Famvir
® (
famciclovir) is a prescription antiviral medication used to treat the following conditions:
- Shingles in people with normal immune systems
- Recurring genital herpes in people with normal immune systems
- Recurring cold sores in people with normal immune systems
- Herpes simplex infections (including cold sores and genital herpes) in people with HIV or other conditions that weaken the immune system.
(Click Famvir Uses for more information on what the drug is used for, including possible off-label uses.)
It is made by Novartis Pharmaceuticals.
Shingles, genital herpes, and cold sores are caused by viruses. Once a person has been infected with these viruses, the virus never goes away. It remains inactive in certain nerve cells of the body, waiting to become active again. Famvir is an antiviral medication that helps the body fight the infection. It does this by preventing the virus from multiplying.
Several studies have looked at how well Famvir treats shingles, genital herpes, and cold sores.
Shingles
In previous studies that looked at using Famvir for
shingles, the medication helped shingles lesions heal faster and helped reduce pain. It also helped to prevent nerve pain associated with shingles. Studies have also suggested that Famvir is more effective when started within the first 48 hours after symptoms appear, and that it works better in people over 50 years old.
Genital Herpes
Previous studies have also evaluated Famvir for treating recurring
genital herpes in people who experience more than six outbreaks per year. In these studies, taking Famvir at the first signs of a genital herpes outbreak decreased the time until the lesions were healed and decreased the time until all of the symptoms were gone.
Studies have also shown that taking it every day can help prevent recurring genital herpes outbreaks. One study in people with six or more genital herpes outbreaks per year showed that after one year, 29 percent of people had not experienced a single outbreak, compared to only 6 percent of those not taking it.
Cold Sores
In previous studies, taking Famvir within one hour of the onset of
cold sore symptoms helped
cold sores heal faster and decreased the time people experienced pain and tenderness.
Herpes in People With HIV
One study compared Famvir to oral
acyclovir (
Zovirax®) for treating herpes simplex infections (such as cold sores or genital herpes) in people with
HIV. This study showed that Famvir is just as good as acyclovir for treating these conditions.
When and How to Take Famvir
Some general considerations for when and how to take the medication include:
- It comes in tablet form and is taken by mouth. For some uses, it is taken every day; for other uses, it is taken just for a day or for a week.
- The medication can be taken with or without food. If it bothers your stomach, try taking it with food.
- For the medication to work properly, it must be taken as prescribed. Make sure to take Famvir as your healthcare provider prescribes.
The dose of Famvir that your healthcare provider recommends will vary depending on a number of factors, including:
- The condition being treated
- Other medications you may be taking
- Other medical conditions you may have.
As always, do not adjust your dose unless your healthcare provider specifically instructs you to do so.
As with any medicine, side effects are possible with Famvir. However, not everyone who takes the drug will experience side effects. In fact, most people tolerate it quite well. If side effects do occur, in most cases they are minor and either require no treatment or can easily be treated by you or your healthcare provider. Serious side effects are less common.
Common side effects of Famvir include, but are not limited to:
(Click Side Effects of Famvir to learn more about possible side effects, including potentially serious side effects that you should report immediately to your healthcare provider.)
Drug Interactions With Famvir
What Should I Tell My Healthcare Provider?
You should talk with your healthcare provider prior to taking Famvir if you have:
- Kidney disease, including kidney failure (renal failure)
- Very severe lactose intolerance
- Galactose intolerance
- Any allergies, including allergies to food, dyes, or preservatives.
Also let your healthcare provider know if you are:
You should also make sure to tell your healthcare provider about all other medicines you are currently taking, including prescription and non-prescription medicines, vitamins, and herbal supplements.
What If I Overdose on Famvir?
It is not known what symptoms to expect from an overdose. People who take too much
acyclovir, a similar medication, may have overdose symptoms that could include:
- Agitation
- Coma
- Seizures
- Lethargy
- Kidney damage.
If you happen to overdose, seek medical attention immediately.
The medication should be stored at room temperature, away from moisture and heat. Famvir tablets should be stored in an airtight container.
Keep Famvir and all other medications out of the reach of children.
What Should I Do If I Miss a Dose?
If you do not take your Famvir as scheduled, take your missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule. Do not take a double dose.
Famvir tablets are available in the following strengths:
- Famvir 125 mg
- Famvir 250 mg
- Famvir 500 mg.
Is There a Generic Version of Famvir?
Currently, both brand-name and generic versions of Famvir are licensed for sale
(see Generic Famvir).
