Thank you, both, for your responses. The antiviral is acyclovir, the same as prescribed to your husband, ThnKnPos, and she's taking it at the same time as the meth. 400 mg of the antiviral, 2.5 mg x 6 tablets of the meth once a week, both for 4 - 6 months. Also folic acid on the days she's not taking the meth. I read about the acyclovir and it's interesting that it's also prescribed for the chicken pox / shingles virus, among other viruses. She had shingles about 8 years ago, way before the diagnosis of LGL or before any of us had ever even heard of it.