Several antiviral medications are available for the treatment of shingles, states WebMD. These include acyclovir, famciclovir and valacyclovir, which are sold under the brand names Zorivax, Famvir and Valtrex, respectively. Most patients take these medicines orally, but they are available in intravenous form as well.
Antiviral medicines do not kill the virus that causes shingles, but they stop it from multiplying, which shortens the duration of the rash and reduces pain, notes WebMD. Taking antiviral medication also reduces the risk of postherpetic neuralgia, a complication of shingles that causes severe pain and nerve problems that sometimes last for years. Results are best when the patient begins taking the medicine within three days of developing symptoms.