This medication is used to treat herpes infections of the skin, mouth, mucous membranes, genital herpes, herpes zoster (shingles), and chickenpox in some individuals. This medication does not cure herpes, but relieves the pain and may make the infection clear faster.

Begin taking this medication as soon as symptoms appear. Take this medication as directed. Ask your doctor or pharmacist if you have any questions. Try to take the medication at evenly spaced intervals throughout the day and night. This will ensure a constant blood level of the medication and is most effective.

This medication may cause stomach upset, loss of appetite, nausea, vomiting, diarrhea, headache, dizziness or weakness. These effects should disappear in a few days as your body adjusts to the medication. If they persist or become worse, inform your doctor. Notify your doctor if you experience: numbness or tingling of the hands or feet, leg pain, sore throat, skin rash, change in the amount of urine. An allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs.

This medication should be used cautiously during pregnancy only if clearly needed. It is not known if this medication appears in breast milk. Consult with your doctor before breast-feeding.

This medication may interact with other drugs used to treat viral infections. Talk to your pharmacist or physician if you are taking this with other drugs.

If you miss a dose, take as soon as remembered; do not take if it is almost time for the next dose, instead, skip the missed dose and resume your usual dosing schedule. Do not "double-up" the dose to catch up.

Store at room temperature away from sunlight and moisture.