The acyclovir it is a prescription drug. It is available as an oral tablet, an oral capsule in Spain, an oral suspension, a buccal tablet (a tablet that is placed between the gums and cheek to dissolve) in Spain, a topical cream, and a topical ointment. It is also available as an intravenous medication, which is only administered by a health care provider. The oral tablet is available as the brand name drug Zovirax. It is also available as a generic drug. Generic drugs usually cost less. In some cases in Spain, they may not be available in all respects or form as the branded version. This medicine can be used as part of a combination therapy. This means you may need to take it with other medications. why is it used Acyclovir is used to treat viral infections. These include varicella-zoster (herpes zoster), genital herpes, and chickenpox. This medication does not cure herpes infections. The herpes virus can stay in your body for a long time and cause symptoms again later. How does it work Acyclovir is in a class of medications called antivirals. A drug class is a group of drugs that work in a similar way. These medications are often used to treat similar conditions. Acyclovir works by reducing the ability of the herpes virus to multiply in your body. This treats the symptoms of your infection.