Famvir tablets contain the active ingredient famciclovir, which is an antiviral medicine used to treat infections with herpes viruses. (Famciclovir is also available without a brand name, ie as the generic medicine.)
The herpes viruses include the viruses that cause genital herpes (herpes simplex types 1 and 2) and the virus that causes chickenpox and shingles (varicella zoster). Famciclovir works by stopping these herpes viruses from reproducing and infecting more cells in the body.
Once inside the body famciclovir is converted into another antiviral medicine called penciclovir. Penciclovir is converted to a more active form inside cells of the body that are infected with herpes viruses. The activated penciclovir then works by blocking the action of a viral enzyme called DNA polymerase.
The herpes viruses need the DNA polymerase enzyme to copy their genetic material from RNA to DNA. This process is necessary for the viruses to multiply and continue to survive. By blocking the action of DNA polymerase, penciclovir prevents the herpes viruses from multiplying. This controls the infection and helps the immune system to deal with it.
This medicine is taken by mouth to treat herpes infections that cause shingles. It is also taken by mouth to treat genital herpes, and to prevent this infection coming back in people who suffer recurrent infections. Famciclovir is also valuable for preventing herpes simplex infections in people whose immune systems are suppressed and therefore cannot fight off infection, either due to disease, eg HIV and AIDS, or medical treatment, eg chemotherapy, high-dose corticosteroids, bone marrow transplant.
This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.
Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.
Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here does not mean that all people using this medicine will experience that or any side effect.
The side effects listed above may not include all of the side effects reported by the medicine's manufacturer.For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.
It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while taking this one, to ensure that the combination is safe.
Probenecid may decrease the excretion of famciclovir by the kidneys, leading to higher levels of famciclovir in the bloodstream.
Famciclovir tablets are also available without a brand name, ie as the generic medicine.