Antivirals for Shingles
How It Works
Antiviral medicines prevent the virus
shingles from multiplying. These medicines shorten the
period of rash, decrease pain during the active stage of the illness, and
reduce the possibility of getting complications of shingles, such as
postherpetic neuralgia. Antivirals may be taken orally
(by mouth) or injected intravenously (in a vein).
Why It Is Used
Anyone who has shingles can use
antivirals, but antivirals are particularly beneficial for adults older than 50
and people with weak
immune systems. They are also used for people with
severe rash and those who have rash near an eye and/or on the forehead.
How Well It Works
Antivirals may reduce the severity
of shingles and speed healing. When acyclovir, famciclovir, or valacyclovir are
taken within 3 days of getting shingles, these medicines can significantly
reduce the duration of pain associated with shingles. These medicines also
reduce the pain caused by postherpetic neuralgia.1, 2
Antivirals have few side effects but may
cause headache, nausea, and loss of appetite.
See Drug Reference
for a full list of side effects. (Drug Reference is not available in all
What To Think About
If you have kidney problems, you
may need to take less than the typical dosage of antiviral medicine. Before you
start antiviral treatment, be sure your doctor is aware of your other medical
If you have a
weakened immune system, as may happen to people with
diseases such as
diabetes, your doctor may inject antiviral medicines
into your vein (intravenously).
Topical antivirals (put
on the skin) do not help treat shingles.
Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.
Habif TP, et al. (2005). Herpes zoster (shingles). In Skin Disease: Diagnosis and Treatment. 2nd ed., pp. 210-215. Philadelphia: Elsevier Mosby.
Watson P (2010). Postherpetic neuralgia, search date December 2009. Online version of BMJ Clinical Evidence: http://www.clinicalevidence.com.