Famvir Vs. Valtrex

Famvir and Valtrex are both antiviral prescription drugs that treat herpes viruses and illnesses caused by those viruses, such as cold sores, shingles (herpes zoster), and chicken pox in both adults and children. Neither Famvir nor Valtrex will cure these conditions, but they will help ease the symptoms of herpes-related infections, slow their progression, and keep the infections from coming back.

Identification

• The generic name for Famvir is famciclovir, and the generic name for Valtrex is valacyclovir. Famvir comes in white, round or oval tablets coated with a protective film in 125, 250, or 500 mg doses. Valtrex comes in unscored 500 mg or partially scored 1g tablet form, or an oral suspension (liquid) form in either 25 or 50 mg doses. Both Famvir and Valtrex are only available by prescription and are used to treat adults suffering from cold sores, genital herpes or shingles (herpes zoster), and children suffering from cold sores or chicken pox.

Dosage

• Famvir is taken for shingles in 500 mg doses taken every eight hours over seven days, and for genital herpes in 125 mg tablet doses taken twice daily over five days. Valtrex tablets or oral suspension drops treats shingles if taken three times a day over seven days. The first sign of genital herpes is treated with 1g tablet doses taken twice daily over 10 days. Recurring episodes are treated with 500 mg tablet doses taken twice daily over three days. Both Famvir and Valtrex can be administered with or without food, and tablets should be taken with a full glass of water.

Side Effects

• Famvir may lose its effectiveness if taken with other medications, such as probenecid (Benemid), a medication that treats an arthritic condition called gout. Valtrex may interact with other medications that can cause kidney malfunction, such as lithium and methotrexate; arthritis medications such as acetaminophen, ibuprofen, and naproxen; medications to prevent organ transplant rejection or to treat ulcerative colitis; antibiotics administered intravenously, antiviral medications, and certain medications used to treat cancer.

Side Effects

• Some people may be allergic to Famvir or Valtrex, and should go to an emergency room if they break out in hives, have trouble breathing, or experience facial swelling. Famvir could also cause nausea, diarrhea and vomiting, headaches and dizziness, sleeplessness or confusion, or skin rashes. Valtrex may cause nausea, vomiting and stomach pain, high blood pressure and a fast heartbeat, depression, mania, aggression and hallucinations, joint pain and headaches, menstrual problems, hepatitis or, in severe cases, coma.

Warnings

• People shouldn't take Famvir if they're allergic to penciclovir cream, if they have an immune deficiency disease such as HIV or kidney disease, or if they've had a kidney or bone marrow transplant. People who have adverse reactions to Valtrex or similar drugs such as valacyclovir or acyclovir (Zovirax) should tell their doctor, and people who are already taking medications for kidney disease may need to take smaller doses of both medications or avoid taking them altogether.