbreaks of fever blisters around the mouth
• Recurrent herpes infections of the lips, mouth, and genitals in people with HIV infection

Benefits of Famciclovir Tablet

• Treats active herpes outbreaks and reduces severity, pain, and duration of sores
• Speeds up healing of blisters
• Can reduce how often outbreaks come back when used as suppressive therapy
• Helps relieve pain and discomfort from outbreaks

How Famciclovir Tablet works

Famciclovir is converted by the body into an active form called penciclovir, which blocks the virus from making new DNA. This stops the virus from multiplying further, which reduces symptoms and helps control the infection, though it does not remove the virus from the body completely.

Famciclovir Tablet dosage

Take famciclovir as soon as possible when you first notice symptoms like burning, itching, or tingling. Famciclovir may be taken with or without food. Keep taking famciclovir for the full course of treatment, even if your symptoms begin to clear up after a few days. Do not miss doses and do not take it more often or for longer than your doctor ordered.

If you miss a dose, take it as soon as you remember, but if it is almost time for your next dose, skip the missed dose and go back to your regular schedule; do not double up. This medicine does not prevent sexual transmission of genital herpes, so avoid sexual contact when sores are present.

Children: use and dosing must be determined by a doctor, since safety and effectiveness in children under 18 have not been established.

Use exactly as prescribed by your doctor or pharmacist.

Available forms and strengths

• Tablet (125 mg, 250 mg, 500 mg oral tablets)

Side effects of Famciclovir Tablet

Common

• Headache
• Nausea
• Diarrhea or stomach pain
• Fatigue or unusual tiredness
• Dizziness or mild sleepiness
• Cramps
• Heavy bleeding

Serious

• Black, tarry stools
• Bleeding gums
• Blistering, peeling, or loosening of the skin
• Blood in urine or stools
• Chills
• Clay-colored stools
• Cough
• Dark urine
• 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 lips
• Unusual bleeding or bruising
• Vomiting of blood
• Yellow eyes or skin
• Signs of severe allergic reaction such as trouble breathing, facial swelling, or severe skin rashes/blistering

Warnings and precautions

• Famciclovir does not cure herpes infections and does not completely prevent spreading the virus to others.
• This medicine does not prevent sexual transmission of genital herpes. Avoid having sex when sores are present to avoid infecting your partner.
• People with galactose intolerance, glucose-galactose malabsorption, or severe lactase deficiency should not use this medicine.
• Treatment works best when started at the very first sign of an outbreak, such as tingling, burning, or itching, or within a few hours to days of symptoms starting.
• You may not be able to get certain vaccines, such as the chickenpox vaccine, right before or while taking this medicine. Tell your healthcare provider about any vaccines you have had recently or have scheduled.
• It is not known if or how famciclovir could affect pregnancy or harm an unborn baby. Tell your healthcare provider if you are or plan to become pregnant so they can advise you.
• There are no adequate studies showing the risk to infants when this medicine is used during breastfeeding. Weigh the potential benefits against the potential risks with your doctor before taking it while breastfeeding.
• Famciclovir is processed through the kidneys and needs a lower dose if you have kidney disease, otherwise it can lead to acute kidney (renal) failure. Drinking plenty of water while taking it helps protect your kidneys.
• Tell your healthcare provider if you have liver problems before using this medicine.
• There are no known interactions between famciclovir and alcohol, but heavy drinking can slow your immune response and make it harder for your body to fight infection.
• This medicine may cause dizziness, drowsiness, or reduced alertness. Do not drive, use machines, or do anything that could be dangerous if you feel dizzy or are not alert while taking this medicine.

Storage

• Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.
• Keep from freezing.
• Keep out of the reach of children.
• Do not keep outdated medicine or medicine no longer needed.
• Ask your healthcare professional how you should dispose of any medicine you do not use.

When to see a doctor

Get emergency care right away if you have trouble breathing, swelling of the face, lips, mouth, tongue, or throat, or a severe skin rash or blistering, including peeling skin or red, irritated eyes.

Check with your doctor right away if you notice black tarry stools, bleeding gums, blood in urine or stools, fever, chills, cough, sore throat, yellowing of the skin or eyes, or unusual bleeding or bruising.

If your symptoms do not improve within a few days, or if they get worse, check with your doctor.

If you take too much famciclovir, get medical help right away or contact a poison control center.

Alternatives

• Docosanol cream
• Penciclovir cream
• Valacyclovir
• Acyclovir