Shingles and Chickenpox

Shingles and Chickenpox (Varicella-Zoster Virus) - Treatment for an Acute Shingles Attack

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Acyclovir (Zovirax), famciclovir (Famvir), and valacyclovir (Valtrex) are approved for shingles. Acyclovir is the oldest, most studied of these drugs, but either famciclovir (Famvir) or valacyclovir (Valtrex), which are both metabolized into acyclovir, are now preferred to treat herpes zoster in most patients. They relieve symptoms better than acyclovir and require fewer daily doses (typically three) than the five doses needed with acyclovir.

Because herpes zoster tends to resolve fairly quickly in young adults, these drugs are generally reserved for patients at greatest risk for complications or persistent pain. They include:

Elderly people

Those with infections that threaten the eye

Patients who are HIV positive or immunocompromised in other ways

Patients whose infection covers a larger-than-average surface area of the skin

Those with very severe pain

These drugs appear to have little or no harmful effect on healthy cells and can penetrate most body tissues, including cerebrospinal fluid. Evidence to date suggests that they are safe during pregnancy.

Possible side effects of nucleoside analogues include rash, headache, fatigue, tremor, nausea and vomiting. Seizures are a very rare side effect. Patients with AIDS or other diseases that compromise the immune system are at increased risk for kidney damage and blood clots. Patients with suppressed immune systems are also more likely to have viral resistance to these drugs. These drugs are safe to take during pregnancy.

Foscarnet. Foscarnet (Foscavir) is a powerful antiviral drug known as a pyrophosphate analogue. It is used in cases of VZV strains that have become resistant to acyclovir and similar drugs. Administered intravenously, the drug can have toxic effects. It can impair kidney function (which is reversible) and cause seizures. Fever, nausea, and vomiting are common side effects. It can also cause ulcers on genital organs. As with other drugs, it does not cure shingles.

Brivudin. Brivudin (Helpin, Zostex) is another anti-viral drug, but it is not available in the U.S. It needs to be taken only once a day.