Zovirax is a brand name of an anti-viral topical medication whose chemical name is acycloguanosine (ACV), also known as aciclovir. It is also marketed under the names Cyclovir, Herpax, Acivir, Acivirax, and Zovir. It is a specific against the herpes simplex virus, which causes cold sores and genital herpes. The drug can also be used for treatment of varicella zoster, which causes chicken pox, and herpes zoster (shingles).
It was originally extracted from a Caribbean sponge, and is available in the United States by prescription.

The drug may be administered intravenously or even orally, although it has poor water solubility and so is least effective in oral form. As
a topical antiviral, which is the form of Zovirax ointment, it is used for treatment of initial outbreaks of oral or genital herpes (primarily).

Aciclovir has no effect on viruses in their inactive, dormant stages in the nervous system, and so is not a “cure” for herpes. It is only a treatment for an outbreak of the disease, which may recur thereafter.

How Zovirax Works

Applied to a herpes sore, Zovirax ointment operates to prevent the virus from multiplying. This reduces the number of viruses and helps the body’s immune system to fight the infection.

Zovirax is a “proto-drug,” meaning that it is administered in a less active form and is metabolized (after absorption through the skin) into a more active form.

It is extremely selective, having little effect on viruses other than its intended target (the effect on chicken pox virus is considerably less than on herpes, and it has no measurable effect at all on most non-herpes viruses).

This helps to reduce unintended consequences of use. Because of the way Zovirax operates, it can make the discomfort and sores of herpes disappear more quickly and shorten the time a victim is infectious, whether or not the victim has a healthy immune system.

How Zovirax Ointment Should Be Used

Zovirax ointment should not be ingested. (The same drug is available by prescription in tablets or injection, but the ointment is designed for topical use.) Disposable rubber gloves should be used in order to prevent spreading the herpes infection to other parts of the body or to other people. As with all prescription medications, Zovirax ointment should be used as prescribed.

Possible Side Effects of Zovirax Ointment

Side effects possible with Zovirax ointment include mild pain (usually an itch or burning sensation on the skin where the ointment is applied), and swelling or inflammation. Pain occurs in approximately thirty percent of patients, while itching occurs in four percent. Inflammation is rarer. In very rare cases, an allergic reaction produces a severe rash that spreads beyond the area of use.

Zovirax Ointment During Pregnancy Or Lactation

The ointment form of aciclovir is considered safe for use during pregnancy because very little of the drug is absorbed into the bloodstream. No fetal damage has been found in animal studies of aciclovir. Human studies have not been conducted, however. Despite the theoretically low risk of use of Zovirax ointment in pregnancy, a physician should be consulted. (Of course, an active genital herpes outbreak at the time of
delivery is a severe risk to the baby, requiring a C-section birth.)

Aciclovir does pass into the breast milk from the bloodstream. However, in the form of Zovirax ointment, because of the very small amounts of the drug absorbed into the bloodstream, it is not considered a risk for breastfeeding mothers. Again, consulting a physician is recommended, especially if a herpes lesion is located on the breasts themselves, as this increases any risk from the drug and also presents a danger of spreading the herpes infection.

Warnings And Counter-Indications

Zovirax ointment should not be used to treat herpes lesions located in the eyes, as the ointment may cause serious eye irritation. The ointment will not prevent the spread of the infection to other people, except by reducing the amount of time contagion is possible; while an active lesion is present, there is no evidence that the patient will not remain contagious.

Zovirax ointment is not a cure for herpes. Repeat outbreaks may occur at any time, and the victim will remain able to transmit the disease to
others whenever such an outbreak occurs (known or unknown, visible or otherwise).

The medication is most effective early in the course of the disease, and should be begun as soon as possible after the first outbreak.