Acyclovir cream is used to treat cold sores (fever blisters; blisters that are caused by a virus called herpes simplex) on the face or lips. Acyclovir ointment is used to treat first outbreaks of genital herpes (a herpes virus infection that causes sores to form around the genitals and rectum from time to time) and to treat certain types of sores caused by the herpes simplex virus in people with weak immune systems. Acyclovir is in a class of antiviral medications called synthetic nucleoside analogues. It works by stopping the spread of the herpes virus in the body. Acyclovir does not cure cold sores or genital herpes, does not prevent outbreaks of these conditions, and does not stop the spread of these conditions to other people.
How to apply
Topical acyclovir cream is usually applied 5 times a day for 4 days. Acyclovir cream may be applied at any time during a cold sore outbreak, but it works best when it is applied at the very beginning of a cold sore outbreak, when there is tingling, redness, itching, or a bump but the cold sore has not yet formed.
Precautions
Your symptoms should improve during your treatment with topical acyclovir. If your symptoms do not improve or if they get worse, call your doctor.
Acyclovir cream and ointment are for use only on the skin. Do not let acyclovir cream or ointment get into your eyes, or inside your mouth or nose, and do not swallow the medication.
Acyclovir cream should only be applied to skin where a cold sore has formed or seems likely to form. Do not apply acyclovir cream to any unaffected skin, or to genital herpes sores.
Do not apply other skin medications or other types of skin products such as cosmetics, sun screen, or lip balm to the cold sore area while using acyclovir cream unless your doctor tells you that you should.
