Have chronic shingles with severe pain and stiffening of muscles in both legs. could valtrex (valacyclovir) be causing a lactic acid problem?

Valtrex (valacyclovir): It is unlikely that Valtrex (valacyclovir) is causing muscular aches. The most common side effects are nausea, headache, vomiting, dizziness, fatigue, rash, depression, and abdominal pain. However, it is known that Valtrex (valacyclovir) can give you joint pain. Shingles, can give you flu like symptoms including muscle pains. I hope you feel better soon.