Famvir

DRUG DESCRIPTION

The active ingredient in FAMVIR tablets is famciclovir, an orally administered prodrug of the antiviral agent penciclovir. Chemically, famciclovir is known as 2-[2-(2-amino-9H-purin-9-yl)ethyl]-1,3-propanediol diacetate. Its molecular formula is C14H19N5O4; its molecular weight is 321.3. It is a synthetic acyclic guanine derivative and has the following structure

FAMVIR (famciclovir) Structural Formula Illustration

Famciclovir is a white to pale yellow solid. It is freely soluble in acetone and methanol, and sparingly soluble in ethanol and isopropanol. At 25C famciclovir is freely soluble ( > 25% w/v) in water initially, but rapidly precipitates as the sparingly soluble (2%-3% w/v) monohydrate. Famciclovir is not hygroscopic below 85% relative humidity. Partition coefficients are: octanol/water (pH 4.8) P=1.09 and octanol/phosphate buffer (pH 7.4) P=2.08.

FAMVIR tablets contain 125 mg, 250 mg or 500 mg of famciclovir, together with the following inactive ingredients: hydroxypropyl cellulose, hydroxypropyl methylcellulose, lactose, magnesium stearate, polyethylene glycols, sodium starch glycolate and titanium dioxide.

What are the possible side effects of famciclovir (Famvir)?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Less serious side effects may include:

  • nausea, vomiting, stomach pain;
  • diarrhea,
  • headache, tired feeling;
  • dizziness, sleepiness;
  • mild itching or skin rash;
  • numbness or tingly feeling; or
  • confusion.

This is not a complete list of side effects and others may occur. Call your doctor for...

Read All Potential Side Effects and See Pictures of Famvir

What are the precautions when taking famciclovir (Famvir)?

Before taking famciclovir, tell your doctor or pharmacist if you are allergic to it; or to penciclovir; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: kidney problems.

This drug may rarely make you dizzy or drowsy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Limit alcoholic beverages.

This medication may contain lactose. If you have certain conditions such as galactose intolerance, severe lactase deficiency (not lactose or milk intolerance), or...

Read All Potential Precautions of Famvir


Famvir Consumer (continued)

SIDE EFFECTS: Headache, nausea, and diarrhea may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor immediately if any of these unlikely but serious side effects occur: mental/mood changes (such as agitation, slowed thinking, confusion, hallucinations), dizziness, drowsiness.

Tell your doctor immediately if any of these rare but serious side effects occur: change in the amount of urine, yellowing eyes/skin, easy bruising/bleeding.

A very serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction may include: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

PRECAUTIONS: Before taking famciclovir, tell your doctor or pharmacist if you are allergic to it; or to penciclovir; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: kidney problems.

This drug may rarely make you dizzy or drowsy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Limit alcoholic beverages.

This medication may contain lactose. If you have certain conditions such as galactose intolerance, severe lactase deficiency (not lactose or milk intolerance), or glucose-galactose malabsorption that require you to restrict your intake of lactose, consult your doctor or pharmacist before taking this medication.

Kidney function declines as you grow older. This medication is removed by the kidneys. Older adults may be more sensitive to the side effects of this drug, especially dizziness, drowsiness, confusion, and change in the amount of urine.

Famciclovir does not protect against the spread of genital herpes. To lower the chance of giving herpes to your partner, do not have sexual contact during an outbreak or if you have symptoms. You can spread genital herpes even if you do not have symptoms. Therefore, always use an effective barrier method (latex or polyurethane condoms/dental dams) during all sexual activity. Consult your doctor or pharmacist for more details.

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

It is not known if this medication passes into breast milk. It may have undesirable effects on a nursing infant. Consult your doctor before breast-feeding.


Famvir Patient Information Including Side Effects

Brand Names: Famvir

Generic Name: famciclovir (Pronunciation: fam SYE klo veer)

  • What is famciclovir (Famvir)?
  • What are the possible side effects of famciclovir (Famvir)?
  • What is the most important information I should know about famciclovir (Famvir)?
  • What should I discuss with my healthcare provider before taking famciclovir (Famvir)?
  • How should I take famciclovir (Famvir)?
  • What happens if I miss a dose (Famvir)?
  • What happens if I overdose (Famvir)?
  • What should I avoid while taking famciclovir (Famvir)?
  • What other drugs will affect famciclovir (Famvir)?
  • Where can I get more information?

What is famciclovir (Famvir)?

Famciclovir is an antiviral drug. It slows the growth and spread of the herpes virus so that the body can fight off the infection. Famciclovir will not cure herpes, but it can lessen the symptoms of the infections.

Famciclovir is used to treat infections caused by herpes viruses, including genital herpes, cold sores, shingles, and chicken pox.

There is no cure for herpes and famciclovir will not prevent you from developing symptoms in the future.

Famciclovir may also be used for other purposes not listed in this medication guide.

What are the possible side effects of famciclovir (Famvir)?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Less serious side effects may include:

  • nausea, vomiting, stomach pain;
  • diarrhea,
  • headache, tired feeling;
  • dizziness, sleepiness;
  • mild itching or skin rash;
  • numbness or tingly feeling; or
  • confusion.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What is the most important information I should know about famciclovir (Famvir)?

Take this medication for the entire length of time prescribed by your doctor. Your symptoms may get better before the infection is completely treated.

Treatment with famciclovir should be started as soon as possible after the first appearance of symptoms (such as tingling, burning, blisters).

Herpes infections are contagious and you can infect other people, even while you are being treated with famciclovir. Avoid letting infected areas come into contact with other people. Avoid touching an infected area and then touching your eyes. Wash your hands frequently to prevent passing the infection to others.

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