Antiviral medications for chickenpox

Examples

Antiviral medications can be taken by mouth (orally) or given by injection into a vein (intravenous, or IV). Acyclovir is the antiviral medication used most often to treat chickenpox (varicella). However, other antivirals may be used.

Antiviral eye ointments are also available. They can be used on your eyes to treat chickenpox blisters.

How It Works

Antiviral medications stop the growth of the chickenpox (varicella-zoster) virus.

Why It Is Used

Antiviral medications may be given to people who have been in contact with someone who has chickenpox. Antiviral medications are generally given to people who are more likely to become seriously ill or develop complications from chickenpox. These medications need to be started within 24 hours of the first signs of chickenpox rash.

Oral antivirals may safely be given to people who:

• Have long-term illnesses, such as skin or lung diseases.
• Are receiving short-term corticosteroid medication, such as people being treated for asthma.
• Are receiving long-term treatment with certain medications containing salicylates, such as people with arthritis.

Intravenous antivirals are usually recommended for:

• People with impaired immune systems.
• Pregnant women with serious complications of chickenpox.
• Babies born early or babies who have a low birth weight and whose mother had chickenpox.

Antiviral eye ointment is recommended for people who have chickenpox blisters in their eyes.

These medications are usually NOT recommended for:

• Healthy people as a way to prevent them from having chickenpox if they have been exposed to the illness.
• Pregnant women unless they have complications of chickenpox.

Parents of an otherwise healthy child may want their child to have an antiviral medication to shorten the time the child is ill or reduce the severity of symptoms. However, parents may choose not to give antiviral medications to their otherwise healthy child because his or her symptoms are not severe or the illness is not causing problems for the family.

Antiviral medications may work best to protect family members of a person with chickenpox from getting chickenpox.

• Often the first person in a family to get chickenpox is not able to get an antiviral medication soon enough (within 24 hours of the first sign of rash).
• Other family members have time to look for the first signs of chickenpox and watch for the chickenpox rash. At the first sign of rash, they can take an antiviral medication. Other family members are also more likely to have severe symptoms because they have been in close contact with someone who has chickenpox and have been exposed to higher concentrations of the virus.

How Well It Works

Antiviral medications may shorten the length of illness from chickenpox, cause fewer blisters to form, and help blisters heal faster.

Antiviral medications may reduce by 20% the number of days a person is sick with chickenpox (for example, from 5 days to 4) and the number of chickenpox spots (for example, from 200 spots to 160).

It is not known whether antiviral medications reduce the chance of developing complications of chickenpox. Antiviral medications may reduce the complications of chickenpox, such as varicella pneumonia, in people with impaired immune systems.

Side Effects

Antiviral medications have few side effects. They include:

• Headache or feelings of general illness (malaise).
• Nausea and vomiting.
• Diarrhea or constipation. This is rare.
• Kidney problems in people who receive large doses of acyclovir by rapid injection into a vein. This is rare.

The effect of antiviral medications on pregnant women and their fetuses is not known.

The effect of antiviral medications on immunity to chickenpox is not known.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

Consider the following when deciding whether to treat a family member with antiviral medications:

• Antiviral medications are expensive. The cost of treatment includes both the medication and visits to a health professional's office.
• Treatment with antiviral medications may reduce the length of time you can pass the chickenpox virus to other people.
• It is not clear whether antiviral medications reduce lost time from work, school, or day care.

Acyclovir (Zovirax) is the most prescribed antiviral medication. It has fewer side effects than the other antiviral medications. However, it does not reduce itching, nor does it stop the spread of the chickenpox virus from one person to another.

People who take acyclovir need to drink extra liquids to prevent kidney problems. People who have kidney problems need to take a lower dose of acyclovir.

Foscarnet is usually given if acyclovir is not successful in stopping the chickenpox virus.

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